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Sample records for ferrite films prepared

  1. Preparation and investigation of bulk and thin film samples of strontium ferrite

    Directory of Open Access Journals (Sweden)

    A Poorbafrani

    2008-07-01

    Full Text Available   In this article, bulk and thin film samples of strontium ferrite have been studied. Due to the high electrical resistivity in strontium ferrite, energy loss due to eddy currents reduces and because of this, it can be used in high frequency magnetic circuits. On the other hand, strontium ferrite has attracted much attention as a permanent magnet. At first, we study the preparation process of bulk samples of strontium ferrite by a solid state reaction technique. In preparation of samples, to optimize the magnetic properties, we have used the stoichiometry factor (n = Fe2O3 / SrO of 5.25. In addition, we have used additives such as CaO and SiO2 to control grain growth. The samples have been prepared in two series: Isotropic and Anisotropic. For preparation of anisotropic samples, the magnetic field of 1T has been used for orientation of the grains during the press. Then, X-ray diffraction, Scanning Electron Microscopy (SEM, EDAX analysis and Magnetometer, was used for analyzing and comparing of structural and magnetic properties of isotropic and anisotropic samples. The results indicate that, due to the applied magnetic field, the structural and Magnetic properties of anisotropic samples improved efficiently because of the orientation of the grains during the press. In the next stage, we used bulk samples to prepare strontium ferrite thin films by Pulsed Laser Deposition technique (PLD. The Si (111 substrate has been used to prepare the thin films. Then we have studied the microstructure of thin films by X-ray diffraction, SEM and EDAX analysis. These studies on different samples show that for the preparation of crystalline phase of strontium ferrite thin films, the substrate temperature must be higher than 800˚C. The optimum conditions for preparation of strontium, ferrite thin films have been achieved on the substrate temperature of 840˚C and oxygen pressure of 75 mtorr.

  2. Study of NiCuZn ferrite powders and films prepared by sol-gel method

    Institute of Scientific and Technical Information of China (English)

    Gao Liang-Qiu; Yu Guo-Jian; Wang Ying; Wei Fu-Lin

    2011-01-01

    This paper reports that a series of NiCuZn ferrite powders and films are prepared by using sol-gel method. The effects of raw material composition and the calcinate temperature on magnetic properties of them are investigated. The NiCuZn ferrite powders are prepared by the self-propagating high-temperature synthesis method and subsequently heated at 700 ℃~1000 ℃. The results show that NiCuZn ferrite powders with single spinel phase can be formed after heat-treating at 750 ℃. Powders obtained from Nio.4Cuo.2Zno.4Fe1.9O4 gel have better magnetic properties than those from gels with other composition. After heat-treating at 900 ℃ for 3 h, coercivity Hc and saturation magnetization Ms are 9.7 Oe (1 Oe = 80 A/m) and 72.4 emu/g, respectively. Different from the powders, NiCuZn films produced on Si (100) from the Ni0.4Cu0.2Zn0.4Fe2O4 gel formed at room temperature possess high properties. When heat-treating condition is around 600 ℃ for 6 min, samples with low Hc and high Ms will be obtained. The minimal Hc is 16.7 Oe and Ms is about 300 emu/cm3. In comparison with the films prepared through long-time heat treating, the films prepared through short heat-treating time exhibits better soft magnetic properties.

  3. Perpendicularly oriented barium ferrite thin films with low microwave loss, prepared by pulsed laser deposition

    Science.gov (United States)

    Da-Ming, Chen; Yuan-Xun, Li; Li-Kun, Han; Chao, Long; Huai-Wu, Zhang

    2016-06-01

    Barium ferrite (BaM) thin films are deposited on platinum coated silicon wafers by pulsed laser deposition (PLD). The effects of deposition substrate temperature on the microstructure, magnetic and microwave properties of BaM thin films are investigated in detail. It is found that microstructure, magnetic and microwave properties of BaM thin film are very sensitive to deposition substrate temperature, and excellent BaM thin film is obtained when deposition temperature is 910 °C and oxygen pressure is 300 mTorr (1 Torr = 1.3332 × 102 Pa). X-ray diffraction patterns and atomic force microscopy images show that the best thin film has perpendicular orientation and hexagonal morphology, and the crystallographic alignment degree can be calculated to be 0.94. Hysteresis loops reveal that the squareness ratio (M r/M s) is as high as 0.93, the saturated magnetization is 4004 Gs (1 Gs = 104 T), and the anisotropy field is 16.5 kOe (1 Oe = 79.5775 A·m-1). Ferromagnetic resonance measurements reveal that the gyromagnetic ratio is 2.8 GHz/kOe, and the ferromagnetic resonance linewith is 108 Oe at 50 GHz, which means that this thin film has low microwave loss. These properties make the BaM thin films have potential applications in microwave devices. Project supported by the Open Foundation of State Key Laboratory of Electronic Thin Films and Integrated Devices (Grant No. KFJJ201506), the Scientific Research Starting Foundation of Hainan University (Grant No. kyqd1539), and the Natural Science Foundation of Hainan Province (Grant No. 20165187).

  4. Co-containing spinel ferrite thin-film perpendicular magnetic recording media with Mn-Zn ferrite backlayer

    OpenAIRE

    Yamamoto, Setsuo; Kuniki, Hirofumi; Kurisu, Hiroki; Matsuura, Mitsuru

    2003-01-01

    Co-containing ferrite thin-film/Mn-Zn ferrite thin-film double-layered perpendicular media were prepared using reactive ECR sputtering and magnetron sputtering methods, and their magnetic and structural properties and recording characteristics were studied. The Mn-Zn ferrite thin-film backlayer had saturation magnetization of 3.5 kG and coercivity of 60 Oe. Reproduced voltage for the Co-containing ferrite thin-film/Mn-Zn ferrite thin-film double-layered medium was about twice of that for the ...

  5. Enhanced magneto-optical Kerr effect in rare earth substituted nanostructured cobalt ferrite thin film prepared by sol–gel method

    Energy Technology Data Exchange (ETDEWEB)

    Avazpour, L.; Toroghinejad, M.R. [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Shokrollahi, H., E-mail: Shokrollahi@sutech.ac.ir [Electroceramics Group, Department of Materials Science and Engineering, Shiraz University of Technology, Shiraz 13876-71557 (Iran, Islamic Republic of)

    2016-11-30

    Highlights: • The nanostructured rare earth doped Co-ferrite thin film was synthesized by the sol–gel method. • The coercivity of as high as 1.8 kOe is achieved for 20% substituted cobalt ferrite. • The average particle diameter of particulate film is decreasing by increasing substitute content. • Kerr spectra of films shifted to higher energies. • Kerr rotation angle increased to 1.65° for 0.1 Eu doped thin film. - Abstract: A series of rare-earth (RE)-doped nanocrystalline Co{sub x} RE{sub (1−x)} Fe{sub 2}O{sub 4} (x = 0, 0.1, 0.2 and RE: Nd, Eu) thin films were prepared on silicon substrates by a sol–gel process, and the influences of different RE{sup 3+} ions on the microstructure, magnetism and polar magneto-optical Kerr effect of the deposited films were investigated. Also this research presents the optimization process of cobalt ferrite thin films deposited via spin coating, by studying their structural and morphological properties at different thicknesses (200, 350 nm) and various heat treatment temperatures 300–850 °C. Nanoparticulate polycrystalline thin film were formed with heat treatment above 400 °C but proper magnetic properties due to well crystallization of the film were achieved at about 650 °C. AFM results indicated that the deposited thin films were crack-free exhibiting a dense nanogranular structure. The root-mean square (RMS) roughness of the thin films was in the range of 0.2–3.2 nm. The results revealed that both of the magnetism and magneto optical Kerr (MOKE) spectra of Co{sub x} RE{sub (1−x)} Fe{sub 2}O{sub 4} films could be mediated by doping with various RE ions. The Curie temperature of substituted samples was lower than pristine cobalt ferrite thin films. In MOKE spectra both dominant peaks were blue shifted with addition of RE ions. For low concentration dopant the inter-valence charge transfer related rotation was enhanced and for higher concentration dopant the crystal field rotation peak was enhanced

  6. Enhanced magneto-optical Kerr effect in rare earth substituted nanostructured cobalt ferrite thin film prepared by sol-gel method

    Science.gov (United States)

    Avazpour, L.; Toroghinejad, M. R.; Shokrollahi, H.

    2016-11-01

    A series of rare-earth (RE)-doped nanocrystalline Cox RE(1-x) Fe2O4 (x = 0, 0.1, 0.2 and RE: Nd, Eu) thin films were prepared on silicon substrates by a sol-gel process, and the influences of different RE3+ ions on the microstructure, magnetism and polar magneto-optical Kerr effect of the deposited films were investigated. Also this research presents the optimization process of cobalt ferrite thin films deposited via spin coating, by studying their structural and morphological properties at different thicknesses (200, 350 nm) and various heat treatment temperatures 300-850 °C. Nanoparticulate polycrystalline thin film were formed with heat treatment above 400 °C but proper magnetic properties due to well crystallization of the film were achieved at about 650 °C. AFM results indicated that the deposited thin films were crack-free exhibiting a dense nanogranular structure. The root-mean square (RMS) roughness of the thin films was in the range of 0.2-3.2 nm. The results revealed that both of the magnetism and magneto optical Kerr (MOKE) spectra of Cox RE(1-x) Fe2O4 films could be mediated by doping with various RE ions. The Curie temperature of substituted samples was lower than pristine cobalt ferrite thin films. In MOKE spectra both dominant peaks were blue shifted with addition of RE ions. For low concentration dopant the inter-valence charge transfer related rotation was enhanced and for higher concentration dopant the crystal field rotation peak was enhanced. The MOKE enhancement for Eu3+ substituted samples was more than Nd3+ doped cobalt ferrite films. The enhanced MOKEs in nanocrystalline thin films might promise their applications for magneto-optical sensors in adopted wavelengths.

  7. Characterization of perovskite film prepared by pulsed laser deposition on ferritic stainless steel using microscopic and optical methods

    Science.gov (United States)

    Durda, E.; Jaglarz, J.; Kąc, S.; Przybylski, K.; El Kouari, Y.

    2016-06-01

    The perovskite La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF48) film was deposited on Crofer 22 APU ferritic stainless steel by pulsed laser deposition (PLD). Morphological studies of the sample were performed using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Information about film thickness and surface topography of the film and the steel substrate were obtained using following optical methods: spectroscopic ellipsometry (SE), bidirectional reflection distribution function (BRDF) and total integrated reflectometry (TIS). In particular, the BRDF study, being complementary to atomic force microscopy, yielded information about surface topography. Using the previously mentioned methods, the following statistic surface parameters were determined: root-mean square (rms) roughness and autocorrelation length by determining the power spectral density (PSD) function of surface irregularities.

  8. Manganese ferrite thin films Part II: Properties

    NARCIS (Netherlands)

    Hulscher, W.S.

    1972-01-01

    Some properties of evaporated manganese ferrite thin films are investigated, e.g. resistivity, magnetization reversal, Curie temperature, Faraday rotation and optical absorption. The properties are partly related to the partial oxygen pressure present during a preceding annealing process.

  9. Direct formation of ferrite films in wet process

    Science.gov (United States)

    Abe, M.; Tanno, Y.; Tamaura, Y.

    1985-04-01

    We have prepared a polycrystalline Co-ferrite film by the electroless ferrite-plating technique of our invention [J. Appl. Phys. 55, 2614 (1984)] in an aqueous solution at 70 °C on substrates of organic compounds (polyethylene terephthalate, polymethyl methacrylate, polycarbonate, Teflon), a stainless steel, and a polyester fiber. We used no intermediate layer, which we needed previously to enhance the adhesion of the ferrite film to the surface. By exposing the organic substrates to an rf-excited air plasma, the wettability of the surface improved, which enhanced the adhesion of the film to the substrate. Here we have measured the adhesion by a cross-cut test. The plasma forms hydrophilic groups such as -OH and -COOH, which improve the wettability. The OH group adsorbs the metal ions in the reaction solution, initiating the ferrite film formation. The glass shows a strong adhesion to the film even when it is not exposed to the plasma, because the glass has the OH group on the surface inherently. The stainless steel does not enhance the adhesion by the plasma treatment because the plasma forms no OH group on the metal surface. The adhesion power higher than ˜10 kg/cm2 has been obtained between the Co-ferrite film and the glass (not plasma treated), the polyethylene terephthalate (plasma treated) and the Teflon (plasma treated).

  10. Barium Ferrite Films Grown by Laser Ablation

    NARCIS (Netherlands)

    Lisfi, A.; Lodder, J.C.; Haan, de P.; Smithers, M.A.; Roesthuis, F.J.G.

    1998-01-01

    Pulsed laser ablation (PLA) has been used to grow barium ferrite films on Al2O3 single crystal substrates. When deposition occurs in an oxidising atmosphere at high temperatures, the films are single BaFe12O19 phase, very well oriented with (001) texture, and exhibit a large perpendicular magnetic a

  11. Dielectric Spectroscopy of Localized Electrical Charges in Ferrite Thin Film

    Science.gov (United States)

    Abdellatif, M. H.; Azab, A. A.; Moustafa, A. M.

    2017-09-01

    A thin film of Gd-doped Mn-Cr ferrite has been prepared by pulsed laser deposition from a bulk sample of the same ferrite prepared by the conventional double sintering ceramic technique. The charge localization and surface conduction in the ferromagnetic thin film were studied. The relaxation of the dielectric dipoles after exposure to an external alternating-current (AC) electric field was investigated. The effect of charge localization on the real and imaginary parts of the dielectric modulus was studied. The charge localization in the thin film was enhanced and thereby the Maxwell-Wagner-type interfacial polarization. The increase in interfacial polarization is a direct result of the enhanced charge localization. The sample was characterized in terms of its AC and direct-current (DC) electrical conductivity, and thermally stimulated discharge current.

  12. High coercivity in nanostructured Co-ferrite thin films

    Indian Academy of Sciences (India)

    J H Yin; B H Liu; J Ding; Y C Wang

    2006-11-01

    Three methods including sol–gel, rf sputtering and pulsed laser deposition (PLD) have been used for the fabrication of high coercivity Co-ferrite thin films with a nanocrystalline structure. The PLD method is demonstrated to be a possible tool to achieve Co-ferrite films with high coercivity and small grain size at low deposition temperature. High coercivity, over 10 kOe, has been successfully achieved in Co-ferrite films with a thickness of ∼ 100 nm deposited using PLD with a substrate temperature at 550°C. The Co-ferrite films prepared by PLD at over 300°C on different substrates including amorphous glass, quartz and silicon exhibits an obvious (111) textured structure and possesses perpendicular anisotropy. Our study has also shown that the high coercivity is related with a large residual strain, which may induce an additional magnetic anisotropy (stress anisotropy) and at the same time serve as pinning centres, which can restrict the domain wall movement and therefore, increase the coercivity.

  13. Spinel ferrite thin-film synthesis by spin-spray ferrite plating

    Energy Technology Data Exchange (ETDEWEB)

    Hai, Tran Hoang; Van, Ha Thi Bich; Phong, Tran Canh; Abe, Masanori

    2003-04-01

    By spin-spray ferrite plating with optimizing conditions in the oxidizing and reaction solutions, we can synthesize polycrystalline ferrite film of spinel type (Fe, M){sub 3}O{sub 4}, where M=Fe, Co, Ni, Zn, etc., in low temperatures (<100 deg. C). By this method we can synthesize Co, Co-Ni ferrite for perpendicular magnetic recording media with high coercivity H{sub c} in the plane perpendicular to the film.

  14. Magnetic Properties of NiCuZn Ferrite Thin Films Prepared by the Sol-gel Method

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Ni0.4Cu0.2Zn0.4Fe2O4 thin films were fabricated on Si substrates by using the sol-gel method and rapid thermal annealing (RTA), and their magnetic properties and crystalline structures were investigated.The samples calcined at and above 600 ℃ have a single-phase spinel structure and the average grain size of the sample calcined at 600 ℃ is about 20 nm. The initial permeability μi, saturation magnetization Ms and coercivity Hc of the samples increase with the increasing calcination temperature. The sample calcined at 600 ℃ exhibits an excellent soft magnetic performance, which has μi=33.97 (10 MHz),Hc=15.62 Oe and Ms=228.877 emu/cm3. Low-temperature annealing can enhance the magnetic properties of the samples. The work shows that using the sol-gel method in conjunction with RTA is a promising way to fabricate integrated thin-film devices.

  15. Preparation and Characterization of Manganese Ferrite Aluminates

    Directory of Open Access Journals (Sweden)

    R. L. Dhiman

    2008-01-01

    Full Text Available Aluminum doped manganese ferrites MnAlxFe2−xO4 with 0.0≤x≤1.0 have been prepared by the double ceramic route. The formation of mixed spinel phase has been confirmed by X-ray diffraction analysis. The unit cell parameter `aO' is found to decrease linearly with aluminum concentration due to smaller ionic radius of aluminum. The cation distributions were estimated from X-ray diffraction intensities of various planes. The theoretical lattice parameter, X-ray density, oxygen positional parameter, ionic radii, jump length, and bonds and edges lengths of the tetrahedral (A and octahedral (B sites were determined. 57Fe Mössbauer spectra recorded at room temperature were fitted with two sextets corresponding to Fe3+ ions at A- and B-sites. In the present ferrite system, the area ratio of Fe3+ ions at the A- and B-sites determined from the spectral analysis of Mössbauer spectra gives evidence that Al3+ ions replace iron ions at B-sites. This change in the site preference reflects an abrupt change in magnetic hyperfine fields at A- and B-sites as aluminum concentration increases, which has been explained on the basis of supertransferred hyperfine field. On the basis of estimated cation distribution, it is concluded that aluminum doped manganese ferrites exhibit a 55% normal spinel structure.

  16. Pulsed-laser deposition of crystalline cobalt ferrite thin films at lower temperatures

    Science.gov (United States)

    Jiles, David; Raghunathan, Arun; Nlebedim, Ikenna; Snyder, John

    2010-03-01

    Cobalt ferrite thin films have been proposed for various engineering applications due to their exceptional magnetic, magnetoelastic, magnetotransport, magnetooptical properties. In this research, cobalt ferrite thin films were grown on SiO2/Si(100) substrates using pulsed-laser deposition (PLD) technique at substrate temperatures ranging from 250 C to 600 C. It has been shown in this study, that polycrystalline films with (111)-preferred orientation can be prepared at substrate temperatures as low as 250 C, as opposed to a report of optimum 600 C substrate temperature [1]. Thermal expansion mismatch between the film and substrate was found to have a substantial effect on the magnetic properties of the cobalt ferrite films, due to the large magnetoelastic coupling of cobalt ferrite. The growth of crystalline cobalt ferrite films at such low temperatures indicates the potential to use cobalt ferrite for MEMS devices and sensor applications [2] including integration with a wider range of multilayered device structures. This research was supported by the UK EPSRC (EP/D057094) and the US NSF (DMR-0402716). [1] J. Zhou et. al, Applied Surface Sciences, 253 (2007), p. 7456. [2] J. A. Paulsen et. al., Journal of Applied Physics, 97 (2005), p. 044502.

  17. Crystallographic properties of magnetron sputtered barium ferrite films

    Energy Technology Data Exchange (ETDEWEB)

    Capraro, S. [Laboratoire DIOM, University of Saint-Etienne, 23 rue Michelon, 42023 Saint-Etienne Cedex (France)]. E-mail: stephane.capraro@univ-st-etienne.fr; Berre, M. Le [LPM, UMR 5511, INSA Lyon, 7 av. Jean Capelle, 69621 Villeurbanne Cedex (France); Chatelon, J.P. [Laboratoire DIOM, University of Saint-Etienne, 23 rue Michelon, 42023 Saint-Etienne Cedex (France); Bayard, B. [Laboratoire DIOM, University of Saint-Etienne, 23 rue Michelon, 42023 Saint-Etienne Cedex (France); Joisten, H. [CEA-LETI, 17 rue des martyrs, 38041 Grenoble Cedex (France); Canut, C. [LPMCN, University Lyon I, 43 Bvd. du 11 novembre 1918, 69622 Villerbanne, Cedex (France); Barbier, D. [LPM, UMR 5511, INSA Lyon, 7 av. Jean Capelle, 69621 Villeurbanne Cedex (France); Rousseau, J.J. [Laboratoire DIOM, University of Saint-Etienne, 23 rue Michelon, 42023 Saint-Etienne Cedex (France)

    2004-09-15

    The development of devices combining a ferrite with a semiconductor chip is a major focus of current research. Barium hexaferrite (BaFe{sub 12}O{sub 19} or BaM) thick films are deposited here using a RF magnetron sputtering system. Films are amorphous and non magnetic after deposition. Post-deposition thermal annealing is employed to make the films crystallize. The effects of the substrate, thermal annealing process, thickness, substrate temperature on crystallographic properties and stoichiometry are studied using a X-ray diffractometry (XRD) and Rutherford back-scattering (RBS). The in-depth homogeneity of Ba, Fe and O is evaluated by secondary ion mass spectroscopy (SIMS). The study shows a good crystallization of BaM films and there is a preferential orientation among the crystallographic planes (1 0 1), (2 0 0), (2 0 3), (1 0 2), (1 1 0) and (2 0 5) when BaM films are prepared at low RF power and when the substrate is heated. For several elaboration parameters, grains size is in the range of 25 and 40 nm and BaM films are stoichiometric with regard to the target stoichiometry.

  18. Preparation and characterization of rice husk/ferrite composites

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A novel ferrite composite using rice husk as substrate has been prepared via high temperature treatment under nitrogen atmosphere.The rice husk substrate consists of porous activated carbon and silica,where spinel ferrite particles with average diameter of 59 nm are distributed.The surface area of the composite is greater than 170 m~2 g~(-1) and the bulk density is less than 0.6 g cm~(-3).Inert atmosphere is indispensable for the synthesis of pure ferrite composites,while different preparation temperatur...

  19. Corrosion behavior of magnetic ferrite coating prepared by plasma spraying

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yi; Wei, Shicheng, E-mail: wsc33333@163.com; Tong, Hui; Tian, Haoliang; Liu, Ming; Xu, Binshi

    2014-12-15

    Graphical abstract: The saturation magnetization (M{sub s}) of the ferrite coating is 34.417 emu/g while the M{sub s} value of the ferrite powder is 71.916 emu/g. It can be seen that plasma spray process causes deterioration of the room temperature soft magnetic properties. - Highlights: • Spinel ferrite coatings have been prepared by plasma spraying. • The coating consists of nanocrystalline grains. • The saturation magnetization of the ferrite coating is 34.417 emu/g. • Corrosion behavior of the ferrite coating was examined in NaCl solution. - Abstract: In this study, spray dried spinel ferrite powders were deposited on the surface of mild steel substrate through plasma spraying. The structure and morphological studies on the ferrite coatings were carried out using X-ray diffraction, scanning electron microscope and Raman spectroscopy. It was showed that spray dried process was an effective method to prepare thermal spraying powders. The coating showed spinel structure with a second phase of LaFeO{sub 3}. The magnetic property of the ferrite samples were measured by vibrating sample magnetometer. The saturation magnetization (M{sub s}) of the ferrite coating was 34.417 emu/g. The corrosion behavior of coating samples was examined by electrochemical impedance spectroscopy. EIS diagrams showed three corrosion processes as the coating immersed in 3.5 wt.% NaCl solution. The results suggested that plasma spraying was a promising technology for the production of magnetic ferrite coatings.

  20. Sol-gel preparation of La-doped bismuth ferrite thin film and its low-temperature ferromagnetic and ferroelectric properties

    Institute of Scientific and Technical Information of China (English)

    YAN Fuxue; ZHAO Gaoyang; SONG Na

    2013-01-01

    Bi0.85La0.15FeO3 thin film was prepared on ATO glass substrates by sol-gel technique.The effect of La doping on phase structure,film surface quality,ion valence,and ferroelectric/magnetic properties of Bi0.85La0.15FeO3 film were investigated.La doping suppressed the formation of impurity phases and the transition of Fe3+ to Fe2+ ions at room temperature.Compared with the un-doped BiFeO3,La-doping also increased the average grain size and the film density,which resulted in the decrease of film leakage current density.The remanent polarization and saturation magnetization were enhanced significantly by La doping.The remanent polarization of Bi0.85La0.15FeO3 films gradually decreased while saturation magnetization increased with the decrcase of measuring temperature within a range from 50 to 300 K.

  1. Chlorine gas sensing performance of palladium doped nickel ferrite thin films

    Science.gov (United States)

    Rao, Pratibha; Godbole, R. V.; Bhagwat, Sunita

    2016-05-01

    NiFe2O4 and Pd:NiFe2O4 (Pd=1 w/o, 3 w/o and 5 w/o) thin films, p-type semiconducting oxides with an inverse spinel structure have been used as a gas sensor to detect chlorine. These films were prepared by spray pyrolysis technique and XRD was used to confirm the structure. The surface morphology was studied using SEM. Magnetization measurements were carried out at room temperature using SQUID VSM, which shows ferrimagnetic behavior of the samples. The reduction in optimum operating temperature and enhancement in response was observed on Pd-incorporation in nickel ferrite thin films. Faster response and recovery characteristic is observed Pd-incorporated nickel ferrite thin films. The long-term stability is evaluated over a period of six months. This feature may be regarded as a significant facet towards their practical application as gas sensors.

  2. Defect induced modification of structural, topographical and magnetic properties of zinc ferrite thin films by swift heavy ion irradiation

    Science.gov (United States)

    Raghavan, Lisha; Joy, P. A.; Vijaykumar, B. Varma; Ramanujan, R. V.; Anantharaman, M. R.

    2017-04-01

    Swift heavy ion irradiation provides unique ways to modify physical and chemical properties of materials. In ferrites, the magnetic properties can change significantly as a result of swift heavy ion irradiation. Zinc ferrite is an antiferromagnet with a Neel temperature of 10 K and exhibits anomalous magnetic properties in the nano regime. Ion irradiation can cause amorphisation of zinc ferrite thin films; thus the role of crystallinity on magnetic properties can be examined. The influence of surface topography in these thin films can also be studied. Zinc ferrite thin films, of thickness 320 nm, prepared by RF sputtering were irradiated with 100 MeV Ag ions. Structural characterization showed amorphisation and subsequent reduction in particle size. The change in magnetic properties due to irradiation was correlated with structural and topographical effects of ion irradiation. A rough estimation of ion track radius is done from the magnetic studies.

  3. Dielectric properties of cobalt ferrite nanoparticles in ultrathin nanocomposite films.

    Science.gov (United States)

    Alcantara, Gustavo B; Paterno, Leonardo G; Fonseca, Fernando J; Pereira-da-Silva, Marcelo A; Morais, Paulo C; Soler, Maria A G

    2013-12-07

    Multilayered nanocomposite films (thickness 50-90 nm) of cobalt ferrite nanoparticles (np-CoFe2O4, 18 nm) were deposited on top of interdigitated microelectrodes by the layer-by-layer technique in order to study their dielectric properties. For that purpose, two different types of nanocomposite films were prepared by assembling np-CoFe2O4 either with poly(3,4-ethylenedioxy thiophene):poly(styrene sulfonic acid) or with polyaniline and sulfonated lignin. Despite the different film architectures, the morphology of both was dominated by densely-packed layers of nanoparticles surrounded by polyelectrolytes. The dominant effect of np-CoFe2O4 was also observed after impedance spectroscopy measurements, which revealed that dielectric behavior of the nanocomposites was largely influenced by the charge transport across nanoparticle-polyelectrolyte interfaces. For example, nanocomposites containing np-CoFe2O4 exhibited a single low-frequency relaxation process, with time constants exceeding 15 ms. At 1 kHz, the dielectric constant and the dissipation factor (tan δ) of these nanocomposites were 15 and 0.15, respectively. These values are substantially inferior to those reported for pressed pellets made exclusively of similar nanoparticles. Impedance data were further fitted with equivalent circuit models from which individual contributions of particle's bulk and interfaces to the charge transport within the nanocomposites could be evaluated. The present study evidences that such nanocomposites display a dielectric behavior dissimilar from that exhibited by their individual counterparts much likely due to enlarged nanoparticle-polyelectrolyte interfaces.

  4. Exotic thin films made from cobalt ferrite

    NARCIS (Netherlands)

    Lisfi, A.; Lisfi, A.; Williams, C.M.; Johnson, A.; Chang, P.; Corcoran, H.; Nguyen, L.T.; Lodder, J.C.; Morgan, W.; Soohoo, R.F.

    2005-01-01

    Epitaxial CoFe2O4 thin films have been grown by PLD on (100) MgO substrate. Two types of spin-reorientation have been observed in such films upon annealing or increasing the film-thickness. In the as-deposited layers and at low thickness the easy axis is confined to the normal to the film plane

  5. Preparation of Rare-Earth Composite Ferrite Magnetic Fluid

    Institute of Scientific and Technical Information of China (English)

    蒋荣立; 刘永超; 刘守坤; 鞠明礼

    2004-01-01

    Water-based rare-earth ferrite (RexFe3-xO4)magnetic fluids were prepared by chemical co-precipitation method. The result shows that saturation magnetic intensity of ferrite magnetic fluids can be improved by adding Dy3+ and the saturation magnetic intensity will reach the highest if n(Fe)∶n(Dy3+)=30∶1. The modification and formation mechanism of RexFe3-xO4 particles is discussed in detail. The physicochemical properties are investigated by the Gouy magnetic balance, IR, TEM, XRD, and EDX, etc.

  6. Effect of preparation conditions on physicochemical, surface and catalytic properties of cobalt ferrite prepared by coprecipitation

    Energy Technology Data Exchange (ETDEWEB)

    El-Shobaky, G.A., E-mail: elshobaky@yahoo.co [Physical Chemistry Department, National Research Center, Dokki, Cairo (Egypt); Turky, A.M.; Mostafa, N.Y.; Mohamed, S.K. [Chemistry Department, Faculty of Science, Suez Canal University, Ismailia 41522 (Egypt)

    2010-03-18

    Cobalt ferrite nanoparticles were prepared via thermal treatment of cobalt-iron mixed hydroxides at 400-600 {sup o}C. The mixed hydroxides were coprecipitated from their nitrates solutions using NaOH as precipitating agent. The effects of pH and temperature of coprecipitation and calcination temperature on the physicochemical, surface and catalytic properties of the prepared ferrites were studied. The prepared systems were characterized using TG, DTG, DTA, chemical analysis, atomic absorption spectroscopy (AAS), X-ray diffraction (XRD), energy dispersive X-ray (EDX) as well as surface and texture properties based on nitrogen adsorption-desorption isotherms. The prepared cobalt ferrites were found to be mesoporous materials that have crystallite size ranges between 8 and 45 nm. The surface and catalytic properties of the produced ferrite phase were strongly dependent on coprecipitation conditions of the mixed hydroxides and on their calcination temperature.

  7. Thick barium ferrite films use for passive isolators

    Energy Technology Data Exchange (ETDEWEB)

    Capraro, Stephane; Chatelon, Jean Pierre; Rouiller, Thomas; Rousseau, Jean Jacques [DIOM, University of Saint-Etienne, 23 rue Michelon, 42023 Saint-Etienne cedex (France); Berre, Martine Le; Barbier, Daniel [LPM, UMR 5511, INSA Lyon, 7 av. Jean Capelle, 69621 Villeurbanne cedex (France); Joisten, Helene [CEA-LETI, 17 rue des martyrs, 38041 Grenoble cedex (France)

    2004-12-01

    Ferrites have magnetic properties suitable for electronic applications, especially in the microwave range (circulators and isolators). Hexagonal ferrite, such as barium ferrite, are of great interest for microwave device applications because of their large resistivity and high permeability at high frequencies. BaM films are deposited under optimized conditions by RF magnetron sputtering on alumina substrates. In order to crystallize the films that are amorphous after deposition, a post deposition annealing at 800 C is implemented. All samples present a good crystallization, a smooth surface and a good in-depth uniformity. The magnetic properties of BaM films show an optimized coercive force and saturation magnetization of 330 kA/m and 500 mT respectively. These values are close to that of the bulk BaM. Isolators are then realized and measured by a vector network analyzer and a probing system. Results on transmission coefficients show a non reciprocal effect, which reaches 8.3 dB/cm at 50 GHz. This proves that such a component behaves like an isolator in the 50 GHz band. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  8. Preparation of lanthanum ferrite powder at low temperature

    Energy Technology Data Exchange (ETDEWEB)

    Andoulsi, R.; Horchani-Naifer, K.; Ferid, M., E-mail: karima_horchani@yahoo.com [Physical Chemistry Laboratory of Mineral Materials and their Applications, Hammam-Lif (Tunisia)

    2012-01-15

    Single lanthanum ferrite phase was successfully prepared at low processing temperature using the polymerizable complex method. To implement this work, several techniques such as differential scanning calorimetry, X-ray diffraction, Fourier Transform Infrared Spectroscopy, scanning electron microscopy and BET surface area measurements were used. Throw the obtained results, it was shown that steps of preparing the powder precursor and temperature of its calcination are critical parameters for avoiding phase segregation and obtaining pure lanthanum ferrite compound. Thus, a single perovskite phase was obtained at 600 deg C. At this temperature, the powder was found to be fine and homogeneous with an average crystallite size of 13 nm and a specific surface area of 12.5 m{sup 2}.g{sup -1}. (author)

  9. Preparation and characterization of manganese ferrite-based magnetic liposomes for hyperthermia treatment of cancer

    Energy Technology Data Exchange (ETDEWEB)

    Pradhan, Pallab [School of Biosciences and Bioengineering, Mumbai (India); Giri, Jyotsnendu [Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology, Mumbai 400076 (India); Banerjee, Rinti [School of Biosciences and Bioengineering, Mumbai (India); Bellare, Jayesh [School of Biosciences and Bioengineering, Mumbai (India); Bahadur, Dhirendra [Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology, Mumbai 400076 (India)]. E-mail: dhirenb@iitb.ac.in

    2007-04-15

    Comparative evaluation of two different methods of magnetic liposomes preparation, namely thin film hydration (TFH) and double emulsion (DE) with different molar ratios of egg-phosphatidyl choline (egg-PC) and cholesterol using lauric acid coated manganese ferrite-based aqueous magnetic fluid, is reported. TFH was found to be a better method of encapsulation and TFH 2:1 (egg-PC: cholesterol) magnetic liposomes showed the highest encapsulation efficiency and comparable heating ability to that of magnetic fluids. Stealth TFH 2:1 magnetic liposomes containing DSPE-PEG{sub 2000} were three-fold more cytocompatible as compared to the magnetic fluid. Stealth TFH 2:1 manganese ferrite-based magnetic liposomes might be useful for hyperthermia treatment of cancer.

  10. Preparation and characterization of manganese ferrite-based magnetic liposomes for hyperthermia treatment of cancer

    Science.gov (United States)

    Pradhan, Pallab; Giri, Jyotsnendu; Banerjee, Rinti; Bellare, Jayesh; Bahadur, Dhirendra

    2007-04-01

    Comparative evaluation of two different methods of magnetic liposomes preparation, namely thin film hydration (TFH) and double emulsion (DE) with different molar ratios of egg-phosphatidyl choline (egg-PC) and cholesterol using lauric acid coated manganese ferrite-based aqueous magnetic fluid, is reported. TFH was found to be a better method of encapsulation and TFH 2:1 (egg-PC: cholesterol) magnetic liposomes showed the highest encapsulation efficiency and comparable heating ability to that of magnetic fluids. Stealth TFH 2:1 magnetic liposomes containing DSPE-PEG 2000 were three-fold more cytocompatible as compared to the magnetic fluid. Stealth TFH 2:1 manganese ferrite-based magnetic liposomes might be useful for hyperthermia treatment of cancer.

  11. Surface evolution of lanthanum strontium cobalt ferrite thin films at low temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Newby, D., E-mail: dnewby@bu.edu [Department of Physics, Boston University, 590 Commonwealth Avenue, Boston, MA 02215 (United States); Kuyyalil, J.; Laverock, J. [Department of Physics, Boston University, 590 Commonwealth Avenue, Boston, MA 02215 (United States); Ludwig, K.F. [Department of Physics, Boston University, 590 Commonwealth Avenue, Boston, MA 02215 (United States); Division of Materials Science and Engineering, Boston University, 15 St. Mary' s Street, Brookline, MA 02446 (United States); Yu, Y.; Davis, J. [Division of Materials Science and Engineering, Boston University, 15 St. Mary' s Street, Brookline, MA 02446 (United States); Gopalan, S.; Pal, U.B.; Basu, S. [Division of Materials Science and Engineering, Boston University, 15 St. Mary' s Street, Brookline, MA 02446 (United States); Department of Mechanical Engineering, Boston University, 110 Cummington Street, Boston, MA 02215 (United States); Smith, K.E. [Department of Physics, Boston University, 590 Commonwealth Avenue, Boston, MA 02215 (United States); Division of Materials Science and Engineering, Boston University, 15 St. Mary' s Street, Brookline, MA 02446 (United States); School of Chemical Sciences and The MacDiarmid Institute for Advanced Materials and Nanotechnology, The University of Auckland, Auckland 1142 (New Zealand)

    2015-08-31

    The ultra-high vacuum surface preparation of heteroepitaxial lanthanum strontium cobalt ferrite thin films has been studied using soft X-ray photoelectron spectroscopy. Specifically, the effect of annealing the films at low temperatures in low partial pressures of oxygen and argon has been investigated. We find that atmospheric surface carbon contamination of the films can be removed in select anneal temperature regimes in argon, but remains bound to the surface with oxygen annealing at any temperature. Irrespective of the gas used, an insulating phase transition occurs near 300 °C due to strontium segregation at the surface. The surface develops more insulating character if annealed with oxygen. Different species are proposed to be responsible for the discrepancy in insulating character.

  12. Low-temperature Spin Spray Deposited Ferrite/piezoelectric Thin Film Magnetoelectric Heterostructures with Strong Magnetoelectric Coupling

    Science.gov (United States)

    2014-01-08

    1ITLE AND SUBTITLE 5a CONTRACTNUMBER Low-temperature spin spray deposited ferrite /piezoelectric thin W911NF-09-l-0435 film magnetoelectric...ABSTRACT Low-temperature spin spray deposited ferrite /piezoelectric thin film magnetoelectric heterostructures with strong magnetoelectric coupling...energy dissipation, which can be readily integrated in different integrated circuits. Low-temperature spin spray deposited ferrite /pie Approved

  13. Spin-spray plating of spinel ferrite films on semiconductor substrates

    Science.gov (United States)

    Yoo, Kee C.; Talisa, Salvador H.

    1990-10-01

    The possibility of monolithic integration of microwave magnetic and semiconductor electronic components has been investigated by growing spinel ferrite films on GaAs and Si using the spin-spray plating (SSP) technique. Since film deposition by SSP is performed at temperatures as low as 100 C, this process facilitates deposition of ferrite material without any thermal deterioration of the underlying GaAs devices. This was demonstrated by depositing and patterning a Ni-Zn ferrite film on a portion of a GaAs wafer containing several MMIC circuits. X-ray diffraction analysis of SSP-grown ferrite films indicated that the films formed different crystallographic textures at different growth temperatures. To achieve the thicker films required for practical device applications, deposition of a 25-pm-thick Ni-Zn ferrite film was demonstrated by a multiple deposition method with intermediate drying processes. The magnetic properties of these films, measured by ferrpmagnetic resonance (FMR) , compared well to those of commercially available polycrystalline material. The electrical resistivity of the films varied as a function of their chemical composition. The dielectric loss tangent (tan 5) of the as-deposited film was observed to be greater than ten. However, the measured resistivity dependence of dielectric loss tangent showed that the dominant microwave loss mechanism was not due to conduction alone. Post-growth annealing experiments indicated that moisture in the films trapped during the SSP process caused high dielectric losses, and that annealing could reduce the loss tangent value.

  14. Science Letters:Preparation of high-permeability NiCuZn ferrite

    Institute of Scientific and Technical Information of China (English)

    HU Jun; YAN Mi

    2005-01-01

    Appropriate addition of CuO/V2O5 and the reduction of the granularity of the raw materials particle decrease the sintering temperature ofNiZn ferrite from 1200 ℃ to 930 ℃. Furthermore, the magnetic properties of the NiZn ferrite prepared at low temperature of 930 ℃ is superior to that of the NiZn ferrite prepared by sintering at high temperature of 1200 ℃ because the microstructure of the NiZn ferrite sintered at 930 ℃ is more uniform and compact than that of the NiZn ferrite sintered at 1200 ℃.The high permeability of 1700 and relative loss coefficient tanδ//μi of 9.0×10-6 at 100 kHz was achieved in the (Ni0.17Zn0.63Cu0.20)Fe1.915O4 ferrite.

  15. Nanocrystalline zinc ferrite films studied by magneto-optical spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Lišková-Jakubisová, E., E-mail: liskova@karlov.mff.cuni.cz; Višňovský, Š. [Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, Prague (Czech Republic); Široký, P.; Hrabovský, D.; Pištora, J. [Nanotechnology Center, VŠB-Technical University of Ostrava, 17. listopadu 15, 708 33 Ostrava-Poruba (Czech Republic); Sahoo, Subasa C. [Department of Physics, Central University of Kerala, Kasaragod, Kerala 671314 (India); Prasad, Shiva [Department of Physics, Indian Institute of Technology Bombay, Powai, Mumbai 400076 (India); Venkataramani, N. [Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Powai, Mumbai 400076 (India); Bohra, Murtaza [Okinawa Institute of Science and Technology Graduate University (OIST), Okinawa (Japan); Krishnan, R. [Groupe d' Etude de la Matière Condensée (GEMaC), CNRS-UVSQ, 45 Avenue des Etats-Unis, 78935 Versailles (France)

    2015-05-07

    Ferrimagnetic Zn-ferrite (ZnFe{sub 2}O{sub 4}) films can be grown with the ferromagnetic resonance linewidth of 40 Oe at 9.5 GHz without going through a high temperature processing. This presents interest for applications. The work deals with laser ablated ZnFe{sub 2}O{sub 4} films deposited at O{sub 2} pressure of 0.16 mbar onto fused quartz substrates. The films about 120 nm thick are nanocrystalline and their spontaneous magnetization, 4πM{sub s}, depends on the nanograin size, which is controlled by the substrate temperature (T{sub s}). At T{sub s} ≈ 350 °C, where the grain distribution peaks around ∼20–30 nm, the room temperature 4πM{sub s} reaches a maximum of ∼2.3 kG. The films were studied by magnetooptical polar Kerr effect (MOKE) spectroscopy at photon energies between 1 and 5 eV. The complementary characteristics were provided by spectral ellipsometry (SE). Both the SE and MOKE spectra confirmed ferrimagnetic ordering. The structural details correspond to those observed in MgFe{sub 2}O{sub 4} and Li{sub 0.5}Fe{sub 2.5}O{sub 4} spinels. SE experiments confirm the insulator behavior. The films display MOKE amplitudes somewhat reduced with respect to those in Li{sub 0.5}Fe{sub 2.5}O{sub 4} and MgFe{sub 2}O{sub 4} due to a lower degree of spinel inversion and nanocrystalline structure. The results indicate that the films are free of oxygen vacancies and Fe{sup 3+}-Fe{sup 2+} exchange.

  16. Preparation, characterization and photocatalytic properties of nanometer zinc ferrite

    Institute of Scientific and Technical Information of China (English)

    Xiaojun Guo; Youli Qi; Xien Li; Shengyin Li; Wu Yang; Jinzhang Gao

    2004-01-01

    A combustion synthesis method was adapted for the efficient preparation of pure zinc ferrite particles (ZnFe204). It is based on the exothermic reaction of the corresponding metal nitrates with a reducing agent, to produce extremely fine-grained ashes that readily convert into pure ZnFe2O4 with treating thermally. The composition and microstructure of the so-obtained samples were studied by XRD (X-ray powder diffraction), TEM (Transmission Electron Microscopy) and AFM (Atomic Force Microscopy). These results showed that the range of particle size of ZnFe2O4 is about 15-25 nm. Photocatalytic activities of nanometer ZnFe2O4 were also evaluated by degradation of the curcumin solution.

  17. Influence of Sn4+ on Structural and DC Electrical Resistivity of Ni-Zn Ferrite Thick Films

    Science.gov (United States)

    Dalawai, S. P.; Shinde, T. J.; Gadkari, A. B.; Tarwal, N. L.; Jang, J. H.; Vasambekar, P. N.

    2016-12-01

    Among the soft ferrites, Ni-Zn ferrite is one of the most versatile ceramic materials because of their important electrical and magnetic properties. These properties were improved by substituting Sn4+ in Ni-Zn ferrites with chemical composition of Ni x Zn1+y-x Fe2-2y Sn y O4 (x = 0, 0.2, 0.4, 0.6, 0.8, 1.0; y = 0.1, 0.2). To achieve homogenous ferrite powder at lower sintering temperature and smaller duration in nano-size form, the oxalate co-precipitation method was preferred as compared to other physical and chemical methods. Using this powder, ferrite thick films (FTFs) were prepared by the screen printing technique because of its low cost and easy use. To study structural behavior, the FTFs were characterized by different techniques. The x-ray diffraction and thermo-gravimetric and differential thermal analysis studies show the formation of cubic spinel structure and ferrite phase formation, respectively. There is no remarkable trend observed in lattice constants for the Sn4+ (y = 0.1)- and Sn4+ (y = 0.2)-substituted Ni-Zn ferrites. The bond lengths as well as ionic radii on the A-site of Ni-Zn-Sn ferrites were found to decrease with increasing nickel content. The bond length and ionic radii on the B-sites remained almost constant for Sn4+ (y = 0.1, 0.2)-substituted Ni-Zn ferrites. The energy dispersive x-ray analysis confirms the elemental analysis of FTFs. The Fourier transform infrared spectra show two major absorption bands near 400 cm-1 and 600 cm-1 corresponding to octahedral and tetrahedral sites, respectively, which also confirms the formation of the ferrites. The field emission scanning electron microscopy images shows that the particles are highly porous in nature and located in loosely packed agglomerates. The average particle size of the FTFs lies in the range 20-60 nm. Direct current (DC) resistivity of Ni-Zn-Sn FTFs shows the semiconductor nature. The DC resistivity of Ni-Zn-Sn0.2FTFs is lower than Ni-Zn-Sn0.1 FTFs. The DC resistivity is found to

  18. Influence of Sn4+ on Structural and DC Electrical Resistivity of Ni-Zn Ferrite Thick Films

    Science.gov (United States)

    Dalawai, S. P.; Shinde, T. J.; Gadkari, A. B.; Tarwal, N. L.; Jang, J. H.; Vasambekar, P. N.

    2017-03-01

    Among the soft ferrites, Ni-Zn ferrite is one of the most versatile ceramic materials because of their important electrical and magnetic properties. These properties were improved by substituting Sn4+ in Ni-Zn ferrites with chemical composition of Ni x Zn1+ y- x Fe2-2 y Sn y O4 ( x = 0, 0.2, 0.4, 0.6, 0.8, 1.0; y = 0.1, 0.2). To achieve homogenous ferrite powder at lower sintering temperature and smaller duration in nano-size form, the oxalate co-precipitation method was preferred as compared to other physical and chemical methods. Using this powder, ferrite thick films (FTFs) were prepared by the screen printing technique because of its low cost and easy use. To study structural behavior, the FTFs were characterized by different techniques. The x-ray diffraction and thermo-gravimetric and differential thermal analysis studies show the formation of cubic spinel structure and ferrite phase formation, respectively. There is no remarkable trend observed in lattice constants for the Sn4+ ( y = 0.1)- and Sn4+ ( y = 0.2)-substituted Ni-Zn ferrites. The bond lengths as well as ionic radii on the A-site of Ni-Zn-Sn ferrites were found to decrease with increasing nickel content. The bond length and ionic radii on the B-sites remained almost constant for Sn4+ ( y = 0.1, 0.2)-substituted Ni-Zn ferrites. The energy dispersive x-ray analysis confirms the elemental analysis of FTFs. The Fourier transform infrared spectra show two major absorption bands near 400 cm-1 and 600 cm-1 corresponding to octahedral and tetrahedral sites, respectively, which also confirms the formation of the ferrites. The field emission scanning electron microscopy images shows that the particles are highly porous in nature and located in loosely packed agglomerates. The average particle size of the FTFs lies in the range 20-60 nm. Direct current (DC) resistivity of Ni-Zn-Sn FTFs shows the semiconductor nature. The DC resistivity of Ni-Zn-Sn0.2FTFs is lower than Ni-Zn-Sn0.1 FTFs. The DC resistivity is

  19. Exchange bias in zinc ferrite-FeNiMoB based metallic glass composite thin films

    Energy Technology Data Exchange (ETDEWEB)

    R, Lisha; P, Geetha; B, Aravind P.; Anantharaman, M. R., E-mail: mraiyer@yahoo.com [Cochin University of Science and Technology, Cochin-682022 (India); T, Hysen [Christian College, Chengannur, Kerala-689121 (India); Ojha, S.; Avasthi, D. K. [Inter University Accelerator Centre, Vasant Kunj, New Delhi-110067 (India); Ramanujan, R. V. [School of Materials Science and Engineering, Nanyang Technological University (Singapore)

    2015-06-24

    The Exchange bias phenomenon and methods to manipulate the bias field in a controlled manner are thrust areas in magnetism due to its sophisticated theoretical concepts as well as advanced technological utility in the field of spintronics. The Exchange bias effect is observed as a result of ferromagnetic-antiferromagnetic (FM-AFM) exchange interaction, usually observed as a loop shift on field cooling below the Neel temperature of AFM. In the present study, we have chosen zinc ferrite which is a well known antiferromagnet, and FeNiMoB based metallic glass as the ferromagnet. The films were prepared by RF sputtering technique. The thickness and composition was obtained by RBS. The magnetic studies using SQUID VSM indicate exchange bias effect in the system. The effect of thermal annealing on exchange bias effect was studied. The observed exchange bias in the zinc ferrite-FeNiMoB system is not due to FM-AFM coupling but due to spin glass-ferromagnetic interaction.

  20. Barium ferrite nanoparticles prepared by self-propagating low-temperature combustion method and its characterization

    Indian Academy of Sciences (India)

    P M Prithviraj Swamy; S Basavaraja; Vijayanand Havanoor; N V Srinivas Rao; R Nijagunappa; A Venkataraman

    2011-12-01

    The barium ferrite particles were prepared using a self-propagating low-temperature combustion method using polyethylene glycol (PEG) as a fuel. The process was investigated with simultaneous thermogravimetric-differential thermal analysis (TG–DTA). The crystalline structure, morphology and the magnetic properties of the barium ferrite particles were studied by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and SQUID susceptometer. The results show that the ignition temperature of PEG is lower compared with other combustion methods and gives nanocrystalline barium ferrite.

  1. Preparation, characterization and application of nanosized copper ferrite photocatalysts for dye degradation under UV irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Zaharieva, Katerina, E-mail: zaharieva@ic.bas.bg [Institute of Catalysis, Bulgarian Academy of Sciences, Acad. G. Bonchev St., Block 11, 1113 Sofia (Bulgaria); Rives, Vicente, E-mail: vrives@usal.es [GIR-QUESCAT, Dpto. Química Inorgánica, Universidad de Salamanca, 37008 Salamanca (Spain); Tsvetkov, Martin, E-mail: mptsvetkov@gmail.com [Faculty of Chemistry and Pharmacy, St. Kliment Ohridski University of Sofia, 1 J. Bourchier Blvd., 1164 Sofia (Bulgaria); Cherkezova-Zheleva, Zara, E-mail: zzhel@ic.bas.bg [Institute of Catalysis, Bulgarian Academy of Sciences, Acad. G. Bonchev St., Block 11, 1113 Sofia (Bulgaria); Kunev, Boris, E-mail: bkunev@ic.bas.bg [Institute of Catalysis, Bulgarian Academy of Sciences, Acad. G. Bonchev St., Block 11, 1113 Sofia (Bulgaria); Trujillano, Raquel, E-mail: rakel@usal.es [GIR-QUESCAT, Dpto. Química Inorgánica, Universidad de Salamanca, 37008 Salamanca (Spain); Mitov, Ivan, E-mail: mitov@ic.bas.bg [Institute of Catalysis, Bulgarian Academy of Sciences, Acad. G. Bonchev St., Block 11, 1113 Sofia (Bulgaria); Milanova, Maria, E-mail: nhmm@wmail.chem.uni-sofia.bg [Faculty of Chemistry and Pharmacy, St. Kliment Ohridski University of Sofia, 1 J. Bourchier Blvd., 1164 Sofia (Bulgaria)

    2015-06-15

    Nanosized copper ferrite-type materials (Cu{sub x}Fe{sub 3–x}O{sub 4}, 0 ≤ x ≤ 1) have been prepared by combination of co-precipitation and mechanochemical activation and/or thermal treatment. The crystalline structure and morphology of the obtained ferrite nanopowders have been characterized by different instrumental methods, such as Powder X-ray diffraction (PXRD), Mössbauer and FT-IR spectroscopies, specific surface area and porosity measurements, thermal analyses (Differential Thermal Analysis and Thermogravimetric Analysis) and Temperature-Programmed Reduction. The average crystallite size of copper ferrites ranged between 7.8 and 14.7 nm and show a superparamagnetic and collective magnetic excitations nature. The photocatalytic decolorization of Malachite green oxalate under different UV illumination intervals was examined using these copper ferrites as photocatalysts. The results indicate that the prepared nanostructured copper ferrites showed enhanced photocatalytic activity and amount adsorbed Malachite Green dye. The co-precipitated nanosized copper ferrite powder with a low content of copper metal ions in a magnetite host structure (Cu{sub 0.25}Fe{sub 2.75}O{sub 4}) showed an apparent pseudo-first-order rate constant 15.4 × 10{sup −3} min{sup −1} and an amount adsorbed Malachite Green as model organic dye pollutant per 1 g catalyst of 33.4 ppm/g after the dark period. The results confirm that the copper ferrites can be suitable for photocatalytic treatment of wastewaters containing organic dyes. The new aspect of presented investigations is to study the influence of different degree of incorporation of copper ions into the magnetite host structure and preparation methods on the photocatalytic properties of nanosized copper ferrite materials and obtaining of potential photocatalyst (Cu{sub 0.25}Fe{sub 2.75}O{sub 4}) with higher photocatalytic activity (15.4 × 10{sup −3} min{sup −1}) than that of the standard referent Degussa P25 (12 × 10

  2. Preparation and studies of Co(II) and Co(III)-substituted barium ferrite prepared by sol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Teh, Geok Bee [Department of Bioscience and Chemistry, Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, 53300 Kuala Lumpur (Malaysia)]. E-mail: tehgb@mail.utar.edu.my; Nagalingam, Saravanan [Department of Bioscience and Chemistry, Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, 53300 Kuala Lumpur (Malaysia); Jefferson, David A. [Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW (United Kingdom)

    2007-01-15

    The sol-gel preparative method was employed to synthesise Co(II) and Co(III)-substituted barium ferrite. This method was attempted to achieve higher homogeneity of the final product. Samples of substituted ferrites were characterised by various experimental techniques including high resolution transmission electron microscopy, X-ray diffraction analysis, magnetometry and thermal gravimetric analysis. The microstructural changes induced by such substitution are also discussed.

  3. Magnetic hyperthermia heating of cobalt ferrite nanoparticles prepared by low temperature ferrous sulfate based method

    Directory of Open Access Journals (Sweden)

    Tejabhiram Yadavalli

    2016-05-01

    Full Text Available A facile low temperature co-precipitation method for the synthesis of crystalline cobalt ferrite nanostructures using ferrous sulfate salt as the precursor has been discussed. The prepared samples were compared with nanoparticles prepared by conventional co-precipitation and hydrothermal methods using ferric nitrate as the precursor. X-ray diffraction studies confirmed the formation of cubic spinel cobalt ferrites when dried at 110 °C as opposed to conventional methods which required higher temperatures/pressure for the formation of the same. Field emission scanning electron microscope studies of these powders revealed the formation of nearly spherical nanostructures in the size range of 20-30 nm which were comparable to those prepared by conventional methods. Magnetic measurements confirmed the ferromagnetic nature of the cobalt ferrites with low magnetic remanance. Further magnetic hyperthermia studies of nanostructures prepared by low temperature method showed a rise in temperature to 50 °C in 600 s.

  4. Influence of preparation method on structural and magnetic properties of nickel ferrite nanoparticles

    Indian Academy of Sciences (India)

    Binu P Jacob; Ashok Kumar; R P Pant; Sukhvir Singh; E M Mohammed

    2011-12-01

    Nickel ferrite nanoparticles of very small size were prepared by sol–gel combustion and co-precipitation techniques. At the same annealing temperature sol–gel derived particles had bigger crystallite size. In both methods, crystallite size of the particles increased with annealing temperature. Sol–gel derived nickel ferrite particles were found to be of almost spherical shape and moderate particle size with a narrow size distribution; while co-precipitation derived particles had irregular shape and very small particle size with a wide size distribution. Nickel ferrite particles produced by sol–gel method exhibited more purity. Sol–gel synthesized nanoparticles were found to be of high saturation magnetization and hysteresis. Co-precipitation derived nickel ferrite particles, annealed at 400°C exhibited superparamagnetic nature with small saturation magnetization. Saturation magnetization increased with annealing temperature in both the methods. At the annealing temperature of 600°C, co-precipitation derived particles also became ferrimagnetic.

  5. Magnetic Properties of Ni-Zn Ferrite Prepared with the Layered Precursor Method

    Institute of Scientific and Technical Information of China (English)

    ZHOU Xin; HOU Zhi-Ling; LI Feng; QI Xin

    2010-01-01

    @@ We prepare NiZnFe2O4 soft magnetic ferrites with different molar ratios with the layered precursor method and investigate their magnetic properties.In the layered precursor,metal ions are scattered on the layer plate in a certain way on account of the effect of lowest lattice energy and lattice orientation.After high temperature calcinations,spinel ferrites with uniform structural component and single magnetic domain can be obtained,and the magnetic property is improved greatly.NiZnFe2O4 ferrites prepared have the best specific saturation magnetization of 79.15 emu.g-1,higher than that of 68 emu.g-1 prepared by the chemical co-precipitation method and that of 59 emu.g-1 prepared by the emulsion-gel method.Meanwhile the coercivity of NiZnFe2O4 ferrites prepared by layered precursor method is 14 kA.m-1,lower than that of 50emu.g-1 prepared by the co-precipitation method and that of 59 emu.g-1 prepared by the emulsion-gel method.

  6. Barium Ferrite Films Grown By Pulsed Laser Ablation

    NARCIS (Netherlands)

    Lisfi, A.; Lodder, J.C.; Haan, de P.; Roesthuis, F.J.G.

    1998-01-01

    Abstract available only. It is known that barium ferrite (BaFe12019) can grow with perpendicular anisotropy on A1203 a single crystal substrate,' but also on an amorphous substrate by using a ZnO buffer.2 Because of its large magnetic anisotropy which can easily overcome the shape anisotropy of the

  7. Structural and magnetic studies of Cr doped nickel ferrite thin films

    Energy Technology Data Exchange (ETDEWEB)

    Panwar, Kalpana, E-mail: kalpanapanwar99@gmail.com [Department of Pure & Applied Physics, University of Kota, Kota-324010 (India); Department of Physics, Govt. Women Engg. College, Ajmer-305002 (India); Heda, N. L. [Department of Pure & Applied Physics, University of Kota, Kota-324010 (India); Tiwari, Shailja [Department of Physics, Govt. Women Engg. College, Ajmer-305002 (India); Bapna, Komal; Ahuja, B. L. [Department of Physics, M. L. Sukhadia University, Udaipur-313001 (India); Choudhary, R. J.; Phase, D. M. [UGC-DAE Consortium for Scientific Research, University Campus, Indore-452017 (India)

    2016-05-23

    We have studied the structural and magnetic properties of Cr doped nickel ferrite thin films deposited on Si (100) and Si (111) using pulsed laser deposition technique. The films were deposited under vacuum and substrate temperature was kept at 700°C. X-ray diffraction analysis revealed that films on both substrates have single phase cubic spinel structure. However, the film grown on Si (111) shows better crystalline behavior. Fourier transform infrared spectroscopy suggests that films on both substrates have mixed spinel structure. These films show magnetic hysteresis behavior and magnetization value of film on Si (100) is larger than that on Si (111). It turns out that structural and magnetic properties of these two films are correlated.

  8. Preparation and Characterization of Nickel Ferrite-SiO2/Ag Core/Shell Nanocomposites

    Directory of Open Access Journals (Sweden)

    I. G. Blanco-Esqueda

    2015-01-01

    Full Text Available Magnetic composites with silver nanoparticles bonded to their surface were successfully prepared using a simple chemical method. By means of a sol-gel technique, nickel ferrite nanoparticles have been prepared and coated with silica to control and avoid their magnetic agglomeration. The structural and magnetic properties of the nanoparticles were studied in function of the annealing temperature. Then, silver nanoparticles were incorporated by hydrolysis-condensation of tetraethyl orthosilicate, which contains silver nitrate on the surface of the nickel ferrite-SiO2 core/shell. Samples were characterized using X-ray diffraction, IR spectroscopy, SEM, and magnetometry. Results show that the silica covered the nickel ferrite nanoparticles and the silver nanoparticles remain stable in the surface of the composite.

  9. Effect of PVP Additive on Properties of Cobalt Ferrite Nanoparticles Prepared by Hydrothermal Method

    Directory of Open Access Journals (Sweden)

    P. Razmjouee

    2015-05-01

    Full Text Available In this investigation, the effect of Polyvinylpyrrolidone (PVP additive on microstructure, morphology and magnetic properties of cobalt ferrite nanoparticles prepared by hydrothermal method was studied. X-ray diffraction (XRD studies in different synthesis conditions showed the formation of cobalt ferrite and cobalt oxide. Comparing IR spectrum of PVP additive, sol prepared before hydrothermal process and C-0.1PVP3, 190 obtained by FTIR spectroscopy indicated the formation of bond between PVP and surface of metallic hydroxide and cobalt ferrite particles, which prevented them from growing and coarsening. Scanning electron microscope (SEM was used to study the morphology of samples. According to vibration sample magnetometer (VSM results, as PVP amount increases from 0.1 to 0.3 volume percent, coercive field increases from 298 to 684 Oe and saturation magnetization decreases from 58 to 51 emu/g.

  10. Preparation and properties of nanosize MnZn ferrite from δ-FeOOH

    Institute of Scientific and Technical Information of China (English)

    HAO Shunli; WANG Xin; WEI Yu; Wang Yongming; Liu Chunjing

    2006-01-01

    Ferrous ion was transformed into feroxyhyte (δ-FeOOH) by oxidation. Then, manganese sulfate and zinc sulfate in some ratio were added to the feroxyhyte solution. The co-precipitation was boiling reflux conditions sometime under constant stirring. The nanosize MnZn ferrite powder was formed. The mechanism of preparation of the nanosize MnZn ferrite was discussed, and the formation of feroxyhyte which was playing a key role during the process was mentioned. The properties of powder was tested by means of X-ray diffraction, transmission electron microscopy and vibrating sample magnetometer. The results show that the samples of spherical particles about 20 nm, which have characteristics of ferrimagnetism, has larger saturation magnetization, but the remanent magnetization and coercivity are comparatively smaller. The spinel MnZn ferrite nanosize powder was successfully prepared from δ-FeOOH at low temperature, with low-carbon steel and peroxide as main material.

  11. Preparation of nanophase M-type ferrite and its laser-attenuated characteristics

    Institute of Scientific and Technical Information of China (English)

    LIU Xiang-cui; CHENG Xiang; ZHANG Liang; LIU Jian-hui; DU Gui-ping

    2011-01-01

    By citrate sol-gel auto-combustion method, the nanophase M-type planar hexagonal ferrite is prepared. The transmission electron microscopy (TEM), X-ray diffraction (XRD) and thermal analysis are used to study the grain size, phase composition,microstructure and crystallization process. The results show that the nanophase M-type Sr-ferrite prepared by this method is single, and its grain size is smaller than 100 nm. Moreover, most of the grains present hexagonal sheet shape. Tests are carried out for its attenuation to 1.06 μm laser. It is found that the extinction capability of the nanophase M-type Sr-ferrite smoke is good, and its mass extinction coefficient is 1.628 m2/g.

  12. Swift heavy ion induced surface modifications in nano-crystalline Li-Mg ferrite thin films

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Sanjukta [Institute of Physics, Sachivalaya Marg, Bhubaneswar 751005 (India) and Department of Physics, University of Calcutta, 92 A.P.C. Road, Kolkata 700009 (India)]. E-mail: sanjukta@iopb.res.in; Ganesan, V. [Inter University Consortium for DAE facilities, Khandwa Road, Indore 452017 (India); Khan, S.A. [Nuclear Science Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India); Ayyub, Pushan [Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005 (India); Kumar, Nitendar [Solid State Physics Laboratory, DRDO, Lucknow Road, Delhi 110054 (India)

    2006-09-30

    The swift heavy ion (190 MeV Au{sup 14+}) induced modifications in surface morphologies of the nanocrystals of ferrite thin films have been extensively studied through the images of atomic force microscopy (AFM). In most of the irradiated films significant features like, the ditch and dike structures, have been observed through out the surface. We try to explain the observed changes on the basis of thermal spike model followed by momentum transfer induced lateral mass transport. In addition to these changes some new and interesting features have been noticed after irradiation in 8F and 9F ferrite thin films. These new features are attributed to sputtering phenomenon due to the presence of defects like latent tracks.

  13. Structural and magnetic properties of cadmium substituted manganese ferrites prepared by hydrothermal route

    Energy Technology Data Exchange (ETDEWEB)

    Mostafa, Nasser Y., E-mail: nmost69@yahoo.com [Faculty of Science, Taif University, P.O. Box: 888, Al-Haweiah, Taif (Saudi Arabia); Chemistry Department, Faculty of Science, Suez Canal University, Ismailia 41522 (Egypt); Zaki, Z.I. [Faculty of Science, Taif University, P.O. Box: 888, Al-Haweiah, Taif (Saudi Arabia); Advanced Materials Division, Central Metallurgical R and D Institute (CMRDI), P.O. Box: 87 Helwan, Cairo (Egypt); Heiba, Z.K. [Faculty of Science, Taif University, P.O. Box: 888, Al-Haweiah, Taif (Saudi Arabia); Physics Department, Faculty of Science, Ain Shams University, Cairo (Egypt)

    2013-03-15

    Cd-substituted manganese ferrite Mn{sub 1-x}Cd{sub x}Fe{sub 2}O{sub 4} powders with x having values 0.0, 0.1, 0.3 and 0.5 have been synthesized by hydrothermal route at 180 Degree-Sign C in presence of NaOH as mineralizer. The obtained ferrite samples were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM) and vibrating sample magnetometer (VSM). The XRD analysis showed that pure single phases of cubic ferrites were obtained with x upto 0.3. However, sample with x{>=}0.5 showed hexagonal phase of cadmium hydroxide (Cd(OH){sub 2}) besides the ferrite phase. The increase in Cd-substitution upto x=0.3 leads to an increase in the lattice parameter as well as the average crystallite size of the prepared ferrites. The average crystallite size increased by increasing the Cd-content and was in the range of 39-57 nm. According to VSM results, the saturation magnetization increased with Cd ion substitution. - Highlights: Black-Right-Pointing-Pointer Hydrothermal synthesized of mono dispersed Cd-substituted MnFe{sub 2}O{sub 4} nanoparticles. Black-Right-Pointing-Pointer The change in Ms with increasing Cd-substitution was investigated Black-Right-Pointing-Pointer Pure single phases of cubic ferrites were obtained with x up to 0.3 Black-Right-Pointing-Pointer Sample with x{>=}0.5 showed hexagonal phase of Cd(OH){sub 2} beside the ferrite.

  14. Preparation and electrical properties of dense micro-cermets made of nickel ferrite and metallic copper

    Science.gov (United States)

    Baco-Carles, Valérie; Pasquet, Isabelle; Laurent, Véronique; Gabriel, Armand; Tailhades, Philippe

    2009-08-01

    Dense micro-cermets made of nickel ferrites and copper micrometric particles were obtained from partial reduction under hydrogenated atmosphere at 350 °C of mixed copper nickel ferrites, and sintering in nitrogen at 980 °C. The small copper particles are homogeneous in size and well dispersed in the spinel oxide matrix. No exudation of copper metal was observed after sintering. The micro-cermets prepared are semi-conducting materials with electrical conductivity lying from 44 to 130 S/cm at 980 °C. Their overall characteristics make them interesting for inert anodes dedicated to aluminium electrolysis in melted cryolite.

  15. High Coercivity Sr-ferrite Magnetic Thin Films Induced by Various Underlayers

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Three kinds of oxide underlayers, namely SiO2, ZnO and Al2O3, were deposited prior to the sputtering of Sr-ferrite films, respectively, in order to induce the optimum grain morphology and the texture of the films. A Sr-ferrite film with an easy axis in-plane orientation was induced by SiO2 underlayer. In contrast, it prefers to be perpendicular to film plane for the cases of ZnO and Al2O3 underlayers. The optimum magnetic properties of the former film along film plane are: 4πMr=1.7 kG, iHc=5.35 kOe, and Sq=0.59, which are mainly dominated by the exchange coupling effect, determined by Wohlfarth's remanence analysis, among grains. While those for the films with an easy axis perpendicular to film plane can be as high as 4πMr=3.72 kG, iHc=6.42 kOe, and Sq=0.82, which are mainly dominated by the magnetostatic interaction among grains.

  16. Adsorption of Pb(2+) from aqueous solution using spinel ferrite prepared from steel pickling sludge.

    Science.gov (United States)

    Fang, Binbin; Yan, Yubo; Yang, Yang; Wang, Fenglian; Chu, Zhen; Sun, Xiuyun; Li, Jiansheng; Wang, Lianjun

    2016-01-01

    In this paper, spinel ferrite with high crystallinity and high saturation magnetization was successfully prepared from steel pickling sludge by adding iron source and precipitator in the hydrothermal condition. The obtained spinel ferrite was characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), vibrating sample magnetometer (VSM), and Zeta potential methods and investigated as an adsorbent for removal of Pb(2+) from aqueous solution. Batch experiments were performed by varying the pH values, contact time, temperature and initial metal concentration. The result of pH impact showed that the adsorption of Pb(2+) was a pH dependent process, and the pH 5.8 ± 0.2 was found to be the optimum condition. The achieved experimental data were analyzed with various kinetic and isotherm models. The kinetic studies revealed that Pb(2+) adsorption onto spinel ferrite followed a pseudo-second order model, and the Langmuir isotherm model provided the perfect fit to the equilibrium experimental data. At different temperatures, the maximum Pb(2+) adsorption capacities calculated from the Langmuir equation were in the range of 126.5-175.4 mg/g, which can be in competition with other adsorbents. The thermodynamic results showed that the spinel ferrite could spontaneously and endothermically adsorb Pb(2+) from aqueous solution. The regeneration studies showed that spinel ferrite could be used five times (removal efficiency (%) >90%) by desorption with HNO3 reagent.

  17. Effect of quenching on the magnetic properties of Mg-ferrite thin films

    Directory of Open Access Journals (Sweden)

    Himadri Roy Dakua

    2016-05-01

    Full Text Available We have investigated the microstructural and magnetic properties of the post annealed slow cooled and quenched Mg-ferrite thin films. The microstructural properties of these films were studied through XRD, TEM and SEM. The magnetic properties were studied using VSM at 300K and 10K. The quenched film showed ∼1.66 times higher magnetization at room temperature (RT compared to the bulk and the slow cooled film (4πMS of bulk∼1880 Gauss at RT though the crystal phase, grain size and thickness of both the films were similar. The change in the cation distribution is the plausible origin of large magnetization observed in the quenched (rapid cooled film.

  18. The Preparation of Soft Magnetic Composites Based on FeSi and Ferrite Fibers

    Science.gov (United States)

    Strečková, Magdaléna; Fáberová, Mária; Bureš, Radovan; Kurek, Pavel

    2016-12-01

    The fields of soft magnetic composites and powder metallurgy technologies have a powerful potential to redesign the way of electric motor preparation, and will continue to grow for years to come. A design of the novel soft microcomposite material composed of spherical FeSi particles and Ni0.3Zn0.7Fe2O4 ferrite nanofibers is reported together with a characterization of basic mechanical and electrical properties. The needle-less electrospinning method was used for a preparation of Ni0.3Zn0.7Fe2O4 ferrite nanofibers, which has a spinel-type crystal structure as verified by XRD and TEM analysis. The dielectric coating was prepared by mixing of nanofibers with glycerol and ethanol because of safe manipulation with fumed fibers and homogeneous distribution of the coating around the FeSi particle surface. The final microcomposite samples were prepared by a combination of the traditional PM compaction technique supplemented with a conventional sintering process of the prepared green compacts. The composition and distribution of the secondary phase formed by the spinel ferrite fibers were examined by SEM. It is demonstrated that the prepared composite material has a tight arrangement without any significant porosity, which manifest itself through superior mechanical properties (high mechanical hardness, Young modulus, and transverse rupture strength) and specific electric resistivity compared to the related composite materials including resin as the organic binder.

  19. Effect of hydrothermal heat treatment on magnetic properties of copper zinc ferrite rf sputtered films

    Directory of Open Access Journals (Sweden)

    Jasmeet Kaur

    2016-05-01

    Full Text Available The hydrothermal treatment to the nano-structured films can overcome the destruction of the films. The Cu-Zn Ferrite films were fabricated by RF-sputtering on quartz substrates. Subsequently, the as deposited films were heat treated using hydrothermal process. The X-ray diffraction pattern of the as-deposited and hydrothermal treated films indicate nano-crystalline cubic spinel structure. The amorphous nature of the films is removed after hydrothermal treatment with decreased crystallite size. The field emission scanning electron micrographs showed merged columnar growth for as deposited films, which changes to well define columns after hydrothermal heating. The homogeneous cluster distribution is observed in surface view of the hydrothermal treated films. Hydrothermal treated films show merging of in-plane and out of plane magnetization plots (M(H whereas the M(H plots of as deposited films show angular dependence. The strong angular dependence is observed in the FMR spectra due to the presence of a uniaxial anisotropy in the films. The ferromagnetic interactions decrease in hydrothermal heated films due to the reduced shape anisotropy and crystallite size.

  20. Ferrite Film Loaded Frequency Selective Metamaterials for Sub-GHz Applications.

    Science.gov (United States)

    Gao, Bo; Yuen, Matthew M F; Ye, Terry

    2016-12-13

    Electromagnetic metamaterials are constructed with sub-wavelength structures that exhibit particular electromagnetic properties under a certain frequency range. Because the form-factor of the substructures has to be comparable to the wavelength of the operating frequency, few papers have discussed the metamaterials under GHz frequency. In this paper, we developed an innovative method to reduce the resonant frequency of metamaterals. By integrating the meta-structures with ferrite materials of higher permeability, the cell size of the meta-structure can be scaled down. This paper describes the methodology, design, and development of low-profile GHz ferrite loaded metamaterials. A ferrite film with a permeability of 20 could reduce the resonant frequency of metamaterials by up to 50%. A prototype has been fabricated and the measurement data align well with the simulation results. Because of the lowered operational frequency, the proposed ferrite loaded metamaterials offer more flexibility for various sub-GHz microwave applications, such as cloaks, absorbers, and frequency selective surfaces.

  1. Ferrite Film Loaded Frequency Selective Metamaterials for Sub-GHz Applications

    Directory of Open Access Journals (Sweden)

    Bo Gao

    2016-12-01

    Full Text Available Electromagnetic metamaterials are constructed with sub-wavelength structures that exhibit particular electromagnetic properties under a certain frequency range. Because the form-factor of the substructures has to be comparable to the wavelength of the operating frequency, few papers have discussed the metamaterials under GHz frequency. In this paper, we developed an innovative method to reduce the resonant frequency of metamaterals. By integrating the meta-structures with ferrite materials of higher permeability, the cell size of the meta-structure can be scaled down. This paper describes the methodology, design, and development of low-profile GHz ferrite loaded metamaterials. A ferrite film with a permeability of 20 could reduce the resonant frequency of metamaterials by up to 50%. A prototype has been fabricated and the measurement data align well with the simulation results. Because of the lowered operational frequency, the proposed ferrite loaded metamaterials offer more flexibility for various sub-GHz microwave applications, such as cloaks, absorbers, and frequency selective surfaces.

  2. Reorientation of magnetic anisotropy in epitaxial cobalt ferrite thin films

    NARCIS (Netherlands)

    Lisfi, A.; Williams, C.M.; Nguyen, L.T.; Lodder, J.C.; Coleman, A.; Corcoran, H.; Johnson, A.; Chang, P.; Kumar, A.; Morgan, W.

    2007-01-01

    Spin reorientation has been observed in CoFe2O4 thin single crystalline films epitaxially grown on (100) MgO substrate upon varying the film thickness. The critical thickness for such a spin-reorientation transition was estimated to be 300 nm. The reorientation is driven by a structural transition

  3. Reorientation of magnetic anisotropy in epitaxial cobalt ferrite thin films

    NARCIS (Netherlands)

    Lisfi, A.; Williams, C.M.; Nguyen, L.T.; Lodder, J.C.; Coleman, A.; Corcoran, H.; Johnson, A.; Chang, P.; Abhishek Kumar, A.K.; Kumar, A.; Morgan, W.

    2007-01-01

    Spin reorientation has been observed in CoFe2O4 thin single crystalline films epitaxially grown on (100) MgO substrate upon varying the film thickness. The critical thickness for such a spin-reorientation transition was estimated to be 300 nm. The reorientation is driven by a structural transition

  4. Method for preparing spherical ferrite beads and use thereof

    Science.gov (United States)

    Lauf, Robert J.; Anderson, Kimberly K.; Montgomery, Frederick C.; Collins, Jack L.

    2002-01-01

    The invention allows the fabrication of small, dense, highly polished spherical beads of hexagonal ferrites with selected compositions for use in nonreciprocal microwave and mm-wave devices as well as in microwave absorbent or reflective coatings, composites, and the like. A porous, generally spherical bead of hydrous iron oxide is made by a sol-gel process to form a substantially rigid bead having a generally fine crystallite size and correspondingly finely distributed internal porosity. The resulting gel bead is washed and hydrothermally reacted with a soluble alkaline earth salt (typically Ba or Sr) under conditions of elevated temperature and pressure to convert the bead into a mixed hydrous iron-alkaline earth oxide while retaining the generally spherical shape. This mixed oxide bead is then washed, dried, and calcined to produce the desired (BaFe.sub.12 O.sub.19 or SrFe.sub.12 O.sub.19) crystal structure. The calcined bead is then sintered to form a dense bead of the BaFe.sub.12 O.sub.19 and SrFe.sub.12 O.sub.19 phase suitable for polishing and incorporation into various microwave devices and components.

  5. Influnce of Stoichiometry and Molar Ratio of Barium Ferrite Thin Film Synthesized by Sol-gel on Alumina Substrate

    Institute of Scientific and Technical Information of China (English)

    AliGhasemi; M.R.Shams; A.Saatchi; M.Salehi; A.Hosseinpour

    2004-01-01

    Amorphous gels were processed with a varying Fe/Ba ratio of 11/5, 28/2, 10.5/1 in water and Solvent. Iron and barium nitrites with specific molar ratio was soloed in water and slovent at 60℃ for 3 hours untill a dark brown solution was prepared. The sols were introduced to substrate dropwise and spinning with 2000 rpm in 3 min was applied ; the work was repeated for 10 times and the samples were dried and sintered. The TGA analysis was used to identify the heating rate of the samples; at temperature of 1150℃ for one hour the final phase was attained, the thickness, uniformity, morphology and the composition were examined by SEM and XRD. The study shows that the fabrication barium ferrite film of the molar ratio of Fe/Ba=10.5/1 is much more suitable than other ratios.

  6. Influnce of Stoichiometry and Molar Ratio of Barium Ferrite Thin Film Synthesized by Sol-gel on Alumina Substrate

    Institute of Scientific and Technical Information of China (English)

    Ali Ghasemi; M.R. Shams; A.Saatchi; M.Salehi; A.Hosseinpour

    2004-01-01

    Amorphous gels were processed with a varying Fe/Ba ratio of 11/5, 28/2, 10.5/1 in water and Solvent. Iron and barium nitrites with specific molar ratio was solved in water and slovent at 60℃ for 3 hours untill a dark brown solution was prepared. The sols were introduced to substrate dropwise and spinning with 2000 rpm in 3 min was applied; the work was repeated for 10 times and the samples were dried and sintered. The TGA analysis was used to identify the heating rate of the samples; at temperature of 1150℃ for one hour the final phase was attained. the thickness, uniformity, morphology and the composition were examined by SEM and XRD. The study shows that the fabrication barium ferrite film of the molar ratio of Fe/Ba = 10.5/1 is much more suitable than other ratios.

  7. Preparation of Dysprosium Ferrite/Polyacrylamide Magnetic Composite Microsphere and Its Characterization

    Institute of Scientific and Technical Information of China (English)

    Hidehiro Kumazawa; Wang Zhifeng; Zhou Lanxiang; Zhang Hong; Li Yourong; Zhang Ming

    2005-01-01

    Using the technique of microemulsion polymerization with nano-reactor, dysprosium ferrite/polyacrylamide magnetic composite microsphere was prepared by one-step method in a single inverse microemulsion. The structure, average particle size, morphology of composite microsphere were characterized by FTIR, XRD, TEM and TGA. The magnetic responsibility of composite microsphere was also investigated. The results indicate that the magnetic composite microsphere possess high magnetic responsibility and suspension stability.

  8. Magnetic domain structure in nanocrystalline Ni-Zn-Co spinel ferrite thin films using off-axis electron holography

    Science.gov (United States)

    Zhang, D.; Ray, N. M.; Petuskey, W. T.; Smith, D. J.; McCartney, M. R.

    2014-08-01

    We report a study of the magnetic domain structure of nanocrystalline thin films of nickel-zinc ferrite. The ferrite films were synthesized using aqueous spin-spray coating at low temperature (˜90 °C) and showed high complex permeability in the GHz range. Electron microscopy and microanalysis revealed that the films consisted of columnar grains with uniform chemical composition. Off-axis electron holography combined with magnetic force microscopy indicated a multi-grain domain structure with in-plane magnetization. The correlation between the magnetic domain morphology and crystal structure is briefly discussed.

  9. Electromagnetic Wave Shieding Effectiveness of Carbon Fiber Sheet Coated Ferrite Film by Microwave-Hydrothermal Process

    Science.gov (United States)

    Murakami, Ri Ichi; Yamamoto, Hidetoshi; Kim, Chan Kong; Yim, Cheol Mun; Kim, Yun Hae

    The developments of electromagnetic wave shielding materials are strongly required because the malfunction of electronic equipment, mobile phone and wireless LAN avoids. In this study, it was investigated that the electromagnetic shielding effectiveness of carbon fiber sheets were enhanced by the ferrite which was coated by the microwave hydrothermal process. For coated carbon fiber sheet, the effects of ferrite and lamination of carbon fiber textile on the electromagnetic wave shielding effectiveness were discussed. In the range of frequency (100 1 GHz), the electromagnetic wave shielding effectiveness was measured by using TEM-Cell. The electromagnetic wave shielding effectiveness was greater for the coated carbon fiber sheets than for the uncoated carbon fiber sheets. When the insulation film was located between two carbon fiber sheets, the electromagnetic wave shielding effectiveness increased.

  10. Magnetic hysteresis of cerium doped bismuth ferrite thin films

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Surbhi [Department of Physics and Astrophysics, University of Delhi (India); Tomar, Monika [Physics Department, Miranda House, University of Delhi (India); Gupta, Vinay, E-mail: drguptavinay@gmail.com [Department of Physics and Astrophysics, University of Delhi (India)

    2015-03-15

    The influence of Cerium doping on the structural and magnetic properties of BiFeO{sub 3} thin films have been investigated. Rietveld refinement of X-ray diffraction data and successive de-convolution of Raman scattering spectra of Bi{sub 1−x}Ce{sub x}FeO{sub 3} (BCFO) thin films with x=0–0.20 reflect the single phase rhombohedral (R3c) formation for x<0.08, whereas concentration-driven gradual structural phase transition from rhombohedral (R3c) to partial tetragonal (P4mm) phase follows for x≥0.08. All low wavenumber Raman modes (<300 cm{sup −1}) showed a noticeable shift towards higher wavenumber with increase in doping concentration, except Raman E-1 mode (71 cm{sup −1}), shows a minor shift. Sudden evolution of Raman mode at 668 cm{sup −1}, manifested as A{sub 1}-tetragonal mode, accompanied by the shift to higher wavenumber with increase in doping concentration (x) affirm partial structural phase transition. Anomalous wasp waist shaped (M–H) hysteresis curves with improved saturation magnetization (M{sub s}) for BCFO thin films is attributed to antiferromagnetic interaction/hybridization between Ce 4f and Fe 3d electronic states. The contribution of both hard and soft phase to the total coercivity is calculated. Polycrystalline Bi{sub 0.88}Ce{sub 0.12}FeO{sub 3} thin film found to exhibit better magnetic properties with M{sub s}=15.9 emu/g without any impure phase. - Highlights: • Synthesis of single phase Bi{sub 1−x}Ce{sub x}FeO{sub 3} thin films with (x=0–0.2) on cost effective corning glass and silicon substrates using CSD technique. • Structural modification studies using Rietveld refinement of XRD and de-convolution of Raman spectra revealed partial phase transition from rhombohedral (R3c) to tetragonal (P4mm) phase. • Possible reasons for origin of pinched magnetic behavior of BCFO thin films are identified. • Contribution of both hard and soft magnetic phase in coercivity of BCFO thin films is calculated and practical

  11. Spin Seebeck effect in Y-type hexagonal ferrite thin films

    Science.gov (United States)

    Hirschner, J.; Maryško, M.; Hejtmánek, J.; Uhrecký, R.; Soroka, M.; Buršík, J.; Anadón, A.; Aguirre, M. H.; Knížek, K.

    2017-08-01

    The longitudinal spin Seebeck effect (SSE) has been investigated using Pt/ferrite bilayers employing two Y-hexagonal ferrites Ba2Zn2Fe12O22 (Zn2Y) and Ba2Co2Fe12O22 (Co2Y) deposited by a spin-coating method on SrTiO3(111 ) substrates. The prepared hexagonal ferrites are highly oriented with c axes perpendicular to the substrate plane. The room-temperature magnetic moments of both ferrimagnetic ferrites amount to similar values and, most importantly, both have easy magnetization normal to the c axis. Despite their similar magnetic response the notable SSE signal is only observed for Zn2Y whereas the SSE signal of Co2Y is below the experimental noise level. A plausible explanation for this surprising discrepancy is magnetic disorder induced by cobalt cations, the random distribution of which in the Co2Y ferrite structure might critically limit the spin-wave propagation. This results in suppression of the SSE signal in Co2Y, while the Zn2Y with nonmagnetic substituent exhibits significant SSE signal. The temperature dependence of SSE for Zn2Y was measured over the 30 -300 -K range and quantitatively analyzed considering the heat flow through the Pt/Zn2Y bilayer and thermal gradient across the Zn2Y thin layer as the most relevant parameters. Using this approach the normalized SSE smoothly increases with lowering temperature, which correlates to increasing magnon propagation length and magnetization with decreasing temperature.

  12. Preparation of lithium ferrite nanoparticles by high energy ball milling and characterizations

    Directory of Open Access Journals (Sweden)

    J. Touthang

    2016-11-01

    Full Text Available Ferrites are ferrimagnetic ceramic materials with inherent useful electromagnetic properties. Of them, spinelstructured ferrites are promising materials for microwave device applications; stress/torsion sensors and energy storage applications like anode materials in lithium batteries, fuel cells, solar cells etc. Nanostructured spinels further have high and wide scope of potential applications. In the present study, two different types of varied sized ferrimagnetic lithium ferrite spinel nanoparticles prepared using chemical sol-gel auto-combustion method were chosen. The prepared spinel particles were heated at 300°C for 1h. After heating the powders were milled using a High Energy Ball Mill for 30 minutes to further grind the particles and then subjected to various characterizations. Structural characterization was done using X-Ray Diffraction Method (XRD. The study revealed the spinel structure of these samples. Structural parameter such as lattice constant was determined using XRD data and found that the lattice parameter agrees with the standard data. DLS study found the agglomerations of the nanoparticles. The synthesized nanospinel particles were also characterized by the UVVis Spectroscopy, the Fourier Transform Infrared Spectroscopy (FTIR. Finally the magnetic hysteresis properties were studied using a Vibrating Sample Magnetometer (VSM.

  13. Preparation of Dy-ferrite Ferrofluids and Magnetochemical Studies on the Superparamagnetism

    Institute of Scientific and Technical Information of China (English)

    HU,Xian-Luo(胡先罗); XU,Chao(徐超); SHEN,Qin(沈骎); CHEN,Yi-Wei(陈奕卫); ZHAO,Hong(赵泓); ZHU,Chuan-Zheng(朱传征)

    2001-01-01

    This paper reports unprecedented preparation of Dy-ferrite water-based ferrofiuids stabilized by polymeric surfactant PMAA. The stability of ferrofluids was characterized in terms of the equation of criterion for the stability of ferrofluids. Magnetic susceptibility was measured with a Faraday-type magnetic balance at different temperature and with different magnetic field intensity. According to the Langevin function,superparamagtism of Dy-ferrite ferrofiuids has been confirmed by the curves of saturation magnetization σ versus H/T, and the blocking temperature is between 160 and 200 K.In terms of the simplified Langevin function in the low magnefic field, the average particle size is 20 nm that coincides with the result evaluated by FHMW. In addition, chemical analysis, infi-ared spect-a and Mosslauer spectroscopy were utilized to analyze the main components of the ferrofiuids.

  14. The Preparation and Investigation of Magnetic Properties of Magnesium Zinc ferrites

    Directory of Open Access Journals (Sweden)

    A. Rittidech

    2008-01-01

    Full Text Available Mg0.7Zn0.3Fe2O4 (MZF is a ferrites material, displaying interesting magnetic properties. It has a wide range of magnetic coils and electronic devices. In this research, MZF ceramics was prepared by solid state reaction route and interested on sintering temperature that have effective on phase formation of MZF, microstruce and magnetic properties. The phase identification of ceramic ferrites was performed using X-ray diffraction technique (XRD. It has been found that the dense of MZF ceramics were successfully obtained for sintering at 1300 oC. Moreover, the microstructure of MZF ceramics were examined by scanning electron microscopy (SEM and showed that the sizes of grain from 0.65-19.87 µm. The highly dense of MZF ceramics were obtained the magnetic permeability medium (µ as 14.38×10-14 N/A2.

  15. Experimental and Numerical Study on the Effect of ZDDP Films on Sticking During Hot Rolling of Ferritic Stainless Steel Strip

    Science.gov (United States)

    Hao, Liang; Jiang, Zhengyi; Wei, Dongbin; Gong, Dianyao; Cheng, Xiawei; Zhao, Jingwei; Luo, Suzhen; Jiang, Laizhu

    2016-10-01

    The aim of this study is to investigate the effect of zinc dialkyl dithio phosphate (ZDDP) films on sticking during hot rolling of a ferritic stainless steel strip. The surface characterization and crack propagation of the oxide scale are very important for understanding the mechanism of the sticking. The high-temperature oxidation of one typical ferritic stainless was conducted at 1373 K (1100 °C) for understanding its microstructure and surface morphology. Hot-rolling tests of a ferritic stainless steel strip show that no obvious cracks among the oxide scale were observed with the application of ZDDP. A finite element method model was constructed with taking into consideration different crack size ratios among the oxide scale, surface profile, and ZDDP films. The simulation results show that the width of the crack tends to be reduced with the introduction of ZDDP films, which is beneficial for improving sticking.

  16. Tailoring the optical bandgap and magnetization of cobalt ferrite thin films through controlled zinc doping

    Directory of Open Access Journals (Sweden)

    Deepanshu Sharma

    2016-08-01

    Full Text Available In this report, the tuning of the optical bandgap and saturation magnetization of cobalt ferrite (CFO thin films through low doping of zinc (Zn has been demonstrated. The Zn doped CFO thin films with doping concentrations (0 to 10% have been synthesized by ultrasonic assisted chemical vapour deposition technique. The optical bandgap varies from 1.48 to 1.88 eV and saturation magnetization varies from 142 to 221 emu/cc with the increase in the doping concentration and this change in the optical and magnetic properties is attributed to the change in the relative population of the Co2+ at the tetrahedral and octahedral sites. Raman study confirms the decrease in the population of Co2+ at tetrahedral sites with controlled Zn doping in CFO thin films. A quantitative analysis has been presented to explain the observed variation in the optical bandgap and saturation magnetization.

  17. Manganese ferrite prepared using reverse micelle process: Structural and magnetic properties characterization

    Energy Technology Data Exchange (ETDEWEB)

    Hashim, Mohd, E-mail: md.hashim09@gmail.com [Department of Physics, Aligarh Muslim University, Aligarh 202002 (India); Shirsath, Sagar E. [Spin Device Technology Centre, Department of Engineering, Shinshu University, Nagano 380-8553 (Japan); Meena, S.S. [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Mane, M.L. [Department of Physics, S.G.R.G. Shinde Mahavidyalaya, Paranda 413502, MS (India); Kumar, Shalendra [School of Materials Science and Engineering, Changwon National University, Changwon, Gyeongnam 641-773 (Korea, Republic of); Bhatt, Pramod [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Kumar, Ravi [Centre for Material Science Engineering, National Institute of Technology, Hamirpur, HP (India); Prasad, N.K.; Alla, S.K. [Deptartment of Metallurgical Engineering, Indian Institute of Technology (Banaras Hindu University), Varanasi 221005 (India); Shah, Jyoti; Kotnala, R.K. [National Physical Laboratory (CSIR), Dr. K.S. Krishnan Road, New Delhi 110012 (India); Mohammed, K.A. [Department of Mathematics & Physics Sciences, College of Arts and Sciences, University of Nizwa, Nizwa (Oman); Şentürk, Erdoğan [Department of Physics, Sakarya University, Esentepe, 54187 Sakarya (Turkey); Alimuddin [Department of Physics, Aligarh Muslim University, Aligarh 202002 (India)

    2015-09-05

    Highlights: • Preparation of Mn{sup 3+} substituted MnFe{sub 2}O{sub 4} ferrite by Reverse microemulsion process. • Characterization by XRD, SEM, VSM, Mössbauer spectroscopy and dielectric measurements techniques. • Magnetic properties of MnFe{sub 2}O{sub 4} enhanced after Mn{sup 3+} substitution. • The dielectric constant and ac conductivity increased with Mn{sup 3+} substitution. - Abstract: Reverse microemulsion process was employed to prepare of nanocrystalline Mn{sup 3+} substituted MnFe{sub 2−x}Mn{sub x}O{sub 4} ferrites. The structural, magnetic and dielectric properties were studied for different concentrations of Mn{sup 3+}. The structural and microstructural properties were analyzed using X-ray diffraction technique (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) spectroscopy techniques. The phase identification of the materials was studied by Rietveld refined XRD patterns which reveals single phase with cubic symmetry for the samples. The lattice parameters were ranged in between 8.369 and 8.379 Å and do not show any significant change with the substitution of Mn{sup 3+}. The average particles size was found to be around 11 ± 3 nm. Magnetization results obtained from the vibrating sample magnetometer (VSM) confirm that the substitution of Mn{sup 3+} in MnFe{sub 2}O{sub 4} ferrite caused an increase in the saturation magnetization and coercivity. The dependence of Mössbauer parameters on Mn{sup 3+} substitution has been analyzed. Magnetic behavior of the samples were also studied at field cooled (FC) and zero field cooled (ZFC) mode. The dependence of Mössbauer parameters on Mn{sup 3+} substitution was also analyzed. All the magnetic characterization shows that Mn{sup 3+} substitution enhance the magnetic behavior of MnFe{sub 2}O{sub 4} ferrite nanoparticles.

  18. Copper doped nickel ferrite nano-crystalline thin films: A potential gas sensor towards reducing gases

    Energy Technology Data Exchange (ETDEWEB)

    Rao, Pratibha; Godbole, R.V.; Bhagwat, Sunita, E-mail: smb.agc@gmail.com

    2016-03-01

    NiFe{sub 2}O{sub 4} and (1 wt% and 3 wt%) Cu:NiFe{sub 2}O{sub 4} thin films have been fabricated using spray pyrolysis deposition technique at 350 °C and then sintered at 650 °C for 3 h. X-ray diffraction, SEM, EDAX, UV-VIS spectroscopy, SQUID VSM were carried out to investigate phase formation, microstructural and influence of Cu doping on magnetic properties of NiFe{sub 2}O{sub 4} thin films. The gas response towards various gases viz. ethanol, Liquid Petroleum Gas (LPG), methanol and hydrogen sulfide (H{sub 2}S) is investigated. The results of XRD revealed that all samples had shown the principal phase of nickel ferrite and the lattice parameter was found to vary from 8.294 Å to 8.314 Å on an incorporation of Cu, and the crystalline sizes were about 40–45 nm. The effect of Cu concentration on saturation magnetization and coercive force were studied. The maximum value of saturation magnetization calculated from hysteresis loop was 89.16 emu/g at room temperature and 96.88 emu/g at 50 K. Cu content on the film surface was found to be maximum for 1 wt% Cu:NiFe{sub 2}O{sub 4} thin film and this film showed an improved response towards all gases. Response of ethanol for NiFe{sub 2}O{sub 4} thin film was found to be higher as compared to all the other gases. The lowering of the optimum operating temperature is observed in 1 wt% Cu:NiFe{sub 2}O{sub 4} thin film with higher selectivity towards ethanol than other gases. All results indicated that the Cu doping in nickel ferrite thin films has a significant influence on the properties. - Highlights: • Cu:NiFe{sub 2}O{sub 4} thin films are synthesized by low cost spray pyrolysis technique. • Addition of Cu content improves magnetic properties. • Cu content on the surface of the film enhances the gas response. • NiFe{sub 2}O{sub 4} thin films exhibit predominant selectivity towards ethanol. • 1 wt% Cu:NiFe{sub 2}O{sub 4} film responses towards ethanol at lower optimum temperature.

  19. Nanocrystalline magnesium ferrite prepared for photocatalytic applications by using the polymerized complex method

    Science.gov (United States)

    Dom, Rekha; Borse, Pramod H.; Hong, Kyong-Soo; Choi, Seyong; Lee, Byeong Seob; Ha, Myoung Gyu; Kim, Jong Pil; Jeong, Euh Duck; Kim, Hyun Gyu

    2015-11-01

    Magnesium ferrite (MgFe2O4) exhibiting a spinel phase was synthesized by using the polymerized complex and the solid-state reaction methods, and its physico-chemical properties were studied to explore the water-splitting under visible light photons. The study revealed the potential for using MgFe2O4 particles for photo-catalytic application. The structural study provided information on ferrite nano-crystallites fabricated by using the polymer complex method. The morphological studies demonstrated that, in contrast to the solid-state reaction method, a homogenous, monodispersed ferrite photocatalyst could be formed by using the polymerized complex method. The optical study revealed a larger visible-light absorption capability for the nanosized MgFe2O4 photocatalysts prepared by using the polymer complex methods, and indicated a red-shift of the bandgap by 0.06 eV as compared to the bandgap of the bulk. These nanocrystallites were highly photoactive with respect to the photodegradation and photocatalytic hydrogen evolution applications. The electrochemical analysis showed that they exhibited favorable bandedge positions suitable for photocatalytic H2 evolution. Thus, nanocrystalline MgFe2O4 is an active visible-light photocatalyst, that might be useful for the decomposition of water.

  20. Ferrite-Piezoelectric Layered Composites: Synthesis and Magnetoelectric Characterization

    Science.gov (United States)

    Hayes, R. W.; Srinivasan, G.

    2004-10-01

    The observation of strong magnetoelectric effects is reported in thick film bilayers and multilayers of ferrite-lead titanate zirconate (PZT). The ferrites used in our studies included pure and zinc substituted cobalt-, nickel- and lithium ferrites. Samples were prepared by sintering 10-40 mm thick films obtained by tape-casting. Measurements of ME voltage coefficients at 10-1000 Hz indicated a giant ME effect in nickel ferrite-PZT, but a relatively weak coupling in other ferrite-PZT systems. Evidence was found for enhancement in ME coefficients when Zn was substituted in ferrites. The Zn-assisted increase was attributed to low anisotropy and high permeability that resulted in favorable magneto-mechanical coupling in the composites. G. Srinivasan, E. T. Rasmussen, and R. Hayes, Phys. Rev. B 67, 014418 (2003) Supported by NSF and ARO grants.

  1. Self-organized single crystal mixed magnetite/cobalt ferrite films grown by infrared pulsed-laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Figuera, Juan de la, E-mail: juan.delafiguera@iqfr.csic.es [Instituto de Química Física “Rocasolano”, CSIC, Madrid E-28006 (Spain); Quesada, Adrián [Instituto de Cerámica y Vidrio, CSIC, Madrid E-28049 (Spain); Martín-García, Laura; Sanz, Mikel; Oujja, Mohamed; Rebollar, Esther; Castillejo, Marta [Instituto de Química Física “Rocasolano”, CSIC, Madrid E-28006 (Spain); Prieto, Pilar; Muñoz-Martín, Ángel [Universidad Autónoma de Madrid, E-28049 (Spain); Aballe, Lucía [Alba Synchrotron Light Facility, CELLS, Barcelona (Spain); Marco, José F. [Instituto de Química Física “Rocasolano”, CSIC, Madrid E-28006 (Spain)

    2015-12-30

    Highlights: • Infrared pulsed deposition is used to grow single crystal mixed magnetite-cobalt ferrite films. • Distinct topography with two mound types on the surface of the film. • Suggested origin of segregation into two phases is oxygen deficiency during growth. • Mössbauer is required to quantify the two components. - Abstract: We have grown mixed magnetite/cobalt ferrite epitaxial films on SrTiO{sub 3} by infrared pulsed-laser deposition. Diffraction experiments indicate epitaxial growth with a relaxed lattice spacing. The films are flat with two distinct island types: nanometric rectangular mounds in two perpendicular orientations, and larger square islands, attributed to the two main components of the film as determined by Mössbauer spectroscopy. The origin of the segregation is suggested to be the oxygen-deficiency during growth.

  2. Electron theory of perpendicular magnetic anisotropy of Co-ferrite thin films

    Directory of Open Access Journals (Sweden)

    Jun-ichiro Inoue

    2014-02-01

    Full Text Available We develop an electron theory for the t2g electrons of Co2+ ions to clarify the perpendicular magnetic anisotropy (PMA mechanism of Co-ferrite thin films by considering the spin-orbit interaction (SOI and crystal-field (CF potentials induced by the local symmetry around the Co ions and the global tetragonal symmetry of the film. Uniaxial and in-plane MA constants Ku and K1 at 0 K, respectively, are calculated for various values of SOI and CF. We show that reasonable parameter values explain the observed PMA and that the orbital moment for the in-plane magnetization reduces to nearly half of that of the out-of-plane magnetization.

  3. Electron theory of perpendicular magnetic anisotropy of Co-ferrite thin films

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Jun-ichiro; Yanagihara, Hideto; Kita, Eiji [Institute of Applied Physics, University of Tsukuba, Tsukuba 305-8573 (Japan); Niizeki, Tomohiko [Institute of Applied Physics, University of Tsukuba, Tsukuba 305-8573 (Japan); AIMR, Tohoku University, Sendai 980-8577 (Japan); Itoh, Hiroyoshi [Department of Pure and Applied Physics, Kansai University, Suita 564-8680 (Japan)

    2014-02-15

    We develop an electron theory for the t{sub 2g} electrons of Co{sup 2+} ions to clarify the perpendicular magnetic anisotropy (PMA) mechanism of Co-ferrite thin films by considering the spin-orbit interaction (SOI) and crystal-field (CF) potentials induced by the local symmetry around the Co ions and the global tetragonal symmetry of the film. Uniaxial and in-plane MA constants K{sub u} and K{sub 1} at 0 K, respectively, are calculated for various values of SOI and CF. We show that reasonable parameter values explain the observed PMA and that the orbital moment for the in-plane magnetization reduces to nearly half of that of the out-of-plane magnetization.

  4. Preparation of flat carbon support films

    NARCIS (Netherlands)

    Koning, RI; Oostergetel, GT; Brisson, A

    2003-01-01

    Wrinkling of carbon support films is known to limit the resolution of electron microscopy images of protein two-dimensional crystals. The origin of carbon wrinkling during preparation of the support films was investigated by reflected light microscopy. We observed that carbon films go through severa

  5. DC resistivity of Ni-Zn ferrites prepared by oxalate precipitation method

    Energy Technology Data Exchange (ETDEWEB)

    Shinde, T.J. [Department of Physics, K.R.P. Kanya Mahavidyalaya, Islampur 415409 (India)], E-mail: pshindetj@yahoo.co.in; Gadkari, A.B. [Department of Physics, G.K.G. College, Kolhapur 416004 (India); Vasambekar, P.N. [Department of Electronics, Shivaji University, Kolhapur 416004 (India)

    2008-09-15

    Polycrystalline ferrites with general formula Ni{sub 1-x}Zn{sub x}Fe{sub 2}O{sub 4} (x = 0, 0.2, 0.4, 0.6, 0.8, and 1.0) were prepared by oxalate precipitation method. The samples were characterized by X-ray diffraction (XRD), IR and scanning electron microscope (SEM) techniques. All compositions show cubic Spinel structure. Lattice constant increases with increase in zinc content, obeying Vegard's law. The physical densities are about 98.14% of their X-ray density. Average crystallite size lies in the range 27.59-31.49 nm. Infrared studies show two absorption bands near about 400 cm{sup -1} and 600 cm{sup -1} for octahedral and tetrahedral sites, respectively. The resistivity of all the samples was studied. It is observed that the resistivity of nickel-zinc ferrites prepared by oxalate precipitation method is higher than that prepared by ceramic and citrate precursor method. It is attributed to greater homogeneity and smaller grain size. Activation energy in paramagnetic region is higher than that of ferrimagnetic region.

  6. Structure and magnetic properties of highly textured nanocrystalline Mn–Zn ferrite thin film

    Energy Technology Data Exchange (ETDEWEB)

    Joseph, Jaison, E-mail: jaisonjosephp@gmail.com [Department of Physics, Goverment College, Khandola, Goa 403107 India (India); Tangsali, R.B. [Department of Physics, Goa University, Taleigao Plateau, Goa 403206 India (India); Pillai, V.P. Mahadevan [Department of Optoelectronics, University of Kerala,Thiruvananthapuram, Kerala 695581 India (India); Choudhary, R.J.; Phase, D.M.; Ganeshan, V. [UGC-DAE-CSR Indore, Madhya Pradesh 452017 India. (India)

    2015-01-01

    Nanoparticles of Mn{sub 0.2}Zn{sub 0.8}Fe{sub 2}O{sub 4} were chemically synthesized by co-precipitating the metal ions in aqueous solutions in a suitable alkaline medium. The identified XRD peaks confirm single phase spinal formation. The nanoparticle size authentication is carried out from XRD data using Debye Scherrer equation. Thin film fabricated from this nanomaterial by pulse laser deposition technique on quartz substrate was characterized using XRD and Raman spectroscopic techniques. XRD results revealed the formation of high degree of texture in the film. AFM analysis confirms nanogranular morphology and preferred directional growth. A high deposition pressure and the use of a laser plume confined to a small area for transportation of the target species created certain level of porosity in the deposited thin film. Magnetic property measurement of this highly textured nanocrystalline Mn–Zn ferrite thin film revealed enhancement in properties, which are explained on the basis of texture and surface features originated from film growth mechanism.

  7. Structural and magnetic properties of zinc ferrite thin films irradiated by 90 keV neon ions

    Energy Technology Data Exchange (ETDEWEB)

    Gafton, E.V., E-mail: elena.gafton@insp.jussieu.fr [Alexandru Ioan Cuza University, Faculty of Physics, 11 Carol I Blv., Iasi 700506 (Romania); Institut des NanoSciences de Paris, CNRS-UMR 7588, Sorbonne Universités, UPMC Univ Paris 06, 75005 Paris (France); Bulai, G., E-mail: georgiana.bulai@yahoo.com [Alexandru Ioan Cuza University, Faculty of Physics, 11 Carol I Blv., Iasi 700506 (Romania); Caltun, O.F., E-mail: caltun@uaic.ro [Alexandru Ioan Cuza University, Faculty of Physics, 11 Carol I Blv., Iasi 700506 (Romania); Cervera, S., E-mail: sophie.cervera@insp.jussieu.fr [Institut des NanoSciences de Paris, CNRS-UMR 7588, Sorbonne Universités, UPMC Univ Paris 06, 75005 Paris (France); Macé, S., E-mail: stephane.mace@insp.jussieu.fr [Institut des NanoSciences de Paris, CNRS-UMR 7588, Sorbonne Universités, UPMC Univ Paris 06, 75005 Paris (France); Trassinelli, M., E-mail: martino.trassinelli@insp.jussieu.fr [Institut des NanoSciences de Paris, CNRS-UMR 7588, Sorbonne Universités, UPMC Univ Paris 06, 75005 Paris (France); Steydli, S., E-mail: sebastien.steydli@insp.jussieu.fr [Institut des NanoSciences de Paris, CNRS-UMR 7588, Sorbonne Universités, UPMC Univ Paris 06, 75005 Paris (France); Vernhet, D., E-mail: dominique.vernhet@insp.jussieu.fr [Institut des NanoSciences de Paris, CNRS-UMR 7588, Sorbonne Universités, UPMC Univ Paris 06, 75005 Paris (France)

    2016-08-30

    Highlights: • Effect of different ion beam fluences on zinc ferrite thin films structure was investigated. • First reported results on zinc ferrite thin films irradiated with slow highly charged ions. • Increased magnetization was observed for samples irradiated even at low fluence. • Measurements of blocking temperature of thin films before and after irradiation. - Abstract: The effects of 90 keV neon beam irradiation on the structure and magnetic properties of zinc ferrite thin films have been investigated through several methods, namely, X-ray diffraction technique, Vibrating Sample and SQUID magnetometers. Beforehand, the pristine have also been characterized using profilometry and microscopy techniques. In particular single-phase formation of the thin films deposited on monocrystalline Si (111) substrate by pulsed laser deposition technique was confirmed. Crystal lattice, coercivity, saturation magnetization have been studied for the first time, as a function of ion penetration depth and irradiation fluence. The chemical composition and the crystallinity of the films are not affected with the ion impact acting as a mechanical stress relief. On the contrary, both magnetization and coercivity are sensitive to Ne{sup q+} ion irradiation and exhibit different behaviours depending on the ion fluence range.

  8. Modification of magnetic anisotropy induced by swift heavy ion irradiation in cobalt ferrite thin films

    Energy Technology Data Exchange (ETDEWEB)

    Nongjai, Razia [Department of Applied Physics, Zakir Hussain College of Engineering & Technology, A.M.U., Aligarh 202002 (India); Khan, Shakeel, E-mail: skhanapad@gmail.com [Department of Applied Physics, Zakir Hussain College of Engineering & Technology, A.M.U., Aligarh 202002 (India); Ahmed, Hilal; Khan, Imran [Department of Applied Physics, Zakir Hussain College of Engineering & Technology, A.M.U., Aligarh 202002 (India); Annapoorni, S. [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India); Gautam, Sanjeev [Advanced Analysis Center, Korea Institute of Science and Technology (KIST), Seoul 136-791 (Korea, Republic of); Lin, Hong-Ji; Chang, Fan-Hsiu [National Synchrotron Radiation Research Center (NSRRC), Hsinchu 30076, Taiwan (China); Hwa Chae, Keun [Advanced Analysis Center, Korea Institute of Science and Technology (KIST), Seoul 136-791 (Korea, Republic of); Asokan, K. [Material Science Division, Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India)

    2015-11-15

    The present study demonstrates the modification of magnetic anisotropy in cobalt ferrite (CoFe{sub 2}O{sub 4}) thin films induced by swift heavy ion irradiations of 200 MeV Ag-ion beams. The study reveals that both magnetizations and coercive field are sensitive to Ag-ions irradiation and to the fluences. The magnetic anisotropy enhanced at low fluence of Ag-ions due to domain wall pinning at defect sites created by ion bombardment and at high fluence, this magnetic anisotropy ceases and changes to isotropic behavior which is explained based on the significant structural and morphological changes. An X-ray absorption and x-ray magnetic circular dichroism studies confirms the inverse spinel structure of these compounds. - Highlights: • CoFe{sub 2}O{sub 4} thin films have been deposited on Silicon substrate by pulsed laser deposition technique. • Swift heavy ion irradiation of thin films at three different fluences. • Studied the structural and magnetic properties of the samples. • XRD and Raman studies indicate strain in the films. • Observed perpendicular magnetic anisotropy.

  9. Curie temperature and magnetic properties of aluminum doped barium ferrite particles prepared by ball mill method

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Daming [Center for Magnetism and Magnetic Nanostructures, University of Colorado at Colorado Springs, 1420 Austin Bluffs Pkwy, Colorado Springs, Colorado 80918 (United States); College of Materials and Chemical Engineering, Hainan University, Haikou 570228, Hainan (China); Harward, Ian; Baptist, Joshua; Goldman, Sara; Celinski, Zbigniew [Center for Magnetism and Magnetic Nanostructures, University of Colorado at Colorado Springs, 1420 Austin Bluffs Pkwy, Colorado Springs, Colorado 80918 (United States)

    2015-12-01

    Barium ferrite has attracted considerable interest in the fields of permanent magnets and perpendicular magnetic recording due to its strong uniaxial anisotropy and high Curie temperature (T{sub c}). We prepared aluminum doped barium ferrite ceramics (BaAl{sub x}Fe{sub 12−x}O{sub 19}, 0≤x≤6) by the ball mill method. The powder was milled for 96 h, and after forming pellets, annealed for 48 h in air at 1000 °C. The X-ray diffraction (XRD) data show that there are only single hexagonal phases in the samples without any impurity phase. The crystal lattice constants, a and c, were calculated by Cohen's method. Both a and c decrease with increasing x, ranging from 0.588 nm and 2.318 nm to 0.573 nm and 2.294 nm, respectively. A Vibrating Sample Magnetometer (VSM) and Superconducting Quantum Interference Device (SQUID) were used to investigate T{sub c} and magnetic properties of BaFe{sub 12−x}Al{sub x}O{sub 19}. It is found that T{sub c} decreases with increasing x, from 425 °C to 298 °C. It is also found that the saturated magnetization (4πM{sub s}) decreases with increasing x, while the coercivity (H{sub c}) increases with the increase in x. The anisotropy field was also determined from the SQUID measurement. - Highlights: • The Curie temperature and magnetic properties of aluminum doped barium ferrite particles were studied systemically. • The relation between 4πM{sub s} and composition x at 50 K (both experimental value and theoretical calculation) was revealed. • Occupation number for spin up and spin down as a function of temperature was shown. • The relation between 4πM{sub s} and composition x from 50 K to room temperature was revealed.

  10. Functional Ag porous films prepared by electrospinning

    Science.gov (United States)

    Dong, Guoping; Xiao, Xiudi; Liu, Xiaofeng; Qian, Bin; Liao, Yang; Wang, Chen; Chen, Danping; Qiu, Jianrong

    2009-06-01

    Face-centered cubic Ag porous films have been prepared directly from the heat treatment of AgNO 3-doped poly(vinyl alcohol) (PVA) electrospun nanofibers. Using Rhodamine B (RB) as the probing molecule, the surface-enhanced Raman scattering (SERS) effect of Ag porous films was demonstrated. The antibacterial activity of Ag porous films was also studied in this work. The propagation and biological activity of yeast cells were effectively inhibited by Ag porous films. These functional Ag porous films were expected to be applied in many fields, such as catalysis, diagnostics, sensors and antibacterial, etc.

  11. A Ceramic Thick Film Humidity Sensor Based on MnZn Ferrite

    Directory of Open Access Journals (Sweden)

    D. Egan

    2002-02-01

    Full Text Available A ceramic thick film humidity sensor, produced from MnZn ferrite, is presented. The proposed sensing mechanism is a combination of proton hopping, hydronium diffusion, and vacancy donor traps releasing electrons into the conduction band. The sensor structure comprises a two-layer device; the first layer is an interdigitated conductor and the second layer is a 30μm thick sensing layer. The effects of sintering the sensing pastes in air and vacuum have been reported. The air-fired sample exhibits the highest humidity sensitivity (1.54%/RH% and the lowest temperature sensitivity (0.37%/oC. The vacuum-fired sample has the lowest humidity sensitivity (0.043%/RH and the highest temperature sensitivity (0.77%/oC. The sensitivity results indicate that the air-fired sample has the best potential for use in humidity sensing applications.

  12. Curie temperature and magnetic properties of aluminum doped barium ferrite particles prepared by ball mill method

    Science.gov (United States)

    Chen, Daming; Harward, Ian; Baptist, Joshua; Goldman, Sara; Celinski, Zbigniew

    2015-12-01

    Barium ferrite has attracted considerable interest in the fields of permanent magnets and perpendicular magnetic recording due to its strong uniaxial anisotropy and high Curie temperature (Tc). We prepared aluminum doped barium ferrite ceramics (BaAlxFe12-xO19, 0≤x≤6) by the ball mill method. The powder was milled for 96 h, and after forming pellets, annealed for 48 h in air at 1000 °C. The X-ray diffraction (XRD) data show that there are only single hexagonal phases in the samples without any impurity phase. The crystal lattice constants, a and c, were calculated by Cohen's method. Both a and c decrease with increasing x, ranging from 0.588 nm and 2.318 nm to 0.573 nm and 2.294 nm, respectively. A Vibrating Sample Magnetometer (VSM) and Superconducting Quantum Interference Device (SQUID) were used to investigate Tc and magnetic properties of BaFe12-xAlxO19. It is found that Tc decreases with increasing x, from 425 °C to 298 °C. It is also found that the saturated magnetization (4πMs) decreases with increasing x, while the coercivity (Hc) increases with the increase in x. The anisotropy field was also determined from the SQUID measurement.

  13. Preparation and magnetic properties of nano size nickel ferrite particles using hydrothermal method

    Directory of Open Access Journals (Sweden)

    Nejati Kamellia

    2012-03-01

    Full Text Available Abstract Background Nickel ferrite, a kind of soft magnetic materials is one of the most attracting class of materials due to its interesting and important properties and has many technical applications, such as in catalysis, sensors and so on. In this paper the synthesis of NiFe2O4 nanoparticles by the hydrothermal method is reported and the inhibition of surfactant (Glycerol or Sodium dodecyl sulfate on the particles growth is investigated. Methods For investigation of the inhibition effect of surfactant on NiFe2O4 particles growth, the samples were prepared in presence of Glycerol and Sodium dodecyl sulfate. The X-ray powder diffraction (XRD, transmission electron microscopy (TEM, Fourier transform infrared spectroscopy (FT-IR, vibrating sample magnetometer (VSM and inductively coupled plasma atomic emission spectrometer (ICP-AES techniques were used to characterize the samples. Results The results of XRD and ICP-AES show that the products were pure NiFe2O4 and also nanoparticles grow with increasing the temperature, while surfactant prevents the particle growth under the same condition. The average particle size was determined from the Scherrer's equation and TEM micrographs and found to be in the range of 50-60 nm that decreased up to 10-15 nm in presence of surfactant. The FT-IR results show two absorption bands near to 603 and 490 cm-1 for the tetrahedral and octahedral sites respectively. Furthermore, the saturated magnetization and coercivity of NiFe2O4 nanoparticles were in the range of 39.60 emu/g and 15.67 Qe that decreased for samples prepared in presence of surfactant. As well as, the nanoparticles exhibited a superparamagnetic behavior at room temperature. Conclusions Nanosized nickel ferrite particles were synthesized with and without surfactant assisted hydrothermal methods. The results show that with increasing of temperature, the crystallinity of nanoparticles is increased. In the presence of surfactants, the crystallinity of

  14. Observation of longitudinal spin-Seebeck effect in cobalt-ferrite epitaxial thin films

    Science.gov (United States)

    Niizeki, Tomohiko; Kikkawa, Takashi; Uchida, Ken-ichi; Oka, Mineto; Suzuki, Kazuya Z.; Yanagihara, Hideto; Kita, Eiji; Saitoh, Eiji

    2015-05-01

    The longitudinal spin-Seebeck effect (LSSE) has been investigated in cobalt ferrite (CFO), an exceptionally hard magnetic spinel ferrite. A bilayer of a polycrystalline Pt and an epitaxially-strained CFO(110) exhibiting an in-plane uniaxial anisotropy was prepared by reactive rf sputtering technique. Thermally generated spin voltage in the CFO layer was measured via the inverse spin-Hall effect in the Pt layer. External-magnetic-field (H) dependence of the LSSE voltage (VLSSE) in the Pt/CFO(110) sample with H ∥ [001] was found to exhibit a hysteresis loop with a high squareness ratio and high coercivity, while that with H ∥ [ 1 1 ¯ 0 ] shows a nearly closed loop, reflecting the different anisotropies induced by the epitaxial strain. The magnitude of VLSSE has a linear relationship with the temperature difference (ΔT), giving the relatively large VLSSE /ΔT of about 3 μV/K for CFO(110) which was kept even at zero external field.

  15. Observation of longitudinal spin-Seebeck effect in cobalt-ferrite epitaxial thin films

    Energy Technology Data Exchange (ETDEWEB)

    Niizeki, Tomohiko, E-mail: t-niizeki@imr.tohoku.ac.jp [WPI Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Spin Quantum Rectification Project, ERATO, Japan Science and Technology Agency, Sendai 980-8577 (Japan); Kikkawa, Takashi [Spin Quantum Rectification Project, ERATO, Japan Science and Technology Agency, Sendai 980-8577 (Japan); Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Uchida, Ken-ichi, E-mail: kuchida@imr.tohoku.ac.jp [Spin Quantum Rectification Project, ERATO, Japan Science and Technology Agency, Sendai 980-8577 (Japan); Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012 (Japan); Oka, Mineto; Suzuki, Kazuya Z.; Yanagihara, Hideto; Kita, Eiji [Institute of Applied Physics, University of Tsukuba, Tsukuba 305-8573 (Japan); Saitoh, Eiji [WPI Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Spin Quantum Rectification Project, ERATO, Japan Science and Technology Agency, Sendai 980-8577 (Japan); Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Advanced Science Research Center, Japan Atomic Energy Agency, Tokai 319-1195 (Japan)

    2015-05-15

    The longitudinal spin-Seebeck effect (LSSE) has been investigated in cobalt ferrite (CFO), an exceptionally hard magnetic spinel ferrite. A bilayer of a polycrystalline Pt and an epitaxially-strained CFO(110) exhibiting an in-plane uniaxial anisotropy was prepared by reactive rf sputtering technique. Thermally generated spin voltage in the CFO layer was measured via the inverse spin-Hall effect in the Pt layer. External-magnetic-field (H) dependence of the LSSE voltage (V{sub LSSE}) in the Pt/CFO(110) sample with H ∥ [001] was found to exhibit a hysteresis loop with a high squareness ratio and high coercivity, while that with H∥[11{sup -}0] shows a nearly closed loop, reflecting the different anisotropies induced by the epitaxial strain. The magnitude of V{sub LSSE} has a linear relationship with the temperature difference (ΔT), giving the relatively large V{sub LSSE} /ΔT of about 3 μV/K for CFO(110) which was kept even at zero external field.

  16. Observation of longitudinal spin-Seebeck effect in cobalt-ferrite epitaxial thin films

    Directory of Open Access Journals (Sweden)

    Tomohiko Niizeki

    2015-05-01

    Full Text Available The longitudinal spin-Seebeck effect (LSSE has been investigated in cobalt ferrite (CFO, an exceptionally hard magnetic spinel ferrite. A bilayer of a polycrystalline Pt and an epitaxially-strained CFO(110 exhibiting an in-plane uniaxial anisotropy was prepared by reactive rf sputtering technique. Thermally generated spin voltage in the CFO layer was measured via the inverse spin-Hall effect in the Pt layer. External-magnetic-field (H dependence of the LSSE voltage (VLSSE in the Pt/CFO(110 sample with H ∥ [001] was found to exhibit a hysteresis loop with a high squareness ratio and high coercivity, while that with H ∥ [ 1 1 ̄ 0 ] shows a nearly closed loop, reflecting the different anisotropies induced by the epitaxial strain. The magnitude of VLSSE has a linear relationship with the temperature difference (ΔT, giving the relatively large VLSSE /ΔT of about 3 μV/K for CFO(110 which was kept even at zero external field.

  17. Nanostructure and magnetic properties of magnesium ferrite thin films deposited on glass substrate by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Arabi, H., E-mail: arabi-h@um.ac.ir [Magnetism and Superconducting Research Laboratory, Department of Physics, Faculty of Science, University of Birjand, Birjand (Iran, Islamic Republic of); Department of Physics, Faculty of Science, Ferdowsi University of Mashhad, Mashhad (Iran, Islamic Republic of); Khalili Moghadam, N. [Magnetism and Superconducting Research Laboratory, Department of Physics, Faculty of Science, University of Birjand, Birjand (Iran, Islamic Republic of)

    2013-06-15

    The spinel MgFe{sub 2}O{sub 4} thin films were prepared on the glass substrates at T{sub S}=400 °C by the spray pyrolysis deposition method. Structural and magnetic properties of the calcinated thin films at different temperatures were also investigated. By changing the calcination temperature from 400 to 600 °C, the crystallite size increased from 10 to 15 nm and the crystallinity of the films improved slightly. Thickness of the films calcinated at 400 and 600 °C were 0.648 and 1.473 μm respectively. However, the surface morphology of the films did not change considerably. Magnetic measurements, when the applied magnetic field was in parallel and perpendicular directions, showed the isotropic magnetic nature of the prepared films and their magnetic properties increased with the increment of calcination temperature. The H{sub c} value of thin films calcinated at 400 °C was about 168 Oe. - Highlights: ► Thin films of MgFe{sub 2}O{sub 4} are prepared via spray pyrolysis. ► All of the MgFe{sub 2}O{sub 4} films have nanostructure and the special magnetic properties. ► The surface morphology of films in different calcination temperatures is similar. ► The H{sub c} values of our films are independent of the applied field direction. ► The M{sub s} values in the plan and perpendicular directions are not the same.

  18. Effect of pH value on electromagnetic loss properties of Co–Zn ferrite prepared via coprecipitation method

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Xiaogu, E-mail: nthxg@126.com [School of Physics and Optoelectronic Engineering, Nanjing University of Information Science & Technology, Nanjing 210044 (China); School of Material Science and Engineering, Georgia Institute of Technology, Atlanta 30332 (United States); Zhang, Jing [Nanjing Center, China Geological Survey, Nanjing 210016 (China); Wang, Wei [School of Physics and Optoelectronic Engineering, Nanjing University of Information Science & Technology, Nanjing 210044 (China); Sang, Tianyi [Department of Electrical and Computer Engineering, University of California Davis, Davis 95616 (United States); Song, Bo [School of Material Science and Engineering, Georgia Institute of Technology, Atlanta 30332 (United States); Zhu, Hongli [Institute 53 of China North Industries Group Corporation, Jinan 250031 (China); Rao, Weifeng [School of Physics and Optoelectronic Engineering, Nanjing University of Information Science & Technology, Nanjing 210044 (China); Wong, Chingping [School of Material Science and Engineering, Georgia Institute of Technology, Atlanta 30332 (United States)

    2016-05-01

    In this paper, the cobalt zinc ferrite was prepared by coprecipitation method at different pH conditions. The influence of pH values on the coprecipitation reaction was theoretically analyzed at first. The calculated results showed that the pH values should be controlled in the range of 9–11 to form the stable precipitation. The XRD investigation was used to further confirm the formation of the composite on specific pH values. In addition, the morphological study revealed that the average particle size of the composite decreased from 40 nm to 30 nm when the pH value increased from 9–11. The variation of microstructure plays a critical role in controlling the electromagnetic properties. From the electromagnetic analysis, the dielectric loss factor was 0.02–0.07 and magnetic loss factor was 0.2–0.5 for the composite synthesized at pH of 9, which presents dramatically improved dielectric loss and magnetic loss properties than the samples prepared at pH of 10 and 11. The as-prepared cobalt zinc ferrite are highly promising to be used as microwave absorption materials. - Highlights: • Co–Zn ferrite was prepared by coprecipitation method with different pH values. • To obtain pure Co–Zn ferrite, the theoretical pH values were 9–11. • Microstructure and electromagnetic properties can be tuned by varying pH values. • Co–Zn ferrite prepared with pH=9 performed well electromagnetic loss properties.

  19. Magnetic studies of Li-Zn ferrites prepared by citrate precursor method

    Energy Technology Data Exchange (ETDEWEB)

    Soibam, Ibetombi, E-mail: ibetombi_phys@rediffmail.co [Department of Physics, Manipur University, Canchipur, Imphal 795 003 (India); Phanjoubam, Sumitra; Sharma, H.B.; Sarma, H.N.K. [Department of Physics, Manipur University, Canchipur, Imphal 795 003 (India); Prakash, C. [Directorate of ER and IPR, DRDO Bhawan, Rajaji Marg, New Delhi 110 011 (India)

    2009-11-15

    Ferrites having the general formula Li{sub 0.5-0.5x}Zn{sub x}Fe{sub 2.5-0.5x}O{sub 4} where 0<=x<=0.6 in steps of 0.2 were prepared by the citrate precursor method. The Curie temperature measured shows a decrease with increasing Zn concentration. Experimental results show that the room temperature initial permeability increases with the increase in the concentration of zinc. The initial permeability has also been studied as a function of frequency in the range of 100 Hz-1 MHz. The real part of initial permeability referred as initial permeability and the imaginary part of initial permeability better known as permeability loss show dispersion with frequency. Possible mechanism contributing to the above processes is discussed.

  20. Preparation and Characterization of M-Type Barium Ferrite Fibers via Aqueous Sol-Gel Process

    Institute of Scientific and Technical Information of China (English)

    GONG Cairong; FAN Guoliang; SONG Chonglin; L(U) Gang

    2007-01-01

    BaFe12O19 fibers was prepared via an aqueous sol-gel process using Fe(OH)( HCOO)2 synthesized in laboratory and Ba(CH3COO)2 as the original materials and citrate as the chelate. The rheological behaviour of spinnable sol was characterized on rheometer, and the development of gel fibers to barium ferrite fibers was studied by IR, TG and XRD. Morphology observation of the fibers was given on SEM, and the diameter of the obtained fibers was between 5 and 10 μm corresponding to different additives. The additives affected the surface tension of the precursor sol which had close relation to the microstructure of fibers. Sucrose and hydroxyethylic cellulose could improve the surface tension while diethanolamine and hexadecylamine reduce that of the precursor sol. And using diethanolamine or hexadecylamine as an additive, well-structured BaFe12O19 fibers could be obtained.

  1. Synthesis and magnetic investigation of cobalt ferrite nanoparticles prepared via a simple chemical precipitation method

    Directory of Open Access Journals (Sweden)

    Kambiz Hedayati

    2016-04-01

    Full Text Available In this research cobalt ferrite (CoFe2O4 nano-crystalline powders were prepared by simple chemical precipitation method using cobalt sulfate. The CoFe2O4 nanoparticles were characterized by X-ray diffraction, scanning electron microscopy  and Fourier transform infra-red spectroscopy. The crystallite size of CoFe2O4 nanoparticles was calculated by Debye–Scherrer formula. The effect of precursor, capping agent, temperature and concentration on the morphology and particle size of the products was investigated. Starch and gelatin as green, safe, water-soluble and cost-effective capping agents were used. Alternative gradient field magnetometer  confirms dominant influence of temperature on the morphology and magnetic domains. Results approve magnetic samples exhibit either ferromagnetic or super-paramagnetic behavior.

  2. Influence of the interface on the magnetic properties of NiZn ferrite thin films treated by proton irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, X.D. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000 (China); Guo, D.W. [Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000 (China); Zhang, C.H., E-mail: c.h.zhang@impcas.ac.cn [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Fan, X.L.; Chai, G.Z. [Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000 (China); Xue, D.S., E-mail: xueds@lzu.edu.cn [Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000 (China)

    2015-09-01

    In order to systematically investigate the influence of the interface on the magnetic properties, polycrystalline NiZn ferrite thin films were irradiated with 60 keV proton in the dose range from 5 × 10{sup 12} to 5 × 10{sup 16} ions/cm{sup 2}. A non-destructive approach by proton irradiation was found to finely adjust the magnetic properties of polycrystalline NiZn ferrite thin films such as coercivity, perpendicular magnetic anisotropy as well as the effective g value. The coercivity is about 725 Oe for high proton dose ferrite, which is twice larger than the unirradiated one. The ferromagnetic resonance measurements indicated that perpendicular magnetic anisotropy and the effective g value increase with the irradiation dose. Our finding indicates that all modifications of these magnetic properties were associated with the change of interface due to the diffusion and the stress induced by proton irradiation. The change of the effective g value is a result of lattice expansion and the decrease of the magnetic dipole interaction between the columnar grains. This work provides a feasible way to tailor the magnetic properties of thin films by ion irradiation and promotes investigations for the stability of magnetic thin film devices in space or unclear radiation environments.

  3. Mn-Zn ferrite nanoparticles for ferrofluid preparation: Study on thermal-magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Arulmurugan, R. [Department of Physics, Pondicherry Engineering College, Pondicherry 605014 (India)]. E-mail: arulphysics@rediffmail.com; Vaidyanathan, G. [Department of Physics, Pondicherry Engineering College, Pondicherry 605014 (India)]. E-mail: gvn_pec@yahoo.com; Sendhilnathan, S. [Department of Physics, Sri Manakula Vinayagar Engineering College, Pondicherry 605107 (India); Jeyadevan, B. [Graduate School of Environmental Studies, Tohoku University, Sendai 980-8579 (Japan)

    2006-03-15

    Mn{sub 1-x}Zn{sub x}Fe{sub 2}O{sub 4} (with x varying from 0.1 to 0.5) ferrite nanoparticles used for ferrofluid preparation have been prepared by chemical co-precipitation method and characterized. Characterization techniques like elemental analysis by atomic absorption spectroscopy and spectrophotometry, thermal analysis using simultaneous TG-DTA, XRD, TEM, VSM and Moessbauer spectroscopy have been utilized. The final cation contents estimated agree with the initial degree of substitution. The Curie temperature (T{sub c}) and particle size decrease with the increase in zinc substitution. In the case of particles with higher zinc concentration, both ferrimagnetic nanoparticles and particles exhibiting superparamagnetic behavior at room temperature are present. In addition, some of the results obtained by slightly altering the preparation condition are also discussed. The precipitated particles were used for ferrofluid preparation. The fine particles were suitably dispersed in heptane using oleic acid as the surfactant. The volatile nature of the carrier chosen helps in altering the number concentration of the magnetic particles in a ferrofluid. Magnetic properties of the fine particles and ferrofluids are discussed. Ferrofluids having Mn{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} particles can be used for the energy conversion application utilizing the magnetically induced convection for thermal dissipation.

  4. Effect of zinc doping on the structural and magnetic properties of nickel ferrite thin films fabricated by pulsed laser deposition technique

    Energy Technology Data Exchange (ETDEWEB)

    Raghavender, A.T., E-mail: raghavi9@gmail.com [Nanomagnetism Laboratory, Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of); Hoa Hong, Nguyen, E-mail: nguyenhong@snu.ac.kr [Nanomagnetism Laboratory, Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of); Chikoidze, Ekaterina; Dumont, Yves [Laboratoire GeMAC, UMR 8635 CNRS—Université de Versailles, 45 Avenue des Etats-Unis, 78035 Versailles Cedex (France); Kurisu, Makio [Department of Physics, Graduate School of Science and Engineering, Ehime University, Matsuyama 790-8577 (Japan)

    2015-03-15

    Zinc, as known as non-magnetic element, has been doped into nickel ferrite under thin film form to modify its structural and magnetic properties. Laser ablated Ni{sub 1−x}Zn{sub x}Fe{sub 2}O{sub 4} (0.0≤x≤0.5) thin films grown on R-cut Al{sub 2}O{sub 3} (0001) substrates using pulsed laser deposition (PLD) technique are single phase with (l l l) orientation, and they are strongly room temperature ferromagnetic. Compared to other Ni–Zn ferrite thin films we observed the enhancement in coercivity H{sub c}. Higher H{sub c} thin films can be used as potential candidates for modern miniaturization of electronic devices. - Highlights: • Laser ablated ferrite thin films. • Enhanced structural and magnetic properties of Ni–Zn ferrite thin films. • Ni–Zn Ferrite films are strongly room temperature ferromagnetic. • Higher coercivity in fabricated films.

  5. 电感器用Ni-Cu-Zn铁氧体薄膜的设计与性能研究%Design and Performance of Ni-Cu-Zn Ferrite Film for Inductor

    Institute of Scientific and Technical Information of China (English)

    范跃农; 冯则坤; 陈中艳; 龚荣洲

    2012-01-01

    Ni-Cu-Zn ferrite inductor film was fabricated by screen print technology, and its performances were in-vestigated. XRD results suggest that the as-prepared thin films exhibit the same crystalline structure. The results show that after introducing of ferrite film, the inductance increases by 30%, the quality factor is improved, and the resonance frequency decrease. Ferrite inductor thin films annealed at 400℃ exhibit an optimum performance with high quality at 50 MHz, inductance increased by 27%, the quality factor increased by 39%.%采用丝网印刷技术制备Ni-Cu-Zn铁氧体电感器薄膜,并对其性能进行了表征.XRD分析表明,铁氧体薄膜具有相同的晶格结构.研究结果表明,在引入了铁氧体薄膜后,电感器的电感量相对于空心电感器有30%左右的提高,品质因数依频率不同有所改善,共振频率有所降低,经400℃后处理的薄膜电感器在低频时性能最好,50 MHz时电感量提高了27%,品质因数提高了39%.

  6. Spin Hall magnetoresistance at the interface between platinum and cobalt ferrite thin films with large magnetic anisotropy

    Directory of Open Access Journals (Sweden)

    Takeshi Tainosho

    2017-05-01

    Full Text Available The recently discovered spin Hall magnetoresistance (SMR effect is a useful means to obtain information on the magnetization process at the interface between a nonmagnetic metal and ferromagnetic insulators. We report the SMR measurements at the interface between platinum and cobalt ferrite thin films for samples with two different preferential directions of magnetization (out-of-plane and in-plane. The directional difference of the magnetic easy axis does not seem to influence the value of SMR.

  7. Analysis of the broadband chaotic spin-wave excitations in an active ring oscillator based on a metalized ferrite film

    Science.gov (United States)

    Kondrashov, A. V.; Ustinov, A. B.; Kalinikos, B. A.; Demokritov, S. O.

    2016-11-01

    This paper reports the first experimental study of broadband chaotic nonlinear spin- wave excitations which is formed through development of four-wave parametric processes in active ring oscillator based on metallized ferrite film. We find that an increase in the oscillation power leads to Hopf bifurcations sequence. Monochromatic, periodic quasi-periodic and chaotic excitations are observed. Spectra of the chaotic excitations consist of series of chaotic bands separated well in frequency. Parameters of the chaotic attractors are discussed.

  8. Preparation and investigation of dc conductivity and relative permeability of epoxy/Li–Ni–Zn ferrite composites

    Energy Technology Data Exchange (ETDEWEB)

    Darwish, M.A., E-mail: Mostafa_ph@yahoo.com [Physics Department, Faculty of Science, Tanta University, Tanta (Egypt); Saafan, S.A.; El- Kony, D. [Physics Department, Faculty of Science, Tanta University, Tanta (Egypt); Salahuddin, N.A. [Chemistry Department, Faculty of Science, Tanta University, Tanta (Egypt)

    2015-07-01

    Ferrite nanoparticles – having the compositions Li{sub (x/2)}(Ni{sub 0.5}Zn{sub 0.5}){sub (1−x)}Fe{sub (2+x/2)}O{sub 4} (x=0, 0.2, 0.3) – have been prepared by the co-precipitation method. The prepared powders have been divided into groups and sintered at different temperatures (373 K, 1074 K and 1473 K). X-Ray diffraction analysis (XRD) for all samples has confirmed the formation of the desired ferrites with crystallite sizes within the nanoscale (<100 nm). The dc conductivity, the relative permeability and the magnetization of the ferrite samples have been investigated and according to the results, the sample Li{sub 0.15}(Ni{sub 0.5}Zn{sub 0.5}){sub 0.7} Fe{sub 2.15}O{sub 4} sintered at 1473 K has been chosen to prepare the composites. The particle size of this sample has been recalculated by using JEOL JEM-100SX transmission electron microscope and it has been found about 64.7 nm. Then, a pure epoxy sample and four pristine epoxy resin /Li{sub 0.15}(Ni{sub 0.5}Zn{sub 0.5}){sub 0.7} Fe{sub 2.15}O{sub 4} composites have been prepared using different ferrite contents (20%, 30%, 40%, and 50%) wt.%. These samples have been characterized by Fourier transform infrared (FTIR) spectroscopy and their dc conductivity, relative permeability and magnetization have also been investigated. The obtained results indicate that the investigated composites may be promising candidates for practical applications such as EMI suppressor and high frequency applications. - Highlights: • Li–Ni–Zn ferrites have been prepared by the chemical co-precipitation method. • Epoxy-ferrite composites have been prepared too. • Structural and magnetic properties of all prepared samples were investigated. • Results indicate that these composites may be promising for useful applications.

  9. Pr and Gd co-doped bismuth ferrite thin films with enhanced multiferroic properties

    Indian Academy of Sciences (India)

    Chang Chun Chen; Zi Xuan Liu; Gui Wang; Yi Lin Yan

    2014-12-01

    Pr and Gd co-modified Bi0.95−PrGd0.05FeO3 ( = 0.00, 0.05, 0.10) (BPGFO) thin films on Pt(111)/Ti/SiO2/Si(100) substrates were prepared by a sol-gel together with spin coating technique. A detailed study of electrical and magnetic properties of these thin films is reported. X-ray diffraction analysis shows that, with an increase in Pr content, the crystal structures of BPGFO thin films retain rhombohedral (R3c) symmetry accompanied by structure distortion. Polarization-electric field hysteresis loops of these thin films demonstrate that the incorporation of Pr and Gd into the Bi site of BiFeO3 thin film could enhance the ferroelectric performance. Compared to other thin films, the optimal ferroelectric behaviours in Bi0.85Pr0.1Gd0.05FeO3 thin film are ascribed to its large dielectric constant, low dissipation factor and low leakage current density. Room temperature magnetization-magnetic field curves of these thin films indicate that all the samples are of paramagnetic behaviours and the enhanced saturation magnetic properties can be found.

  10. Preparation and Properties of Polyaniline Composite Films

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qing-hua

    2002-01-01

    Polyaniline (PAn) was synthesized by chemical oxidation polymerization. The conductive polymer doped by camphor sulfonic acid (CSA) and a matrix polymer,polyamide- 66, polyamide - 1010 or polyamide- 11, were dissolved in m-cresol and the blend solution was cast in a glass and dried for preparing polyaniline composite films.Conductivity was from 10 -6 to 10 0Ω-1·cm-1 with different weight fraction of PAn-CSA. The crystallizttion of the films was studied by means of differential scanning calorimeter (DSC). The treatment of the composite films in different pH value solution would result in decrease of conductivity, especially in an alkaline solution.

  11. Structural, dielectric and magnetic properties of cobalt ferrite prepared using auto combustion and ceramic route

    Energy Technology Data Exchange (ETDEWEB)

    Murugesan, C., E-mail: murugesanscience@gmail.com; Perumal, M.; Chandrasekaran, G.

    2014-09-01

    Cobalt ferrite is synthesized by using low temperature auto combustion and high temperature ceramic methods. The prepared samples have values of lattice constant equal to 8.40 Å and 8.38 Å for auto combustion and ceramic methods respectively. The FTIR spectrum of samples of the auto combustion method shows a high frequency vibrational band at 580 cm{sup −1} assigned to tetrahedral site and a low frequency vibrational band at 409 cm{sup −1} assigned to octahedral site which are shifted to 590 cm{sup −1} and 412 cm{sup −1} for the ceramic method sample. SEM micrographs of samples show a substantial difference in surface morphology and size of the grains between the two methods. The frequency dependent dielectric constant and ac conductivity of the samples measured from 1 Hz to 2 MHz at room temperature are reported. The room temperature magnetic hysteresis parameters of the samples are measured using VSM. The measured values of saturation magnetization, coercivity and remanent magnetization are 42 emu/g, 1553 Oe, 18.5 emu/g for the auto combustion method, 66.7 emu/g, 379.6 Oe, and 17.3 emu/g for the ceramic method, respectively. The difference in preparation methods and size of the grains causes interesting changes in electrical and magnetic properties.

  12. Low dielectric loss in nano-Li-ferrite spinels prepared by sol–gel auto-combustion technique

    Indian Academy of Sciences (India)

    Mamata Maisnam; Nandeibam Nilima; Maisnam Victory; Sumitra Phanjoubam

    2016-02-01

    Pure and doped nano-Li-ferrite spinels were prepared by the sol–gel auto-combustion technique. The prepared ferrites were pelleted and heat treated at different temperatures. Structural characterization was carried out on the as-prepared samples and also on the heat-treated samples using X-ray diffraction (XRD). The studies confirmed the formation of single phase with spinel structures in all the samples. The crystallite size of the samples evaluated from XRD data was found to be 17–24 nm. Scanning electron microscopic photomicrographs revealed the microstructures and the grain size of these nanoferrites. The room-temperature dielectric constant and dielectric loss tangent, tan δ were measured as a function of frequency in the range 100 Hz–1 MHz. These nanoferrites showed the normal dielectric dispersion behaviour. The observed dielectric constant and dielectric loss tangent were found to be much lower than those measured on substituted Li-ferrites prepared by the conventional ceramic method. The results obtained were discussed in the paper.

  13. Magnetic properties of cobalt ferrite-silica nanocomposites prepared by a sol-gel autocombustion technique

    DEFF Research Database (Denmark)

    Cannas, C.; Musinu, A.; Piccaluga, G.

    2006-01-01

    The magnetic properties of cobalt ferrite-silica nanocomposites with different concentrations (15, 30, and 50 wt %) and sizes (7, 16, and 28 nm) of ferrite particles have been studied by static magnetization measurements and Mossbauer spectroscopy. The results indicate a superparamagnetic behavio...

  14. Layer-by-Layer Self-Assembled Ferrite Multilayer Nanofilms for Microwave Absorption

    Directory of Open Access Journals (Sweden)

    Jiwoong Heo

    2015-01-01

    Full Text Available We demonstrate a simple method for fabricating multilayer thin films containing ferrite (Co0.5Zn0.5Fe2O4 nanoparticles, using layer-by-layer (LbL self-assembly. These films have microwave absorbing properties for possible radar absorbing and stealth applications. To demonstrate incorporation of inorganic ferrite nanoparticles into an electrostatic-interaction-based LbL self-assembly, we fabricated two types of films: (1 a blended three-component LbL film consisting of a sequential poly(acrylic acid/oleic acid-ferrite blend layer and a poly(allylamine hydrochloride layer and (2 a tetralayer LbL film consisting of sequential poly(diallyldimethylammonium chloride, poly(sodium-4-sulfonate, bPEI-ferrite, and poly(sodium-4-sulfonate layers. We compared surface morphologies, thicknesses, and packing density of the two types of ferrite multilayer film. Ferrite nanoparticles (Co0.5Zn0.5Fe2O4 were prepared via a coprecipitation method from an aqueous precursor solution. The structure and composition of the ferrite nanoparticles were characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, transmission electron microscopy, and scanning electron microscopy. X-ray diffraction patterns of ferrite nanoparticles indicated a cubic spinel structure, and energy dispersive X-ray spectroscopy revealed their composition. Thickness growth and surface morphology were measured using a profilometer, atomic force microscope, and scanning electron microscope.

  15. Effects of Heating Processing on Microstructure and Magnetic Properties of Mn-Zn Ferrites Prepared via Chemical Co-precipitation

    Institute of Scientific and Technical Information of China (English)

    CHEN Shijie; XIA Jingbing; DAI Jianqing

    2015-01-01

    The fine powders of Mn-Zn ferrites with uniform size were prepared via chemical co-precipitation method. X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM), frequency dependence of permeability and metallographical microscope were used to investigate the crystal structure, surface topography and magnetic properties of the powders and the sintering samples. The experimental results demonstrate that the precursor powders have formed a pure phase cubic spinel MnxZn1-xFe2O4 while in the reactor and show deifnite magnetism, which can solve the dififcult issue in washing process effectively. When calcined beneath 450℃, the powders have intact crystal form and the crystallite size is less than 20 nm. Comparison tests of sintering temperatures show that 1 300℃ is the ideal sintering temperature for Mn-Zn ferrites prepared by using the chemical co-precipitation.

  16. Synthesis and characterization of hexagonal ferrite Sr{sub 1.8}Sm{sub 0.2}Co{sub 2}Ni{sub 1.50}Fe{sub 10.50}O{sub 22}/PST thin films for high frequency application

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Irshad, E-mail: irshadalibzu@gmail.com [Department of Physics, Bahauddin Zakariya University, Multan P.O. 60800 (Pakistan); Islam, M.U. [Department of Physics, Bahauddin Zakariya University, Multan P.O. 60800 (Pakistan); Ashiq, Muhammad Naeem, E-mail: naeemashiqqau@yahoo.com [Institute of Chemical Science, Bahauddin Zakariya University, Multan 60800 (Pakistan); Asif Iqbal, M. [Department of Physics, Bahauddin Zakariya University, Multan P.O. 60800 (Pakistan); College of E & ME, National University of Science and Technology, Islamabad (Pakistan); Karamat, Nazia [Institute of Chemical Science, Bahauddin Zakariya University, Multan 60800 (Pakistan); Azhar Khan, M. [Department of Physics, Islamia University, Bahawalpur 63100 (Pakistan); Sadiq, Imran [Centre of Excellence in Solid State Physics, University of The Punjab, Lahore (Pakistan); Ijaz, Sana [Institute of Chemical Science, Bahauddin Zakariya University, Multan 60800 (Pakistan); Shakir, Imran [Sustainable Energy Technologies (SET) Center, College of Engineering, King Saud University (Saudi Arabia)

    2015-11-01

    Y-type hexagonal ferrite (Sr{sub 1.8}Sm{sub 0.2}Co{sub 2}Ni{sub 1.50} Fe{sub 10.50}O{sub 22}) was prepared by a normal microemulsion route. The ferrite/polymer composites thin films are formed at different ferrite ratios in pure polystyrene matrix. The X-ray diffraction analysis shows broad peak at low angles which is due to the PST and the peaks for Y-type ferrite are also observed in composite samples. The peaks become more intense and show less broadening with increasing concentration of ferrite which suggests that crystallinity is improved with the addition of ferrite. DC resistivity of the composites samples is lower than that of the pure PST and decreases by increasing ferrite filler into the polymer. This decrease of resistivity is mainly due to the addition of comparatively less resistive ferrite into the highly insulating polymer matrix of PST. The observed increase in the dielectric constant (permittivity) with increasing concentration ratio of ferrites is mainly due to the electron exchange between Fe{sup 2+}↔Fe{sup 3+}+e{sup −} which consequently results in enhancement of electric polarization as well as dielectric constant. The existence of resonances peaks in the dielectric loss tangent spectra is due to the fact when the external applied frequency becomes equal to the jumping frequency of electrons between Fe{sup 2+} and Fe{sup 3+}. The increasing behavior of the dielectric constant, dielectric loss and AC conductivity with increasing ferrite ratio in PST matrix proposes their versatile use in different technological applications especially for electromagnetic shielding. - Highlights: • Y-type hexaferrites were synthesized by the microemulsion route. • AC activation is lower than DC activation energy. • Ferrite/polymer composites thin films are formed. • The peaks become more intense with increasing concentration of ferrite. • Values of “n” confirm the hopping mechanism in all thin films.

  17. Evaluation of humidity sensing properties of TMBHPET thin film embedded with spinel cobalt ferrite nanoparticles

    Science.gov (United States)

    Zafar, Qayyum; Azmer, Mohamad Izzat; Al-Sehemi, Abdullah G.; Al-Assiri, Mohammad S.; Kalam, Abul; Sulaiman, Khaulah

    2016-07-01

    In this study, we report the enhanced sensing parameters of previously reported TMBHPET-based humidity sensor. Significant improved sensing performance has been demonstrated by coupling of TMBHPET moisture sensing thin film with cobalt ferrite nanoparticles (synthesized by eco-benign ultrasonic method). The mean size of CoFe2O4 nanoparticles has been estimated to be 6.5 nm. It is assumed that the thin film of organic-ceramic hybrid matrix (TMBHPET:CoFe2O4) is a potential candidate for humidity sensing utility by virtue of its high specific surface area and porous surface morphology (as evident from TEM, FESEM, and AFM images). The hybrid suspension has been drop-cast onto the glass substrate with preliminary deposited coplanar aluminum electrodes separated by 40 µm distance. The influence of humidity on the capacitance of the hybrid humidity sensor (Al/TMBHPET:CoFe2O4/Al) has been investigated at three different frequencies of the AC applied voltage ( V rms 1 V): 100 Hz, 1 kHz, and 10 kHz. It has been observed that at 100 Hz, under a humidity of 99 % RH, the capacitance of the sensor increased by 2.61 times, with respect to 30 % RH condition. The proposed sensor exhibits significantly improved sensitivity 560 fF/ % RH at 100 Hz, which is nearly 7.5 times as high as that of pristine TMBHPET-based humidity sensor. Further, the capacitive sensor exhibits improved dynamic range (30-99 % RH), small hysteresis ( 2.3 %), and relatively quicker response and recovery times ( 12 s, 14 s, respectively). It is assumed that the humidity response of the sensor is associated with the diffusion kinetics of water vapors and doping of the semiconductor nanocomposite by water molecules.

  18. Preparation of composite electroheat carbon film

    Institute of Scientific and Technical Information of China (English)

    XIA Jin-tong; TU Chuan-jun; LI Yan; HU Li-min; DENG Jiu-hua

    2005-01-01

    A kind of conductive and heating unit, which can reach a high surface electroheat temperature at a low voltage, was developed in view of the traditional electroheat coating which has a low surface electroheat temperature and an insufficient heat resistance of its binder. The coating molded electroheat carbon film(CMECF) was prepared by carbonizing the coating which was prepared by adding modified resin into flake graphite and carbon fiber, coating molded onto the surface of the heat resisting matrix after dried, while the hot pressing molded electroheat thick carbon film(HPMETCF) was prepared by carbonizing the bodies whose powders were hot pressing molded directly.The surface and inner microstructure of the carbon film was characterized and analyzed by SEM and DSC/TG, while electroheat property was tested by voltage-current volume resistivity tester and electrical parameter tester. The results show that, close-packed carbon network configuration is formed within the composite electroheat carbon film film after anti-oxidizable treatment reaches a higher surface electroheat temperature than that of the existing electroheat coatings at a low voltage, and has excellent electroheat property, high thermal efficiency as well as stable physicochemical property. It is found that, at room temperature(19± 2 ℃) and 22 V for 5 min, the surface electroheat temperature of the self-produced CMECF (mfiller/mresin = 1. 8/1) reaches 112 ℃ while HPMETCF (mfiller/mresin = 3. 6/1) reaches 265 ℃.

  19. Faraday effect of bismuth iron garnet thin film prepared by mist CVD method

    Science.gov (United States)

    Yao, Situ; Sato, Takafumi; Kaneko, Kentaro; Murai, Shunsuke; Fujita, Koji; Tanaka, Katsuhisa

    2015-06-01

    Metastable bismuth iron garnet (BIG, an abbreviation of Bi3Fe5O12), one kind of garnet-type ferrites, is known to manifest very large Faraday rotation as well as low optical absorption in the visible to infrared region. We report on successful synthesis of thin film composed of single-phase BIG epitaxially grown on single-crystalline gadolinium gallium garnet (Gd3Ga5O12, GGG) substrate by using mist chemical vapor deposition (CVD) method, which is an emerging technique for preparation of thin films. The crystal structure, surface morphology, and magnetic, optical and magneto-optical properties of the resultant thin films have been explored. The BIG thin film has a relatively flat surface free from roughness compared to those prepared by other vapor deposition methods. Saturation magnetization is about 1620 G at room temperature, which is close to that expected from the ideal magnetic structure of BIG. The maximum value of Faraday rotation angle reaches 54.3 deg/µm at a wavelength of 424 nm. This value is rather large when compared with those reported for BIG thin films prepared by other techniques. The wavelength dependence of Faraday rotation angle is analyzed well in terms of the crystal electric field (CEF) level schema. Our result suggests that the mist CVD method is a simple and effective technique to synthesize BIG thin film with excellent magneto-optical properties.

  20. Preparation of silica coated cobalt ferrite magnetic nanoparticles for the purification of histidine-tagged proteins

    Science.gov (United States)

    Aygar, Gülfem; Kaya, Murat; Özkan, Necati; Kocabıyık, Semra; Volkan, Mürvet

    2015-12-01

    Surface modified cobalt ferrite (CoFe2O4) nanoparticles containing Ni-NTA affinity group were synthesized and used for the separation of histidine tag proteins from the complex matrices through the use of imidazole side chains of histidine molecules. Firstly, CoFe2O4 nanoparticles with a narrow size distribution were prepared in an aqueous solution using the controlled co-precipitation method. In order to obtain small CoFe2O4 agglomerates, oleic acid and sodium chloride were used as dispersants. The CoFe2O4 particles were coated with silica and subsequently the surface of these silica coated particles (SiO2-CoFe2O4) was modified by amine (NH2) groups in order to add further functional groups on the silica shell. Then, carboxyl (-COOH) functional groups were added to the SiO2-CoFe2O4 magnetic nanoparticles through the NH2 groups. After that Nα,Nα-Bis(carboxymethyl)-L-lysine hydrate (NTA) was attached to carboxyl ends of the structure. Finally, the surface modified nanoparticles were labeled with nickel (Ni) (II) ions. Furthermore, the modified SiO2-CoFe2O4 magnetic nanoparticles were utilized as a new system that allows purification of the N-terminal His-tagged recombinant small heat shock protein, Tpv-sHSP 14.3.

  1. Characterization of Ni ferrites powders prepared by plasma arc discharge process

    Science.gov (United States)

    Safari, A.; Gheisari, Kh.; Farbod, M.

    2017-01-01

    The aim of this work was to synthesize a single-phase spinel structure from a mixture of zinc, iron and nickel powders by plasma arc discharge method. A mixture of zinc, iron and nickel powders with the appropriate molar ratio was prepared and formed into a cylindrical shape. The synthesis process was performed in air, oxygen and argon atmospheres with the applied arc current of 400 A and pressure of 1 atm. After establishing an arc between the electrodes, the produced powders were collected and their structure and magnetic properties were examined by XRD and VSM, respectively. ZnO as an impurity was appeared in the as-produced powders owing to the high reactivity of zinc atoms, preventing the formation of Ni-Zn ferrite. A pure spinel structure with the highest saturation magnetization (43.8 emu/g) was observed as zinc powders removed completely from the initial mixture. Morphological evaluations using field emission scanning electron microscopy showed that the mean size of fabricated nanoparticles was in the range 100-200 nm and was dependent on the production conditions.

  2. Preparation and microwave absorbing properties of graphene oxides/ferrite composites

    Science.gov (United States)

    Liang, Kun; Qiao, Xiao-Jing; Sun, Zhi-Gang; Guo, Xiao-Dang; Wei, Long; Qu, Yang

    2017-06-01

    The graphene oxides (GO) and the graphene-based composites have been synthesized successfully by Hummer method and Hydrothermal-calcination process, respectively. The effects of solvent (water, ethylene glycol, glycerol and glycol-glycerol), the consumption of graphite oxides (GO = 0.1, 0.5, 1.0, 2.0 wt%) on the crystallization, morphology and performance of the target samples have been investigated. The obtained samples have been characterized by FTIR, XRD, SEM and HRTEM. The precursors obtained through hydrothermal process are composed of 80 nm ferromagnetic polyhedral particles and the uniformly distributed covering GO layers. After calcination, the 200 nm ferromagnetic nanoparticles can be achieved on the surface of graphene films. The results indicate that the optimized samples can be obtained at GO = 0.1 wt% under water system. Also, the electromagnetic properties and microwave absorbing performance have been measured by VNA. The addition of GO is conducive to improve the absorbing property of ferrites by shifting the reflectivity peak into lower frequency range and sharping the maximum value. At GO = 0.1%, the maximum RL peaks can reach -17.15 dB at 3.3 GHz, with the bandwidth below -10 dB ranging from 2.8 to 3.8 GHz under 3 mm thickness. For GO = 1.0 wt%, twin peaks appear at 4.3 and 15.6 GHz of 3.5 mm thickness, and the bandwidth below -10 dB reaches 2.6 GHz (10.3-12.9 GHz) at 1.5 mm thickness.

  3. Moessbauer and magnetic studies of cobalt substituted lithium zinc ferrites prepared by citrate precursor method

    Energy Technology Data Exchange (ETDEWEB)

    Soibam, Ibetombi [Department of Physics, Manipur University, Canchipur, Imphal 795003, Manipur (India)], E-mail: ibetombi_phys@rediffmail.com; Phanjoubam, Sumitra [Department of Physics, Manipur University, Canchipur, Imphal 795003, Manipur (India); Prakash, Chandra [Directorate of ER and IPR, DRDO Bhawan, Rajaji Marg, New Delhi 110011 (India)

    2009-05-05

    Nanocrystalline lithium zinc ferrites substituted with cobalt were synthesized by the citrate precursor method. X-ray diffraction was used to confirm the spinel phase. Moessbauer studies at room temperature were carried out to study the effect of cobalt concentration on the various hyperfine interactions. Variation of the saturation magnetization with respect to composition was discussed. The result shows some anomalous behaviour when cobalt is substituted to lithium ferrite in presence of zinc.

  4. Synthesis and characterization of nano-sized cobalt ferrite prepared via polyol method using conventional and microwave heating techniques

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, Amal M., E-mail: amozarei@yahoo.co [Surface Chemistry and Catalysis Laboratory, Physical Chemistry Department, National Research Center, Al Buhouth St., Cairo (Egypt); El-Latif, M.M. Abd; Mahmoud, Morsi M. [Fabrication Technology Department, Advanced Technology and New Materials Research Institute, Mubarak City for Scientific Research and Technology Applications, Alexandria (Egypt)

    2010-09-10

    Nano-sized single-phase cobalt ferrite samples were prepared via polyol method using ethylene glycol as a high boiling point solvent as well as a reducing agent. These samples were prepared by two different heating techniques; conventional heating technique and microwave assisting technique using a 2.45 GHz multimode microwave synthesis unit. The crystallite size of the obtained samples was found to be in the range from 10 nm to 12 nm. The obtained samples were characterized using transmission electron microscope (TEM) and X-ray diffraction (XRD). Quantum design SQUID magnetometer was used to study the magnetic measurement.

  5. Study of 200 MeV Ag{sup 15+} ion induced amorphisation in nickel ferrite thin films

    Energy Technology Data Exchange (ETDEWEB)

    Dixit, Gagan, E-mail: gagandikshit@yahoo.i [Department of Physics, Govind Ballabh University of Ag. and Technology, Pantnagar, Uttarakhand 263 145 (India); Singh, Jitendra Pal, E-mail: Jitendra_singh2029@rediffmail.co [Department of Physics, Govind Ballabh University of Ag. and Technology, Pantnagar, Uttarakhand 263 145 (India); Srivastava, R.C., E-mail: rcsri@rediffmail.co [Department of Physics, Govind Ballabh University of Ag. and Technology, Pantnagar, Uttarakhand 263 145 (India); Agrawal, H.M., E-mail: hma001@rediffmail.co [Department of Physics, Govind Ballabh University of Ag. and Technology, Pantnagar, Uttarakhand 263 145 (India)

    2011-01-15

    Thin films of nickel ferrite of thickness {approx}100 and 150 nm were deposited by pulsed laser deposition. The films were irradiated with a 200 MeV Ag{sup 15+} beam of three fluences 1 x 10{sup 12}, 2 x 10{sup 12} and 4 x 10{sup 12} ions/cm{sup 2}. X-ray diffraction showed a decrease in the intensity of peaks indicating progressive amorphisation with increased irradiation fluence. Fourier transform infra-red and Raman spectra of pristine and irradiated films were also recorded which showed a degradation of the crystallinity of the samples after irradiation. The damage cross section of the infra-red bands was determined. It was found that the two bands at 557 and 614 cm{sup -1} did not show similar behaviour with fluence.

  6. Structural and magnetic properties of zinc ferrite thin films irradiated by 90 keV neon ions

    Science.gov (United States)

    Gafton, E. V.; Bulai, G.; Caltun, O. F.; Cervera, S.; Macé, S.; Trassinelli, M.; Steydli, S.; Vernhet, D.

    2016-08-01

    The effects of 90 keV neon beam irradiation on the structure and magnetic properties of zinc ferrite thin films have been investigated through several methods, namely, X-ray diffraction technique, Vibrating Sample and SQUID magnetometers. Beforehand, the pristine have also been characterized using profilometry and microscopy techniques. In particular single-phase formation of the thin films deposited on monocrystalline Si (111) substrate by pulsed laser deposition technique was confirmed. Crystal lattice, coercivity, saturation magnetization have been studied for the first time, as a function of ion penetration depth and irradiation fluence. The chemical composition and the crystallinity of the films are not affected with the ion impact acting as a mechanical stress relief. On the contrary, both magnetization and coercivity are sensitive to Neq+ ion irradiation and exhibit different behaviours depending on the ion fluence range.

  7. Structure and magnetic properties of Co and Ni nano-ferrites prepared by a two step direct microemulsions synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Pulišová, P., E-mail: pulisovap@yahoo.com [Faculty of Metallurgy, Technical University of Košice, Park Komenského 3, 04200 Košice (Slovakia); Institute of Inorganic Chemistry of the AS CR, v.v.i., Husinec-Řež 1001, 25068 Řež (Czech Republic); Kováč, J. [Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 04001 Košice (Slovakia); Voigt, A. [Process Systems Engineering, Otto-von-Guericke Universität Magdeburg, Universitätsplatz 2, 39106 Magdeburg (Germany); Raschman, P. [Faculty of Metallurgy, Technical University of Košice, Park Komenského 3, 04200 Košice (Slovakia)

    2013-09-15

    Nano-particles of CoFe{sub 2}O{sub 4}, NiFe{sub 2}O{sub 4} and Co{sub 0.5}Ni{sub 0.5}Fe{sub 2}O{sub 4} were synthesized by a two step microemulsion precipitation where inverse micelles of water in hexanol were stabilized using cetyltrimethylammonium bromide. Powder X-ray diffraction analysis and Transmission electron microscopy measurements provided data to clarify the crystal structure and size of the produced nano-particles. Different measurements of magnetic properties at low temperatures of 2 K revealed that nano-particles of NiFe{sub 2}O{sub 4} represent magnetically soft ferrite with a coercivity ∼40 kA/m, whereas nano-particles of CoFe{sub 2}O{sub 4} and Co{sub 0.5}Ni{sub 0.5}Fe{sub 2}O{sub 4} were magnetically harder with a coercivity of 815 and 947 kA/m, respectively. Additionally zero field cooling and field cooling measurements provided data for estimating the blocking temperature of the materials produced. For NiFe{sub 2}O{sub 4} this temperature is lower, 23 K. The blocking temperature of CoFe{sub 2}O{sub 4} of 238 K and Co{sub 0.5}Ni{sub 0.5}Fe{sub 2}O{sub 4} of 268 K are higher in comparison with NiFe{sub 2}O{sub 4}. - Highlights: • Nano-scale ferrites prepared by precipitation in microemulsions show magnetic behavior. • XRD and TEM found that particle size of prepared magnetic nano-ferrites is in range from 5 to 10 nm. • Prepared CoFe{sub 2}O{sub 4} and Co{sub 0.5}Ni{sub 0.5}Fe{sub 2}O{sub 4} ferrites are magnetically harder than NiFe{sub 2}O{sub 4} ferrite. • Precipitation in microemulsions offers preparation at low temperature as cost effective method.

  8. PREPARATION AND CHARACTERIZATION OF POLY-CRYSTALLINE SILICON THIN FILM

    Institute of Scientific and Technical Information of China (English)

    Y.F. Hu; H. Shen; Z.Y. Liu; L.S. Wen

    2003-01-01

    Poly-crystalline silicon thin film has big potential of reducing the cost of solar cells.In this paper the preparation of thin film is introduced, and then the morphology of poly-crystalline thin film is discussed. On the film we developed poly-crystalline silicon thin film solar cells with efficiency up to 6. 05% without anti-reflection coating.

  9. Enhancement in dielectric and magnetic properties of Ni–Zn ferrites prepared by sol–gel method

    Energy Technology Data Exchange (ETDEWEB)

    Nasir, S. [Applied Thermal Physics Laboratory, Department of Physics, COMSATS Institute of Information Technology, Islamabad 44000, Pakistan. (Pakistan); Department of Materials Science and Engineering, Zhejiang University (China); Saleemi, A.S.; Fatima-tuz-Zahra [Applied Thermal Physics Laboratory, Department of Physics, COMSATS Institute of Information Technology, Islamabad 44000, Pakistan. (Pakistan); Anis-ur-Rehman, M., E-mail: marehman@comsats.edu.pk [Applied Thermal Physics Laboratory, Department of Physics, COMSATS Institute of Information Technology, Islamabad 44000, Pakistan. (Pakistan)

    2013-09-25

    Highlights: •Cr-Zn co-doped Ni-Zn ferrites were prepared with a newly reported sol gel method. •Phase purity and a very good control of crystallite and particle size are obtained. •Low eddy current losses are obtained due to low dielectric losses. •Operational frequency of doped Ni-Zn ferrites could be increased up to GHz ranges. -- Abstract: Due to its high permeability, Mn–Zn ferrite is the material of choice for high frequency applications up to a few MHz. At increased operational frequency, Ni–Zn ferrites are more suitable than Mn–Zn ferrites due to their low eddy current losses and low dielectric losses. To combine all these properties and to increase the operational frequency up to GHz, we have prepared Ni{sub 0.5}Zn{sub 0.5}Cr{sub x}Mn{sub 0.5−x}Fe{sub 1.5}O{sub 4} (x = 0.1, 0.2, 0.3, 0.4, 0.5), with a simplified sol gel method. Prepared samples show high saturation magnetization, low coercivity, and low dielectric loss. The dielectric loss in the frequency range 1 MHz to 1.3 GHz remained almost constant as the Cr content was increased in the samples. The crystallite size and lattice parameters of these samples were calculated from X-ray Diffraction (XRD) data analysis. The crystallite size for each sample was calculated using the Scherrer formula considering the most intense peak (3 1 1) and the results were compared with the Scanning Electron Microscope (SEM) images of these samples. Powder X-ray diffraction (XRD) patterns confirmed the single phase spinel structure for these samples. Wayne Kerr Precession Component Analyzer 6440B and Agilent E4991 Impedance Analyzer were used to study the dielectric constant (ε′) and the dielectric loss tangent (tan δ) of these samples as a function of frequency in the frequency range 100 Hz to 1 MHz and 1 MHz to 1.29 GHz respectively. Quantum design PPMS model 6700 was used to study the magnetic properties of these samples.

  10. Preparation and Magnetic Properties of Mn-Zn Ferrites by the Co-precipitation Method

    Institute of Scientific and Technical Information of China (English)

    LI Xue; REN Ping; ZHANG Junxi; ZHANG Lingsong; LIU Guoping

    2009-01-01

    Mn-Zn ferrites(Mn_(1-x)Zn_xFe_2O_4)with different compositions were prepared by the coprecipitation method,and the influences of such synthesis conditions as pH value,composition and volume ratio(R)of the mixed solution and NH_4HCO_3 solution on their microstructures and magnetic properties were discussed.The samples were characterized by X-ray diffraction(XRD)and magneti-zation measurement instrument.Lattice parameters and average crystalline size of the synthesized materials were calculated from the corresponding XRD patterns with the related software Jade.5.For samples of different pH values,only one phase was found when pH values were 7.0,8.0 and 9.0.The sample with pH value of 7.0 exhibited the highest saturation magnetic induction,the lowest coercive force,and crystallized best.For samples of different R values with pH value of 7.0,only one phase was observed in all samples,and the sample with R value of 2.3 exhibited the highest saturation magnetic induction and the lowest coercive force.The composition has mainly afected the magnetic properties,and the saturation magnetic induction increases with the increase of the content of Zn(x),but decreases when x is beyond 0.6.The trend of coercive force is on the contrary.However,no magnetism is ex-hibited when the x value is up to 0.8.

  11. Magnetic properties of nanosized Gd doped Ni–Mn–Cr ferrites prepared using the sol–gel autocombustion technique

    Energy Technology Data Exchange (ETDEWEB)

    Samoila, P., E-mail: samoila.petrisor@icmpp.ro [“Petru Poni” Institute of Macromolecular Chemistry, Iasi 700487 (Romania); Sacarescu, L. [“Petru Poni” Institute of Macromolecular Chemistry, Iasi 700487 (Romania); Borhan, A.I. [Faculty of Chemistry, Al.I. Cuza University, Iasi 700506 (Romania); Timpu, D. [“Petru Poni” Institute of Macromolecular Chemistry, Iasi 700487 (Romania); Grigoras, M.; Lupu, N. [National Institute of R and D for Technical Physics, Iasi 700050 (Romania); Zaltariov, M.; Harabagiu, V. [“Petru Poni” Institute of Macromolecular Chemistry, Iasi 700487 (Romania)

    2015-03-15

    Ni{sub 0.8}Mn{sub 0.2}Cr{sub 0.5}Fe{sub 1.5-x}Gd{sub x}O{sub 4} (where x=0, 0.02, 0.04, 0.06, 0.08) spinel ferrites were synthesized by a sol–gel autocombustion technique using citric acid as fuel. Effect of Gd doping on structural and magnetic properties of Ni–Mn–Cr ferrites is reported. The phase composition of the prepared samples was analyzed by X-ray diffraction and Fourier transform infrared spectroscopy, and the magnetic measurements were realized using a vibrating sample magnetometer. XRD and FT-IR analysis reveal pure spinel phase in all the samples, without traces of secondary phases. The grain sizes were estimated from the TEM micrographs and were found to decrease with the doping ions concentration from 43 to 10 nm. It was revealed from the hysteresis loop of the materials that magnetization and coercivity followed decreasing trend with substitution of Fe{sup 3+} magnetic ions by Gd{sup 3+} ions. Also, introducing Gd ions into the spinel lattice led to the decrease in Curie temperature. - Highlights: • Gd doped Ni–Mn–Cr ferrites were obtained using the sol–gel autocombustion technique. • XRD and IR analysis reveals the pure spinel structure. • Average grain size decrease with Gd-content. • Saturation magnetization, coercivity and Curie temperature decrease with Gd doping.

  12. Physicochemical Properties of Nanocrystallite Copper Ferrite Prepared by a Novel Self Flash Combustion of Acetate Precursors

    Institute of Scientific and Technical Information of China (English)

    M.H. Khedr; A.A.Farghali

    2005-01-01

    Copper ferrite, CuFe2O4, one of the important ferrites due to its interesting electrical, magnetic and structural properties, is obtained by a novel self flash combustion of a homogeneous mixture of one mole copper acetate (89 nm) copper ferrite (less than 100%) is obtained at lower temperatures, whereas 100% copper ferrite is obtained after calcination at 1000℃. Thermal analysis (TG and DTA), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), photo microscopy, magnetic and porosity measurements have been carried out for the specimens obtained after calcinations at 700, 800, 900 and 1000℃ to characterize the conversion efficiency of the powder precursors to copper ferrite. It was found that increasing temperature leads to great improvement in the magnetic properties. By increasing calcination temperature from 700~1000℃ saturation magnetic flux density (Bs) increased from 17.8 to 40.8 emu/g, while remnant magnetic flux density (Br) increased from 10.1 to 17.11 emu/g.

  13. Preparation and Sinterability of Mn-Zn Ferrite Powders by Sol-Gel Method

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Mn-Zn spinel ferrites were synthesized by sol-gel method. Effects of calcined temperature on structure and particle size of MnZnFe2O4 were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD patterns indicate that the ultra fine Mn-Zn ferrite exhibits a spinel crystal structure. SEM images show that the powder fired at 900 ℃ for 2 h has an average diameter of 60~90 nm. The particle size becomes larger with the increasing of calcined temperature and the distribution of particle becomes even more homogeneous. Sintering behaviors of synthesized ferrite powders depend on the powder characteristics and high temperatures have induced the good crystallization of particles.

  14. Characterization of cadmium substituted nickel ferrites prepared using auto-combustion technique

    Directory of Open Access Journals (Sweden)

    Manojit De

    2015-12-01

    Full Text Available In the present paper we have investigated synthesis of nickel ferrite (NiFe2O4 and cadmium substituted nickel ferrite (Ni1-xCdxFe2O4 powders with particles’ size in nanometer range using auto combustion technique as well as their sinterability. XRD analysis of the sintered samples confirmed the formation of single phase materials and the lattice parameter was increased with increase in cadmium concentration. It has also been observed that the estimated bulk densities of the materials decrease with increase in cadmium concentration, while they increase with the rise of sintering temperature.

  15. Thick film traps with an irregular film. Preparation and evaluation.

    Science.gov (United States)

    Kloskowski, Adam; Pettersson, Johan; Roeraade, Johan

    2004-05-07

    A new method for preparation of sorbent-based ultra-thick film traps for concentration of trace volatile components from gaseous matrices is described. The procedure is based on blowing a prepolymer (polydimethylsiloxane) through a capillary tube, forming an irregular film of stationary phase. Subsequently, the prepolymer is immobilized in a few seconds by heating to 200 degrees C. Evaluation of the performance of the new traps showed that the loss of efficiency, compared to regular smooth film traps is only on the order of 20-30%. In terms of breakthrough volume, this loss in performance is rather insignificant. The technology is extremely simple and allows a rapid and cheap production of a large number of ultra-thick film traps, even in non-specialized laboratories. The method can be applied to any type of cross-linkable stationary phase, thereby expanding the scope of sorbent-based trapping and preconcentration concept. Many applications are anticipated in trace and ultra-trace analysis in a wide range of fields, such as environmental chemistry, polymers, food and process analysis.

  16. Effect of pH value on electromagnetic loss properties of Co-Zn ferrite prepared via coprecipitation method

    Science.gov (United States)

    Huang, Xiaogu; Zhang, Jing; Wang, Wei; Sang, Tianyi; Song, Bo; Zhu, Hongli; Rao, Weifeng; Wong, Chingping

    2016-05-01

    In this paper, the cobalt zinc ferrite was prepared by coprecipitation method at different pH conditions. The influence of pH values on the coprecipitation reaction was theoretically analyzed at first. The calculated results showed that the pH values should be controlled in the range of 9-11 to form the stable precipitation. The XRD investigation was used to further confirm the formation of the composite on specific pH values. In addition, the morphological study revealed that the average particle size of the composite decreased from 40 nm to 30 nm when the pH value increased from 9-11. The variation of microstructure plays a critical role in controlling the electromagnetic properties. From the electromagnetic analysis, the dielectric loss factor was 0.02-0.07 and magnetic loss factor was 0.2-0.5 for the composite synthesized at pH of 9, which presents dramatically improved dielectric loss and magnetic loss properties than the samples prepared at pH of 10 and 11. The as-prepared cobalt zinc ferrite are highly promising to be used as microwave absorption materials.

  17. Er3+-substituted W-type barium ferrite: preparation and electromagnetic properties

    Institute of Scientific and Technical Information of China (English)

    HUANG

    2010-01-01

    Er3+-substituted W-type barium ferrites Ba1-xErx(Zn0.3Co0.7)2Fe16O27(x=0.00,0.05,0.10,0.15,0.20)were synthesized by polymer adsorbent combustion method.Samples were characterized by X-ray diffraction analysis(XRD),X-ray fluorescence(XRF),scanning electron microscopy(SEM)and network analyzer to investigate the relationships among Er3+concentration,crystal structure,surface mcrphology and electromagnetic properties.All the XRD patterns showed pure phase of W-type barium ferrite when x≤0.15,while the impurity phase of ErFeO3 appeared when x=0.20.The pure W-type barium ferrite showed a hexagonal flake shape.In addition,the microwave electromagnetic properties of samples were analyzed in the frequency range of 2-18 GHz.It was indicated that the electromagnetic properties were significantly improved when Er3+doping content was 0.10.The reasons were also discussed using electromagnetic theory.The optimized ferrite exhibited excellent microwave absoption performance.The maximum of reflection loss(RL)reached about-27.4 dB and RL was below-10dB at the frequency range from 8.4 GHz to 18 GHz,when the thickness was 2.6 mm.

  18. Magnetic properties of cobalt ferrite-silica nanocomposites prepared by a sol-gel autocombustion technique.

    Science.gov (United States)

    Cannas, C; Musinu, A; Piccaluga, G; Fiorani, D; Peddis, D; Rasmussen, H K; Mørup, S

    2006-10-28

    The magnetic properties of cobalt ferrite-silica nanocomposites with different concentrations (15, 30, and 50 wt %) and sizes (7, 16, and 28 nm) of ferrite particles have been studied by static magnetization measurements and Mossbauer spectroscopy. The results indicate a superparamagnetic behavior of the nanoparticles, with weak interactions slightly increasing with the cobalt ferrite content and with the particle size. From high-field Mossbauer spectra at low temperatures, the cationic distribution and the degree of spin canting have been estimated and both parameters are only slightly dependent on the particle size. The magnetic anisotropy constant increases with decreasing particle size, but in contrast to many other systems, the cobalt ferrite nanoparticles are found to have an anisotropy constant that is smaller than the bulk value. This can be explained by the distribution of the cations. The weak dependence of spin canting degree on particle size indicates that the spin canting is not simply a surface phenomenon but also occurs in the interiors of the particles.

  19. Higher d.c. resistivity of Li–Zn–Cd ferrites prepared by microwave sintering compared with conventional sintering

    Indian Academy of Sciences (India)

    Mamata Maisnam; Sumitra Phanjoubam

    2014-10-01

    Cd2+-substituted Li–Zn ferrites having the general formula Li$^{+}_{0.4–x/2}$Zn$^{2+}_{0.2}$Cd$^{2+}_{x}$Fe$^{3+}_{2.4–x/2}$O$^{2-}_{4}$ where x = 0.02, 0.03 and 0.04 have been prepared by both microwave sintering and conventional sintering. In the former case, sintering was done at 1050 °C for 25 min, whereas in the latter case sintering was done at 1050 °C for 6 h. The various structural properties, microstructures and d.c. resistivity of the samples prepared by the two techniques were compared. The study showed higher d.c. resistivity and higher activation energies in the samples prepared by microwave sintering. The mechanisms pertaining to the results are discussed.

  20. Effect of zinc substitution on Co-Zn and Mn-Zn ferrite nanoparticles prepared by co-precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Arulmurugan, R. [Department of Physics, Pondicherry Engineering College, Pondicherry 605014 (India)]. E-mail: arulphysics@rediffmail.com; Jeyadevan, B. [Graduate School of Environmental Studies, Tohoku University, Sendai 980-8579 (Japan); Vaidyanathan, G. [Department of Physics, Pondicherry Engineering College, Pondicherry 605014 (India)]. E-mail: gvn_pec@yahoo.com; Sendhilnathan, S. [Department of Physics, Sri Manakula Vinayagar Engineering College, Pondicherry 605 107 (India)

    2005-03-01

    Co{sub (1-x)}Zn{sub x}Fe{sub 2}O{sub 4} and Mn{sub (1-x)}Zn{sub x}Fe{sub 2}O{sub 4} (x=0.1-0.5) nanoparticles less than 12nm are prepared by chemical co-precipitation method which could be used for ferrofluid preparation. X-ray diffraction (XRD), Transmission electron microscopy (TEM), Vibrational sample magnetometer (VSM) and Thermo gravimetric analysis (TGA) are utilized in order to study the effect of variation in the Zn substitution and its impact on particle size, magnetic properties like M{sub S}, H{sub C}, Curie temperature, thermomagnetic coefficient and associated water content. Atomic absorption spectroscopy was used for the estimation of cobalt, zinc and manganese and Fe{sup 3+} ion was estimated using spectrophotometer. The saturation magnetization of the Co-Zn substituted ferrite nanoparticles decreases continuously with the increase in Zn concentration, whereas for the Mn-Zn substituted ferrite nanoparticle the saturation magnetization was maximum for x=0.2 and decreases on further increase in Zn concentration. The particle size decreases with the increase in the Zn concentration for both Co-Zn and Mn-Zn ferrites. The estimation of associated water content, which increases with the Zn concentration, plays a vital role for the correct determination of cation contents. The Curie temperature and the temperature at which maximum value of thermomagnetic coefficient observed simultaneously decrease with the increase in the initial substitution degree of zinc.

  1. Preparation and characterization of CoFe2O4/TiO2 magnetic composite films

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    CoFe2O4/TiO2 magnetic composite films were prepared using the sol-gel method with tetrabutyltitanate and metallic chlorates as starting materials. The effects of heat treatment temperatures on micro- structures and on magnetic properties were studied. The microstructure and properties of the samples at different heat treatment temperatures were characterized by X-ray diffraction, Raman spectrum, scanning electron microscopy, polarized microscopy and vibrating sample magnetometry. The results show that crystals of different substances grow up independently. Cobalt ferrite is evenly embedded into the titanium dioxide matrix in the prepared composite films. The magnetism of the composite films is enhanced with an increase of the heat temperature.

  2. Preparation of hollow microspheres of Ce3+ doped NiCo ferrite with high microwave absorbing performance

    Science.gov (United States)

    Duan, Hong-zhen; Zhou, Fang-ling; Cheng, Xia; Chen, Guo-hong; Li, Qiao-ling

    2017-02-01

    Hollow microspheres of Ce3+ doped NiCo-ferrites were synthesized by template-based-deposition and surface reaction method with carbon sphere as the template. The phase structure, morphology, magnetic properties and wave absorbing properties of the sample were characterized by X-ray powder diffraction(XRD), Scanning electronic microscopy(SEM), Vibration sample magnetometer (VSM) and a network vector analyzer (NVA), respectively. The results indicated that the particle size of the carbon sphere sample prepared by hydrothermal method was about 0.5 μm and the particle size of the Ni0.5Co0.5Fe2O4 sample prepared by template-based method was about 300 nm. The influence of the amount of rare earth element on the magnetic and absorbing properties of sample was studied. The saturation magnetization and coercivity decreased gradually with the increase of the content of Ce. When the content of Ce was 0.02, the maximal saturation magnetization value and coercivity was 75.72 emu•g-1 and 789.88 Oe, respectively. The associated ferrite hollow spheres have good absorbing performance, and the return loss value was -18.8 dB at 5500 MHz.

  3. Preparation of Mn-Zn ferrite nanoparticles and their silica-coated clusters: Magnetic properties and transverse relaxivity

    Science.gov (United States)

    Kaman, Ondřej; Kuličková, Jarmila; Herynek, Vít; Koktan, Jakub; Maryško, Miroslav; Dědourková, Tereza; Knížek, Karel; Jirák, Zdeněk

    2017-04-01

    Hydrothermal synthesis of Mn1-xZnxFe2O4 nanoparticles followed by direct encapsulation of the as-grown material into silica is demonstrated as a fast and facile method for preparation of efficient negative contrast agents based on clusters of ferrite crystallites. At first, the hydrothermal procedure is optimized to achieve strictly single-phase magnetic nanoparticles of Mn-Zn ferrites in the compositional range of x≈0.2-0.6 and with the mean size of crystallites ≈10 nm. The products are characterized by powder X-ray diffraction, X-ray fluorescence spectroscopy, and SQUID magnetometry, and the composition close to x=0.4 is selected for the preparation of silica-coated clusters with the mean diameter of magnetic cores ≈25 nm. Their composite structure is studied by means of transmission electron microscopy combined with detailed image analysis and magnetic measurements in DC fields. The relaxometric studies, performed in the magnetic field of B0=0.5 T, reveal high transverse relaxivity (r2(20 °C)=450 s-1 mmol(Me3O4)-1 L) with a pronounced temperature dependence, which correlates with the observed temperature dependence of magnetization and is ascribed to a mechanism of transverse relaxation similar to the motional averaging regime.

  4. Preparation and Thermal Characterization of Diamond-Like Carbon Films

    Institute of Scientific and Technical Information of China (English)

    BAI Su-Yuan; TANG Zhen-An; HUANG Zheng-Xing; Yu Jun; WANG Jing; LIU Gui-Chang

    2009-01-01

    Diamond-like carbon (DLC) films are prepared on silicon substrates by microwave electron cyclotron resonance plasma enhanced chemical vapor deposition. Raman spectroscopy indicates that the films have an amorphous structure and typical characteristics. The topographies of the films are presented by AFM images. Effective thermal conductivities of the films are measured using a nanosecond pulsed photothermal reflectance method. The results show that thermal conductivity is dominated by the microstructure of the films.

  5. A review on preparation techniques for synthesis of nanocrystalline soft magnetic ferrites and investigation on the effects of microstructure features on magnetic properties

    Science.gov (United States)

    Hajalilou, Abdollah; Mazlan, Saiful Amri

    2016-07-01

    Soft magnetic materials have been used in many applications, i.e., electrical and electronic industries, due to their desirable electromagnetic characteristics. The performance of these materials in bulk form, where the size of grains is in micrometer scale, is only limited to a few megahertz frequencies due to their higher conductivity and domain wall resonance. Synthesizing the ferrite particles in nanometer scales before compacting them for sintering would be one way to solve using these materials at higher frequencies. The properties of ferrite depend mainly on the technique and conditions of preparation, which, in turn, affect the cation distribution over the tetrahedral and octahedral sites. Thus, the aim of this study was to introduce some methods used for synthesizing nanocrystalline soft magnetic ferrites. Furthermore, the microstructure features, i.e., grain sizes and porosities, which are influenced by the types of method used for preparation, playing key role on the magnetic properties of the sample, are also highlighted.

  6. Preparation, Characterization and Magnetic Properties of PANI/La-substituted LiNi Ferrite Nanocomposites

    Institute of Scientific and Technical Information of China (English)

    JIANG, Jing; LI, Liang-Chao; XU, Feng

    2006-01-01

    Magnetic nanocomposites containing polyaniline (PANI)-coated La-substituted LiNi ferrite (LiNi0.5La0.02Fe1.98O4)were synthesized by in situ polymerization in aqueous solution of hydrochloric acid. The nanocomposites exhibited the magnetic hysteresis nature under applied magnetic field. The saturation magnetization (Ms) and coercivity (Hc)varied with the ferrite content. The obtained nanocomposites were characterized by X-ray diffraction (XRD),transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), UV-Visible spectroscopy and vibrating sample magnetometer (VSM). TEM and SEM studies showed that the nanocomposites present the core-shell structure. The results of XRD patterns, FT-IR and UV-Visible spectra indicated the formation of PANI-LiNi0.5La0.02Fe1.98O4 nanocomposites and showed that the interaction existed between PANI backbone and ferrite particles in the nanocomposites. The bonding mechanism in the nanocomposites has been proposed.

  7. Preparation of Magnesium, Cobalt and Nickel Ferrite Nanoparticles from Metal Oxides using Deep Eutectic Solvents.

    Science.gov (United States)

    Söldner, Anika; Zach, Julia; Iwanow, Melanie; Gärtner, Tobias; Schlosser, Marc; Pfitzner, Arno; König, Burkhard

    2016-09-05

    Natural deep eutectic solvents (DESs) dissolve simple metal oxides and are used as a reaction medium to synthesize spinel-type ferrite nanoparticles MFe2 O4 (M=Mg, Zn, Co, Ni). The best results for phase-pure spinel ferrites are obtained with the DES consisting of choline chloride (ChCl) and maleic acid. By employing DESs, the reactions proceed at much lower temperatures than usual for the respective solid-phase reactions of the metal oxides and at the same temperatures as synthesis with comparable calcination processes using metal salts. The method therefore reduces the overall required energy for the nanoparticle synthesis. Thermogravimetric analysis shows that the thermolysis process of the eutectic melts in air occurs in one major step. The phase-pure spinel-type ferrite particles are thoroughly characterized by X-ray diffraction, diffuse-reflectance UV/Vis spectroscopy, and scanning electron microscopy. The properties of the obtained nanoparticles are shown to be comparable to those obtained by other methods, illustrating the potential of natural DESs for processing metal oxides.

  8. Microstructural and magnetic properties of thick ({>=}10 {mu}m) magnetron sputtered barium ferrite films

    Energy Technology Data Exchange (ETDEWEB)

    Dehlinger, A.S. [Universite de Lyon, Institut des Nanotechnologies de Lyon INL-UMR 5270, CNRS, INSA Lyon, Villeurbanne F-69621 (France); Le Berre, M., E-mail: martine.leberre@insa-lyon.f [Universite de Lyon, Institut des Nanotechnologies de Lyon INL-UMR 5270, CNRS, INSA Lyon, Villeurbanne F-69621 (France); Canut, B. [Universite de Lyon, Institut des Nanotechnologies de Lyon INL-UMR 5270, CNRS, INSA Lyon, Villeurbanne F-69621 (France); Chatelon, J.P. [DIOM, Universite Jean Monnet, Saint Etienne F-42023 (France); Albertini, D. [Universite de Lyon, Institut des Nanotechnologies de Lyon INL-UMR 5270, CNRS, INSA Lyon, Villeurbanne F-69621 (France); Perrot, S. [RADIALL, Voiron F-38500 (France); Givord, D. [Institut Louis Neel, UPR 5051, Grenoble F-38042 (France); Rousseau, J.J. [DIOM, Universite Jean Monnet, Saint Etienne F-42023 (France)

    2010-11-15

    This work focuses on the properties of 10-15 {mu}m thick barium M-type hexaferrite (BaFe{sub 12}O{sub 19} or BaM) films deposited by non-reactive RF magnetron sputtering on alumina substrates. High deposition rates were achieved through deposition at room temperature and operation at an RF power of 100 W. By varying sputtering gas pressure, the dc magnetic properties were correlated with structural, morphological and compositional properties obtained by X-ray diffraction (XRD), atomic force microscopy (AFM) and Rutherford backscattering spectrometry (RBS), respectively. A deposition pressure of P=3 Pa enables one to reach the best compromise between high deposition rate (0.75 {mu}m/h) and adequate crystallographic, stoichiometric and magnetostatic properties. Finally the gyromagnetic properties at high frequency were assessed through the characterization of coplanar isolator up to 60 GHz. As such, hexaferrite films prepared using this technique may offer opportunities for the next generation of self-biased planar microwave devices.

  9. Soft magnetic properties of MnZn ferrites prepared by powder injection moulding

    Directory of Open Access Journals (Sweden)

    Mitrović N.S.

    2012-01-01

    Full Text Available In this study, properties of soft-magnetic manganese zinc ferrite manufactured by powder injection moulding - PIM technology were presented. A powder consisting of Mn1- xZnxFe2O4 with small addition of hematite □-Fe2O3 was mixed with an organic binder (wax and thermoplastic to form ferrite feedstock. The ferrite feedstock was injected in a mould with a cavity shaped like a small cylinder with a hole on the main axis. Injection moulded samples were then solvent, thermally debinded and sintered in air atmosphere. Structure of sintered sample was characterized using X-ray diffractometry, scanning electron microscopy and thermomagnetic measurements. Magnetic properties were measured by hysteresis graph at different frequencies up to 1 kHz. Sintered sample contains a mixture of two phases Mn0.6Zn0.4Fe2O4 (68 wt. % and α-Fe2O3 (32 wt. %. The Curie temperature is TC ≈ 220°C for the green sample but after the heating up to 470°C, TC increase up to about 300°C. The high increase of normalized magnetic permeability of about 800 % was observed due to melting and burning of binder. The hysteresis loop of sintered MnZn ferrite toroidal cores has an R-shape with saturation of 0.44 T and remanence ratio of 0.49. The low value of coercivity (only 47 A/m was related to the presence of α-Fe2O3 crystalline phase and attained already optimum density (ρ ≈ 4.8 g/cm³ i.e. observed low level of porosity. Attained relative magnetic permeability μr ≈ 2000 as well as power losses Ps ≈ 21 W/kg for sintered sample (at 1 kHz; 0.39 T is in agreement with the MnZn ferrite commercial samples. [Projekat Ministarstva nauke Republike Srbije, br. OI 172057

  10. Preparation and Evaluation of Stomatitis Film Using Xyloglucan Containing Loperamide.

    Science.gov (United States)

    Kawano, Yayoi; Sasatsu, Masanaho; Mizutani, Ayako; Hirose, Kaoru; Hanawa, Takehisa; Onishi, Hiraku

    2016-06-01

    Stomatitis induced by radiation therapy or cancer chemotherapy is a factor in sleep disorders and/or eating disorders, markedly decreasing patient quality of life. In recent years, disintegrating oral films that are easy to handle have been developed; therefore, we focused on the formulation of these films. We prepared an adhesive film for the oral cavity using xyloglucan (Xylo), which is a water-soluble macromolecule. We used loperamide, which has been reported to relieve pain caused by stomatitis effectively, as a model drug in this study. Films were prepared from Xylo solutions (3% (w/w)) and hypromellose (HPMC) solutions (1% (w/w)). Xylo and HPMC solutions were mixed at ratios of 1 : 1, 2 : 1, or 3 : 1 for each film, and films 2×2 cm weighing 3 g were prepared and dried at 37°C for 24 h. Physicochemical properties such as strength, adhesiveness, disintegration behavior, and dissolution of loperamide from films were evaluated. Films prepared from Xylo solution alone had sufficient strength and mucosal adhesion. On the other hand, films prepared from a mixture of Xylo and HPMC were inferior to those made from Xylo, but showed sufficient strength and mucosal adhesion and were flexible and easy to handle. The films prepared in this study are useful as adhesion films in the oral cavity.

  11. Surface magnetic contribution in zinc ferrite thin films studied by element- and site-specific XMCD hysteresis-loops

    Science.gov (United States)

    Mendoza Zélis, P.; Pasquevich, G. A.; Salcedo Rodríguez, K. L.; Sánchez, F. H.; Rodríguez Torres, C. E.

    2016-12-01

    Element- and site-specific magnetic hysteresis-loops measurements on a zinc ferrite (ZnFe2O4) thin film were performed by X-ray magnetic circular dichroism. Results show that iron in octahedral and tetrahedral sites of spinel structure are coupled antiferromagnetically between them, and when magnetic field is applied the magnetic moment of the ion located at octahedral sites aligns along the field direction. The magnetic measurements reveal a distinctive response of the surface with in-plane anisotropy and an effective anisotropy constant value of 12.6 kJ/m3. This effective anisotropy is due to the combining effects of demagnetizing field and, volume and surface magnetic anisotropies KV =3.1 kJ/m3 and KS =16 μJ/m2.

  12. Preparation and Microstructure of Spinel Zinc Ferrite ZnFe_2O_4 by Co-precipitation Method

    Institute of Scientific and Technical Information of China (English)

    REN Ping; ZHANG Junxi; DENG Huiyong

    2009-01-01

    Spinel zinc ferrites ZnFe_2O)4,prepared by co-precipitation method using the zinc nitrate Zn(NO_3)_2·6H_2O and ferric nitrate Fe(NO_3)_3·2H_2O as the raw materials,were characterized by the thermo gravimetric analysis(TG)and differential scanning calorimeter(DSC),X-ray diffraction (XRD)and scanning electron microscope(SEM).The influence of synthesis conditions,such as Zn/Fe molar ratio,pH value,the sintering temperature and time,on the microstructures was detailedly in-vestigated.The relationships between the microstructures and the synthesis conditions were discussed.The results show that the pure spinel zinc ferrites ZnFe_2O_4 are formed when the Zn/Fe molar ratio is 1.05:2 at pH=8.5 or Zn/Fe molar ratio is 1:2 at Ph=9-10,and the precursors are sintered at 1100℃ for 4 h.Especially no other phases are observed when the Zn/Fe molar ratio is 1:2 at pH=10 and the precursor is sintered above 700 ℃for 4h.The higher sintering temperature and longer sintering time contribute to grain growth.

  13. Adsorption of cobalt ferrite nanoparticles within layer-by-layer films: a kinetic study carried out using quartz crystal microbalance.

    Science.gov (United States)

    Alcantara, Gustavo B; Paterno, Leonardo G; Afonso, André S; Faria, Ronaldo C; Pereira-da-Silva, Marcelo A; Morais, Paulo C; Soler, Maria A G

    2011-12-28

    The paper reports on the successful use of the quartz crystal microbalance technique to assess accurate kinetics and equilibrium parameters regarding the investigation of in situ adsorption of nanosized cobalt ferrite particles (CoFe(2)O(4)--10.5 nm-diameter) onto two different surfaces. Firstly, a single layer of nanoparticles was deposited onto the surface provided by the gold-coated quartz resonator functionalized with sodium 3-mercapto propanesulfonate (3-MPS). Secondly, the layer-by-layer (LbL) technique was used to build multilayers in which the CoFe(2)O(4) nanoparticle-based layer alternates with the sodium sulfonated polystyrene (PSS) layer. The adsorption experiments were conducted by modulating the number of adsorbed CoFe(2)O(4)/PSS bilayers (n) and/or by changing the CoFe(2)O(4) nanoparticle concentration while suspended as a stable colloidal dispersion. Adsorption of CoFe(2)O(4) nanoparticles onto the 3-MPS-functionalized surface follows perfectly a first order kinetic process in a wide range (two orders of magnitude) of nanoparticle concentrations. These data were used to assess the equilibrium constant and the adsorption free energy. Alternatively, the Langmuir adsorption constant was obtained while analyzing the isotherm data at the equilibrium. Adsorption of CoFe(2)O(4) nanoparticles while growing multilayers of CoFe(2)O(4)/PSS was conducted using colloidal suspensions with CoFe(2)O(4) concentration in the range of 10(-8) to 10(-6) (moles of cobalt ferrite per litre) and for different numbers of cycles n = 1, 3, 5, and 10. We found the adsorption of CoFe(2)O(4) nanoparticles within the CoFe(2)O(4)/PSS bilayers perfectly following a first order kinetic process, with the characteristic rate constant growing with the increase of CoFe(2)O(4) nanoparticle concentration and decreasing with the rise of the number of LbL cycles (n). Additionally, atomic force microscopy was employed for assessing the LbL film roughness and thickness. We found the film

  14. Synthesis, structural investigation and magnetic properties of Zn{sup 2+} substituted cobalt ferrite nanoparticles prepared by the sol–gel auto-combustion technique

    Energy Technology Data Exchange (ETDEWEB)

    Raut, A.V., E-mail: nano9993@gmail.com [Vivekanand Arts and Sardar Dalipsingh Commerce and Science College, Aurangabad, 431004 Maharastra (India); Barkule, R.S.; Shengule, D.R. [Vivekanand Arts and Sardar Dalipsingh Commerce and Science College, Aurangabad, 431004 Maharastra (India); Jadhav, K.M., E-mail: drjadhavkm@gmail.com [Department of Physics, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad, 431004 Maharastra (India)

    2014-05-01

    Structural morphology and magnetic properties of the Co{sub 1−x}Zn{sub x}Fe{sub 2}O{sub 4} (0.0≤x≥1.0) spinel ferrite system synthesized by the sol–gel auto-combustion technique using nitrates of respective metal ions have been studied. The ratio of metal nitrates to citric acid was taken at 1:3. The as prepared powder of cobalt zinc ferrite was sintered at 600 °C for 12 h after TG/DTA thermal studies. Compositional stoichiometry was confirmed by energy dispersive analysis of the X-ray (EDAX) technique. Single phase cubic spinel structure of Co–Zn nanoparticles was confirmed by XRD data. The average crystallite size (t), lattice constant (a) and other structural parameters of zinc substituted cobalt ferrite nanoparticles were calculated from XRD followed by SEM and FTIR. It is observed that the sol–gel auto-combustion technique has many advantages for the synthesis of technologically applicable Co–Zn ferrite nanoparticles. The present investigation clearly shows the effect of the synthesis method and possible relation between magnetic properties and microstructure of the prepared samples. Increase in nonmagnetic Zn{sup 2+} content in cobalt ferrite nanoparticles is followed by decrease in n{sub B}, M{sub s} and other magnetic parameters. Squareness ratio for the Co-ferrite was 1.096 at room temperature. - Highlights: • Co–Zn nanoparticles are prepared by sol–gel auto-combustion method. • Structural properties were characterized by XRD, SEM, and FTIR. • Compositional stoichiometry was confirmed by EDAX analysis. • Magnetic parameters were measured by the pulse field hysteresis loop technique.

  15. Mechanical properties of 9Cr–1W reduced activation ferritic martensitic steel weldment prepared by electron beam welding process

    Energy Technology Data Exchange (ETDEWEB)

    Das, C.R., E-mail: chitta@igcar.gov.in [Indira Gandhi Center for Atomic Research, Kalpakkam 603102 (India); Albert, S.K. [Indira Gandhi Center for Atomic Research, Kalpakkam 603102 (India); Sam, Shiju [Institute for Plasma Research, Gandhinagar (India); Mastanaiah, P. [Defense Research and Development Laboratory, Hyderabad (India); Chaitanya, G.M.S.K.; Bhaduri, A.K.; Jayakumar, T. [Indira Gandhi Center for Atomic Research, Kalpakkam 603102 (India); Murthy, C.V.S. [Defense Research and Development Laboratory, Hyderabad (India); Kumar, E. Rajendra [Institute for Plasma Research, Gandhinagar (India)

    2014-11-15

    Highlights: • Width of HAZ is smaller in the 9Cr–1W RAFM weldment prepared by EB process compared to that reported for TIG weldments in literature. • Weld joint is stronger than that of the base metal. • Toughness of weld metal prepared by EB welding process is comparable to that (in PWHT condition) prepared by TIG process. • DBTT of as-welded 9Cr–1W RAFM weldment prepared by EB process is comparable to that reported for TIG weld metal in PWHT condition. - Abstract: Microstructure and mechanical properties of the weldments prepared from 9Cr–1W reduced activation ferritic martensitic (RAFM) steel using electron beam welding (EBW) process were studied. Microstructure consists of tempered lath martensite where precipitates decorating the boundaries in post weld heat treated (PWHT) condition. Lath and precipitate sizes were found to be finer in the weld metal than in base metal. Accordingly, hardness of the weld metal was found to be higher than the base metal. Tensile strength of the cross weldment specimen was 684 MPa, which was comparable with the base metal tensile strength of 670 MPa. On the other hand, DBTT of 9Cr–1W weld metal in as-welded condition is similar to that reported for TIG weld metal in PWHT condition.

  16. Structure and 57Fe conversion electron M(o)ssbauer spectroscopy study of Mn-Zn ferrite nanocrystal thin films by electroless plating in aqueous solution

    Institute of Scientific and Technical Information of China (English)

    SUN JianRong; WANG XueWen; LIU JinHong; WANG JianBo; LI FaShen

    2008-01-01

    Mn1-xZnxFe2O4 thin films with various Zn contents and of different thickness were synthesized on glass substrates directly by electroless plating in aqueous solution at 90℃ without heat treatment. The Mn-Zn ferrite films have a single spinel phase structure and well-crystallized columnar grains growing per-pendicularly to the substrates. The results of conversion electron 57Fe Mossbauer spectroscopy (CEMS) indicate that the cation distribution of Mn-xZnxFe2O4 ferrite nanocrystal thin films fabricated by elec-troless plating is different from the bulk materials' and a great quantity of Fe3+ ions are still present on A sites for x>0.5. When the Zn content of the films increases, Fe3+ ions in the films transfer from A sites to B sites and the hyperfine magnetic field reduces, suggesting that Zn2+ has strong chemical affinity towards the A sites. On the other side, with the increase of the thickness of the films, Fe3+ ions, at B sites in the spinel structure, increase and the array of magnetic moments no longer lies in the thin film plane completely. At x=0.5, Hc and Ms of Mn1-xZnxFe2O4 thin films show a minimum of 3.7 kA/m and a maximum of 419.6 kA/m, respectively.

  17. Mössbauer effect studies and X-ray diffraction analysis of cobalt ferrite prepared in powder form by thermal decomposition method

    Indian Academy of Sciences (India)

    M D Joseph Sebastian; B Rudraswamy; M C Radhakrishna; Ramani

    2003-08-01

    Cobalt ferrite (Co$_x$Fe$_{3–x}$O4) is prepared in powder form by thermal decomposition of iron and cobalt salts and is analysed by X-ray diffraction and Mössbauer spectroscopic techniques. The variation of Mössbauer parameters, lattice parameters and crystallite size of the products formed with variation in the composition of Fe and Co ratios are studied. The studies confirm the formation of nano-size cobalt ferrite particles with defect structure and it is found to be maximum for the Fe : Co = 60 : 40 ratio of the initial precursor oxides.

  18. Chitosan–silver oxide nanocomposite film: Preparation and antimicrobial activity

    Indian Academy of Sciences (India)

    Shipra Tripathi; G K Mehrotra; P K Dutta

    2011-02-01

    The chitosan–silver oxide encapsulated nanocomposite film was prepared by solution casting method. The prepared film was characterized by FTIR, scanning electron microscopy (SEM), thermal studies, and UV-Vis spectroscopy. The elemental composition of the film was studied by energy dispersive X-ray analysis (EDAX). The antibacterial activity of the composite film against pathogenic bacteria viz. Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Pseudomonas aeruginosa was measured by agar diffusion method. Our observations suggest that chitosan as biomaterial based nanocomposite film containing silver oxide has an excellent antibacterial ability for food packaging applications.

  19. Super-hydrophobic film prepared on zinc as corrosion barrier

    Energy Technology Data Exchange (ETDEWEB)

    Wang Peng [Key Lab of Corrosion Science, Shandong Province, Institute of Oceanology, Chinese Academy of Sciences, 7 Naihai Road, Qingdao 266071 (China); Zhang Dun, E-mail: Zhangdun@qdio.ac.c [Key Lab of Corrosion Science, Shandong Province, Institute of Oceanology, Chinese Academy of Sciences, 7 Naihai Road, Qingdao 266071 (China); Qiu Ri [Key Lab of Corrosion Science, Shandong Province, Institute of Oceanology, Chinese Academy of Sciences, 7 Naihai Road, Qingdao 266071 (China); Graduate School of the Chinese Academy of Sciences, 19 (Jia) Yuquan Road, Beijing 100039 (China); Hou Baorong [Key Lab of Corrosion Science, Shandong Province, Institute of Oceanology, Chinese Academy of Sciences, 7 Naihai Road, Qingdao 266071 (China)

    2011-06-15

    Research highlights: {yields} Super-hydrophobic film was prepared on zinc surface. {yields} The air trapped in film can dramatically improve the anti-corrosion property. {yields} The air trapped behaves as dielectric for a pure parallel plate capacitor. {yields} The air enhances the contribution of film to the anti-corrosion property. {yields} Without the help of air, the film itself can only present feeble inhibition effect. - Abstract: Potentiostatic electrolysis was carried out to prepare super-hydrophobic film on the surface of metallic zinc. The resultant film was examined by field emission scanning electron microscopy, Fourier transform infrared spectroscopy, electrochemical measurements, and contact angle test. The super-hydrophobic property of the film results from the air trapped among the sheets of zinc tetradecanoate. This air behaves as a dielectric for a pure parallel plate capacitor, thereby inhibiting electron transfer between the electrolyte and the substrate. The air can also enhance the contribution of the film itself to protection performance.

  20. Structural and magnetic properties of zinc- and aluminum-substituted cobalt ferrite prepared by co-precipitation method

    Indian Academy of Sciences (India)

    S T Alone; K M Jadhav

    2008-01-01

    Spinal ferrites having the general formula Co1-ZnFe2-AlO4 ( = 0.0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6) were prepared using the wet chemical co-operation technique. The samples were annealed at 800°C for 12 h and were studied by means of X-ray diffraction, magnetization and low field AC susceptibility measurements. The X-ray analysis showed that all the samples had single-phase cubic spinel structure. The variation of lattice constant with Zn and Al concentration deviates from Vegard's law. The saturation magnetization and magneton number B measured at 300 K using high field hysteresis loop technique decreases with increasing , suggesting decrease in ferrimagnetic behaviour. Curie temperature C deduced from AC susceptibility data decreases with , suggesting a decrease in ferrimagnetic behaviour.

  1. Preparation and Magnetic Properties of SrFe12O19 Ferrites Suitable for Use in Self-Biased LTCC Circulators

    Science.gov (United States)

    Peng, Long; Hu, Yue-Bin; Guo, Cheng; Li, Le-Zhong; Wang, Rui; Hu, Yun; Tu, Xiao-Qiang

    2015-01-01

    Strontium ferrites with different Bi2O3 content are prepared by the solid phase method, and their magnetic properties are investigated primarily. The Bi2O3 additive and sintering temperature separately exhibit a strong effect on the sintering density, crystal structure, and magnetic properties of the ferrites. As to the ferrites with 3 wt% Bi2O3, the relatively high sintering density ρs, saturation magnetization Ms, and intrinsic coercivity Hci can be obtained at a low sintering temperature of 900°C even much lower. Furthermore, the effective magnetic anisotropy constant Keff and magnetic anisotropy field Ha of the ferrites are calculated from the magnetization curve by the law of approach to saturation. It is suggested that the low-temperature sintered SrFe12O19 ferrites with Ms of 285.6 kA/m and Ha of 1564.6 kA/m possess a significant potentiality for applying in the self-biased low-temperature co-fired ceramics circulators from 34 to 40 GHz.

  2. Characterization and Magnetic Properties of Nickel Ferrite Nanoparticles Prepared by Ball Milling Technique

    Institute of Scientific and Technical Information of China (English)

    G.Nabiyouni; M.Jafari Fesharaki; M.Mozafari; J.Amighian

    2010-01-01

    @@ Nickel ferrite nanoparicles with various grain sizes are synthesized using annealing treatment followed by ball milling of its bulk component materials.Commercially available nickel and iron oxide powders are first mixed,and then annealed at 1100℃ in an oxygen environment furnace and for 3h.The samples are then milled for different times in an SPEX mill.X-ray diffraction pattern indicates that in this stage the sample is single phase.The average grain size is estimated by scanning electron microscopy(SEM)and x-ray diffraction techniques.Magnetic behavior of the sample at room temperature is studied using a superconducting quantum interference device(SQUID).The Curie temperature of the powders is measured by an LCR meter unit.The x-ray diffraction patterns clearly indicate that increasing the milling time leads to a decrease in the grain size and consequently leads to a decrease in the saturation magnetization as well as the Curie temperatures.This result is attributed to the spin-glass-like surface layer on the nanocrystalline nickel ferrite with a ferrimagnetically aligned core.

  3. Development of cobalt ferrite powder preparation employing the sol-gel technique and its structural characterisation

    Directory of Open Access Journals (Sweden)

    Olabi A.G.

    2010-06-01

    Full Text Available This work focuses on the development of a method to make nano cobalt ferrite powder using a solgel process. A particular emphasis is devoted to the understanding of the role of the chemical parameters involved in the solgel technique, and of the heat treatment on the structures and morphologies of the materials obtained. Several samples of cobalt ferrite powder were obtained by varying the initial parameters of the process in addition to the heat treatment temperature. Xray diffraction and scanning electron microscopy were used to identify the structure and morphology of samples demonstrating the influence of the initial parameters. DTA/TGA was carried out on one sample to identify important reaction temperatures during the heat treatment. The average particle size, as estimated for one sample by the full width at half maximum (FWHM of the strongest Xray diffraction (XRD peak, was found to be about 45 nm. It has been found that the chelating agent and the crosslinker have a critical influence on the resultant structure, the particle size and the particle size distribution.

  4. Study of bagasse/tapioca starch film preparation and characterization

    Science.gov (United States)

    Chen, Yanyang; Wei, Xiaoyi; Chang, Gang; Fu, Tiaokun; Cui, Lihong; Li, Jihua

    2017-06-01

    Bagasse/tapioca starch films (BT) were prepared with various contents of bagasse (10, 20, 30, 40 and 50 wt% based on tapioca starch), and the effect of bagasse concentration was studied by the performance of the BT films. Then, the BT films characteristics were analyzed using the instruments about ultraviolet spectrophotometer (US), SEM, TGA and XRD. The dispersion of the bagasse became better with bagasse concentration increasing, the intermolecular hydrogen bonding became stronger while the transparency values of the films decreased.

  5. Effect of preparation conditions on Nickel Zinc Ferrite nanoparticles: A comparison between sol–gel auto combustion and co-precipitation methods

    Directory of Open Access Journals (Sweden)

    Manju Kurian

    2016-09-01

    Full Text Available The experimental conditions used in the preparation of nano crystalline mixed ferrite materials play an important role in the particle size of the product. In the present work a comparison is made on sol–gel auto combustion methods and co-precipitation methods by preparing Nickel Zinc Ferrite (Ni0.5Zn0.5Fe2O4 nano particles. The prepared ferrite samples were calcined at different temperatures and characterized by using standard methods. X-ray diffraction analysis indicated the formation of single phase ferrite nanoparticles for samples calcined at 500 °C. The lattice parameter range of 8.32–8.49 Å confirmed the cubic spinel structure. Average crystallite size estimated from X-ray diffractogram was found to be between 17 and 40 nm. The IR spectra showed two main absorption bands, the high frequency band ν1 around 600 cm−1 and the low frequency band ν2 around 400 cm−1 arising from tetrahedral (A and octahedral (B interstitial sites in the spinel lattice. TEM pictures showed particles in the nanometric range confirming the XRD data. The studies revealed that the sol–gel auto combustion method was superior to the co-precipitation method for producing single phase nano particles with smaller crystallite size.

  6. Silk fibroin/pullulan blend films: Preparation and characterization

    Science.gov (United States)

    Shivananda, C. S.; Rao, B. Lakshmeesha; Madhukumar, R.; Sarojini, B. K.; Somashekhar, R.; Asha, S.; Sangappa, Y.

    2016-05-01

    In this work silk fibroin/pullulan blend films have been prepared by solution casting method. The blend films were examined for structural, and thermal properties using X-ray diffraction (XRD), thermogravimatric (TGA) and differential scanning calorimetry (DSC) analysis. The XRD results indicate that with the introduction of pullulan, the interaction between SF and pullulan in the blend films induced the conformation transition of SF films and amorphous phase increases with increasing pullulan ratio. The thermal properties of the blend films were improved significantly in the blend films.

  7. Silk fibroin/pullulan blend films: Preparation and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Shivananda, C. S.; Rao, B. Lakshmeesha; Madhukumar, R.; Asha, S. [Department of Studies in Physics, Mangalore University, Mangalagangotri – 574 199 (India); Sarojini, B. K. [Department of Industrial Chemistry, Mangalore University, Mangalagangotri, Mangalore –574 199 (India); Somashekhar, R. [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore – 570 006 (India); Sangappa, Y., E-mail: syhalabhavi@yahoo.co.in [Department of Studies in Physics, Mangalore University, Mangalagangotri – 574 199 (India); School of Material Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332 (United States)

    2016-05-23

    In this work silk fibroin/pullulan blend films have been prepared by solution casting method. The blend films were examined for structural, and thermal properties using X-ray diffraction (XRD), thermogravimatric (TGA) and differential scanning calorimetry (DSC) analysis. The XRD results indicate that with the introduction of pullulan, the interaction between SF and pullulan in the blend films induced the conformation transition of SF films and amorphous phase increases with increasing pullulan ratio. The thermal properties of the blend films were improved significantly in the blend films.

  8. Prepared and Electromagnetic Properties of La Doped Strontium Ferrite/Polymer Composite%镧掺杂锶铁氧体/聚苯胺纳米复合材料的制备及电磁性能

    Institute of Scientific and Technical Information of China (English)

    翟青霞; 黄英

    2011-01-01

    To compare the electromagnetic properties of La-doped strontium ferrites nanocomposite in different form, strontium ferrites particle doped with La were synthesized by sol-gel, strontium ferrite/PANI nanocomposites were prepared by in situ polymerization method, La doped nano-strontium ferrite/PSS film and SrLa0.4Fe11.6O,9/PSS/PANI mult-layers film were prepared by electrostatic self-assembly technique. The structure, morphology and ferromagnetic property of ferrite particle and nanocomposites were characterized by X-ray powder diffractometer (XRD) , Fourier transform infrared spectra (FTIR) , Transmission electron microscope (TEM) , X-ray photoelectron spectrum ( XPS) , Magnetic vector network analyzer and vibrating sample magnetometer ( VSM ) . The results indicate that at 9.21GHz,the strength of microwave absorption properties of all is; ( SrLa0.4Fe11.6O19/PSS/PANI)g multi-layer film > SrLa0.4Fe11.6 O19/PANI particle > SrLa0.4Fe11.6O19 particle, (SrLa0 4Fen 6OI9/PSS/PANI)8 multi-layer film has higher saturation magnetization Mt and coercivity Hc as compared with the particle SrFe12O19 and SrFe12O19/ PANI composite materials. (SrLa0.4Fe11.6O19/PSS/PANI)g multi-layer film has fine electromagnetic performance.%为了比较不同形态的镧掺杂纳米锶铁氧体复合材料电磁性能的优劣,分别以溶胶-凝胶法制备了稀土镧掺杂纳米锶铁氧体( SrLa0.4Fe11.6O19)颗粒、原位复合技术制备了镧掺杂锶铁氧体/聚苯胺(SrLa0.4Fe11.6 O19/PANI)纳米复合颗粒,静电自组装法制备了镧掺杂锶铁氧体/聚苯乙烯磺酸钠( SrLa0.4Fe11.6O19/PSS)20、镧掺杂锶铁氧体/聚苯乙烯磺酸钠/聚苯胺( SrLa0.4Fe11.6 O19/PSS/PANI)8纳米复合多层膜.用XRD,FTIR,FETEM,XPS,矢量网络分析,VSM研究了镧掺杂锶铁氧体/聚苯胺纳米复合材料结构和性能.结果表明:在9.21GHz附近,材料的损耗角正切大小排序为:( SrLa0.4Fe11.6 O19/PSS/PANI)8复合多层膜>SrLa0.4 Fe11.6O19/PANI复合颗粒>SrLa0

  9. Surface magnetic contribution in zinc ferrite thin films studied by element- and site-specific XMCD hysteresis-loops

    Energy Technology Data Exchange (ETDEWEB)

    Mendoza Zélis, P.; Pasquevich, G.A. [IFLP-CCT-La Plata-CONICET and Departamento de Física, Facultad de Ciencias Exactas, C. C. 67, Universidad Nacional de La Plata, 1900 La Plata (Argentina); Departamento de Ciencias Básicas, Facultad de Ingeniería, Universidad Nacional de La Plata, 1900 La Plata (Argentina); Salcedo Rodríguez, K.L.; Sánchez, F.H. [IFLP-CCT-La Plata-CONICET and Departamento de Física, Facultad de Ciencias Exactas, C. C. 67, Universidad Nacional de La Plata, 1900 La Plata (Argentina); Rodríguez Torres, C.E., E-mail: torres@fisica.unlp.edu.ar [IFLP-CCT-La Plata-CONICET and Departamento de Física, Facultad de Ciencias Exactas, C. C. 67, Universidad Nacional de La Plata, 1900 La Plata (Argentina)

    2016-12-01

    Element- and site-specific magnetic hysteresis-loops measurements on a zinc ferrite (ZnFe{sub 2}O{sub 4}) thin film were performed by X-ray magnetic circular dichroism. Results show that iron in octahedral and tetrahedral sites of spinel structure are coupled antiferromagnetically between them, and when magnetic field is applied the magnetic moment of the ion located at octahedral sites aligns along the field direction. The magnetic measurements reveal a distinctive response of the surface with in-plane anisotropy and an effective anisotropy constant value of 12.6 kJ/m{sup 3}. This effective anisotropy is due to the combining effects of demagnetizing field and, volume and surface magnetic anisotropies K{sub V} =3.1 kJ/m{sup 3} and K{sub S} =16 μJ/m{sup 2}. - Highlights: • Surface magnetic response in ZnFe{sub 2}O{sub 4} film (thickness t ∼57 nm) by XMCD is studied. • Measurements of magnetic moment vs. applied field cycles via XMCD are presented. • Fe{sup 3+} at A- and B-sites are coupled antiferromagnetically between them. • A distinctive response of the surface with in-plane magnetic anisotropy is determined. • Volume and surface magnetic anisotropy are determined: 3.1 kJ/m{sup 3} and 16 μJ/m{sup 2}.

  10. Preparation and characterization chemistry of nano-crystalline Ni-Cu-Zn ferrite

    Energy Technology Data Exchange (ETDEWEB)

    Hashim, Mohd, E-mail: md.hashim09@gmail.com [Department of Applied Physics, Aligarh Muslim University, Aligarh 202002 (India); Alimuddin [Department of Applied Physics, Aligarh Muslim University, Aligarh 202002 (India); Shirsath, Sagar E. [Spin Device Technology Centre, Faculty of Engineering, Shinshu University, Nagano 380-8553 (Japan); Kumar, Shalendra [Department of Physics, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); Kumar, Ravi [Centre for Material Science Engineering, National Institute of Technology, Hamirpur, HP (India); Roy, Aashis S. [Department of Materials Engineering, Indian Institute of Science, Bangalore, Karnataka (India); Shah, Jyoti; Kotnala, R.K. [National Physical Laboratory (CSIR), Dr. K.S. Krishnan Road, New Delhi 110012 (India)

    2013-02-05

    Highlights: Black-Right-Pointing-Pointer Single phase Ni{sub 0.5}Cu{sub 0.25}Zn{sub 0.25}Fe{sub 2-x}In{sub x}O{sub 4} ferrites were synthesized by citrate-nitrate precursor auto combustion. Black-Right-Pointing-Pointer Magnetic properties decreased due to the substitution of In{sup 3+} ions. Black-Right-Pointing-Pointer Dielectric properties decreased with increase in frequency. Black-Right-Pointing-Pointer This composition can be used for multilayer chip inductor (MLCI) applications. - Abstract: In submitted research; nanocrystalline powders having elements Ni{sub 0.5}Cu{sub 0.25}Zn{sub 0.25}Fe{sub 2-x}In{sub x}O{sub 4} with varied amounts of indium (x = 0.0, 0.1, 0.2, 0.3 and 0.4) were grown-up by modified citrate to nitrate alchemy. The realism of single phase cubic spinel creation of the synthesized ferrite samples was studied by the DTA-TGA, XRD, SEM, EDX, FT-IR, VSM and dielectric measurements. SEM was applied to inspect the morphological variations and EDX was used to determine the compositional mass ratios. The studies on the dielectric constant ({epsilon} Prime ), dielectric loss ({epsilon} Double-Prime ), loss tangent (tan {delta}), ac conductivity ({sigma}{sub ac}), resistive and reactive parts of the impedance analysis (Z' and Z') at room temperature were also carried out. The saturation magnetizations (Ms) were determined using the vibrating sample magnetometer (VSM). Ms. decreased with the increase In{sup 3+} doping content, as Fe{sup 3+} of 5{mu}{sub B} ions are replaced by In{sup 3+} of 0 {mu}{sub B} ions.

  11. Comparison of the Sol-gel Method with the Coprecipitation Technique for Preparation of Hexagonal Barium Ferrite

    Institute of Scientific and Technical Information of China (English)

    WANG Jing-ping; LIU Ying; ZHANG Mi-lin; QIAO Ying-jie; XIA Tian

    2008-01-01

    Hexagonal barium ferrite BaFe12O19 particles were prepared by sol-gel and coprecipitation methods,respectively.The composition of the so-obtained materials was investigated by means of XRD.By the sol-gel method,non-anticipated intermediate crystalline phases,such as γ-Fe2O3,α-Fe2O3,BaCO3,and BaFe2O4 etc.,were formed with the delay of the formation of BaFe12O19.The formation of single phase BaFe12O19 required calcination at 850 ℃ for 4 h.On the other hand,using copreeipitation technique,amorphous hydroxide precursor was directly transferred into BaFe12O19 almost without the formation of intermediate crystalline phases.BaFe12O19 was prepared by calcining at 700 ℃ for 3 h.The results were confirmed by ESEM and VSM analyses.Based on the already reported results and the observed results in this study,it can be concluded that the coprecipitaion technique is easier to control than the sol-gel method for preparation of BaFe12O19 at a low temperature.

  12. Study of the preparation of NI–Mn–Zn ferrite using spent NI–MH and alkaline Zn–Mn batteries

    Energy Technology Data Exchange (ETDEWEB)

    Xi, Guoxi, E-mail: xuhuidao1983@hotmail.com; Xi, Yuebin; Xu, Huidao, E-mail: xuhuidao1983@163.com; Wang, Lu

    2016-01-15

    Magnetic nanoparticles of Ni–Mn–Zn ferrite have been prepared by a sol–gel method making use of spent Ni–MH and Zn–Mn batteries as source materials. Characterization by X-ray diffraction was carried out to study the particle size. The presence of functional groups was identified by Fourier transform infrared spectroscopy. From studies by thermogravimetry and differential scanning calorimetry, crystallization occurred at temperatures above 560 °C. The magnetic properties of the final products were found to be directly influenced by the average particle size of the product. The M{sub s} values increase and the H{sub c} values decrease as the size of the Ni–Mn–Zn ferrite particles increases. - Highlights: • Ni–Mn–Zn ferrites could be prepared using spentbatteries as raw materials. • This work could provide an environmentally friendly process to recycle spent batteries. • The process could reduce cost and secondary pollution of spent batteries recycling. • The magnetic property of the ferrite could be controlled by changing the temperature.

  13. SiO{sub 2} modified Co-ferrite with high coercivity

    Energy Technology Data Exchange (ETDEWEB)

    Ding, J. E-mail: masdingj@nus.edu.sg; Gong, H.; Melaka, R.; Wang, S.; Shi, Y.; Chen, Y.J.; Phuc, N.X

    2001-05-01

    Magnetic and Moessbauer measurements have shown that 1-2 wt% of SiO{sub 2} were solved in the CoFe{sub 2}O{sub 4} structure after mechanical milling and subsequent heat treatment. Coercivity values up to 3.5 kOe were measured for CoFe{sub 2}O{sub 4}/SiO{sub 2} powders. High coercivities were also achieved in SiO{sub 2} doped Co-ferrite thin films prepared by sputtering technique. The Co-ferrite thin film deposited on silicon wafer using a 5 wt%-SiO{sub 2}/Co-ferrite target possessed a coercivity of 7.4 kOe, which is the highest value in Co-ferrite and spinel materials according to our knowledge.

  14. Preparation and properties of antimony thin film anode materials

    Institute of Scientific and Technical Information of China (English)

    SU Shufa; CAO Gaoshao; ZHAO Xinbing

    2004-01-01

    Metallic antimony thin films were deposited by magnetron sputtering and electrodeposition. Electrochemical properties of the thin film as anode materials for lithium-ion batteries were investigated and compared with those of antimony powder. It was found that both magnetron sputtering and electrodeposition are easily controllable processes to deposit antimony films with fiat charge/discharge potential plateaus. The electrochemical performances of antimony thin films, especially those prepared with magnetron sputtering, are better than those of antimony powder. The reversible capacities of the magnetron sputtered antimony thin film are above 400 mA h g-1 in the first 15 cycles.

  15. Perpendicular magnetic anisotropy in epitaxially strained cobalt-ferrite (001) thin films

    Energy Technology Data Exchange (ETDEWEB)

    Yanagihara, H., E-mail: yanagiha@bk.tsukuba.ac.jp; Utsumi, Y.; Niizeki, T., E-mail: t-niizeki@imr.tohoku.ac.jp; Inoue, J.; Kita, Eiji [Institute of Applied Physics, University of Tsukuba, Tsukuba 305-8573 (Japan)

    2014-05-07

    We investigated the dependencies of both the magnetization characteristics and the perpendicular magnetic anisotropy of Co{sub x}Fe{sub 3–x}O{sub 4}(001) epitaxial films (x = 0.5 and 0.75) on the growth conditions of the reactive magnetron sputtering process. Both saturation magnetization and the magnetic uniaxial anisotropy constant K{sub u} are strongly dependent on the reactive gas (O{sub 2}) flow rate, although there is little difference in the surface structures for all samples observed by reflection high-energy electron diffraction. In addition, certain dead-layer-like regions were observed in the initial stage of the film growth for all films. Our results suggest that the magnetic properties of Co{sub x}Fe{sub 3–x}O{sub 4} epitaxial films are governed by the oxidation state and the film structure at the vicinity of the interface.

  16. Microstructure, electrical property and nonstoichiometry of light enhanced plating (LEP) ferrite film

    CERN Document Server

    Kim, D; Kim, Y I

    1998-01-01

    A magnetic film was deposited on a slide glass substrate from aqueous solutions of FeCl sub 2 and NaNO sub 2 at 363K. XRD analysis showed that the film was polycrystalline magnetite (Fe sub 3 sub ( sub 1 sub -delta sub ) O sub 4 without impurity. The lattice constant was 0.8390 nm. Moessbauer spectrum of the film could be deconvoluted by the following parameters: isomer shifts for tetrahedral (T sub d) and octahedral (O sub h) sites are 0.28 and 0.68 mm/s, respectively, and corresponding magnetic hyperfine fields are 490 and 458 kOe, respectively. The estimated chemical formula of the film by the peak intensity of Mossbauer spectrum was Fe sub 2 sub . sub 9 sub 5 O sub 4. Low temperature transition of the magnetite (Verwey transition) was not detected in resistivity measurement of the film. Properties of the film were discussed with those of pressed pellet and single crystal of synthetic magnetites. On the surface of the film, magnetite particles of about 0.2 mu m in diameter were identified by noncontact ato...

  17. Preparation of Modified Films with Protein from Grouper Fish

    Directory of Open Access Journals (Sweden)

    M. A. Valdivia-López

    2016-01-01

    Full Text Available A protein concentrate (PC was obtained from Grouper fish skin and it was used to prepare films with different amounts of sorbitol and glycerol as plasticizers. The best performing films regarding resistance were then modified with various concentrations of CaCl2, CaSO4 (calcium salts, and glucono-δ-lactone (GDL with the purpose of improving their mechanical and barrier properties. These films were characterized by determining their mechanical properties and permeability to water vapor and oxygen. Formulations with 5% (w/v protein and 75% sorbitol and 4% (w/v protein with a mixture of 15% glycerol and 15% sorbitol produced adequate films. Calcium salts and GDL increased the tensile fracture stress but reduced the fracture strain and decreased water vapor permeability compared with control films. The films prepared represent an attractive alternative for being used as food packaging materials.

  18. Preparation of Modified Films with Protein from Grouper Fish

    Science.gov (United States)

    Tecante, A.; Granados-Navarrete, S.; Martínez-García, C.

    2016-01-01

    A protein concentrate (PC) was obtained from Grouper fish skin and it was used to prepare films with different amounts of sorbitol and glycerol as plasticizers. The best performing films regarding resistance were then modified with various concentrations of CaCl2, CaSO4 (calcium salts), and glucono-δ-lactone (GDL) with the purpose of improving their mechanical and barrier properties. These films were characterized by determining their mechanical properties and permeability to water vapor and oxygen. Formulations with 5% (w/v) protein and 75% sorbitol and 4% (w/v) protein with a mixture of 15% glycerol and 15% sorbitol produced adequate films. Calcium salts and GDL increased the tensile fracture stress but reduced the fracture strain and decreased water vapor permeability compared with control films. The films prepared represent an attractive alternative for being used as food packaging materials. PMID:27597950

  19. Magnetocaloric effect in Ni-Zn ferrite nanoparticles prepared by using solution combustion

    Energy Technology Data Exchange (ETDEWEB)

    Lee, K. D.; Kambale, R. C.; Hur, N. [Inha University, Incheon (Korea, Republic of)

    2014-12-15

    Ni{sub x}Zn{sub 1-x}Fe{sub 2}O{sub 4} (x = 0.2 and 0.3) ferrite nanoparticles with sizes ranging from 65 to 70 nm were synthesized employing the solution combustion route. The magnetocaloric behavior was investigated within the 50 K ≤ T ≤ 400 K range of temperatures (T). The entropy change (ΔS) and the adiabatic temperature change (ΔT) were derived from magnetization (M) and specific heat (C{sub P} ) measurements. Both compositions exhibited broad peaks for the isothermal entropy change. The magnetic field (H)-dependent ΔT was analyzed within the mean-field approximation scheme, and the observed magnetocaloric properties of the nanoparticle samples were compared with those of a bulk sample. Our study suggests that the magnetocaloric properties of magnetic oxides strongly depend on the particle size; thus, particle size should be considered as a key tuning parameter in the optimization of magnetic refrigeration.

  20. Structural, magnetic and electrical properties of cobalt ferrites prepared by the sol-gel route

    Energy Technology Data Exchange (ETDEWEB)

    Gul, I.H. [Thermal Physics Laboratory, Department of Physics, Quaid-i-Azam University, Islamabad 45320 (Pakistan)], E-mail: iftikhar_qau@yahoo.com; Maqsood, A. [Thermal Physics Laboratory, Department of Physics, Quaid-i-Azam University, Islamabad 45320 (Pakistan)], E-mail: tpl.qau@usa.net

    2008-10-06

    Nanosized cobalt ferrites having the general formula CoFe{sub 2-x}Al{sub x}O{sub 4} (for x = 0.00, 0.25, 0.50) have been synthesized by the sol-gel route. The effect of Al{sup 3+} ions on structural, Curie temperature, DC electrical resistivity and dielecltric properties are presented in this paper. From the analysis of powder X-ray diffraction patterns, the nanocrystallite size was calculated by the most intense peak (3 1 1) using Scherrer formula. The crystallite size decreases with increase in aluminium concentartion. The lattice parameter 'a' also decreased with increase in aluminum concentration. The magnetic and electrical properties have been studied as a function of temperature. The Curie temperature was determined from AC magnetic susceptibility measurement. It is observed that Curie temperature decreases and DC electrical resistivity increases with increasing concentration of Al{sup 3+} ions. The observed variations in DC electrical resistivity have been explained by Verwey's hopping mechanism. The activation energy was found to increase with increasing Al{sup 3+} ions. The variations of dielectric constant for all the samples have been studied as a function of frequency in the range 500 Hz to 1 MHz at room temperature. The room temperature dielectric constant decreases with increase of trivalent Al{sup 3+} ions. The observed variation in dielectric constant has been explained on the basis of space charge polarization.

  1. A solution for the preparation of hexagonal M-type SrFe{sub 12}O{sub 19} ferrite using egg-white: Structural and magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Li, Tingting; Li, Yang; Wu, Ruonan; Zhou, Han; Fang, Xiaochen [Anhui Key Laboratory of Metal Materials and Processing, School of Materials Science and Engineering, Anhui University of Technology, Maanshan 243002 (China); Su, Shubing [School of Electronic and Information Engineering, Ningbo University of Technology, Ningbo 315016 (China); Xia, Ailin, E-mail: alxia@126.com [Anhui Key Laboratory of Metal Materials and Processing, School of Materials Science and Engineering, Anhui University of Technology, Maanshan 243002 (China); Jin, Chuangui; Liu, Xianguo [Anhui Key Laboratory of Metal Materials and Processing, School of Materials Science and Engineering, Anhui University of Technology, Maanshan 243002 (China)

    2015-11-01

    A new sol–gel route using egg-white as the binder of metal ions, is developed to prepare hexagonal M-type SrFe{sub 12}O{sub 19} ferrite in this study, and the effects of different atomic ratio of Sr and Fe (Sr/Fe), sintering temperature (T{sub s}) and usage of egg-white (M{sub ew}) on the phase formation, morphology and magnetic properties of specimens are studied. It is found that the single-phase SrFe{sub 12}O{sub 19} ferrite only can be obtained under a Sr/Fe of 1:8 and a T{sub s} between 1000 °C and 1300 °C. The magnetic properties of specimens are also obviously affected by the different Sr/Fe and T{sub s}, primarily due to the emergency of impurities. The M{sub ew} has an obvious impact on the crystallinity of specimens, which consequently affects their magnetic properties. In our study, the optimum conditions to prepare the single-phase SrFe{sub 12}O{sub 19} ferrite are Sr/Fe=1:8, M{sub ew}= 3 g and T{sub s} =1200 °C. - Highlights: • Single-phase SrM ferrite was obtained via a novel sol–gel method using egg-white. • Single-phase SrM ferrite was obtained under Sr/Fe=1:8 and T{sub s} between 1000 and 1300 °C. • The usage of egg-white affects the crystallinity and magnetic properties markedly.

  2. Magnetic and Electrical Characteristics of Bismuth Ferrite, Depending on the Impurities, Method of Preparation and Size of the Nanoparticles

    Directory of Open Access Journals (Sweden)

    V.M. Sarnatsky

    2016-10-01

    Full Text Available The prospect of application of the multiferroics in devices and spintronics devices is shown. A comparative analysis of magnetic and dielectric properties of nanostructures based on bismuth ferrite which were synthesized by various ways was made. The results of studies of the structure and properties of the nanostructured bismuth ferrite powder, synthesized by combustion of nitrate - organic precursors, are presented.

  3. Preparation and characterization of gelatin/cerium(Ⅲ) film

    Institute of Scientific and Technical Information of China (English)

    黄崇军; 黄雅钦; 田娜; 童元建; 殷瑞贤

    2010-01-01

    A novel gelatin film with antibacterial activity was prepared by electrostatic crosslinking using cerium (Ⅲ) nitrate hexahydrate as the crosslinking agent. The structure and properties of the films were investigated by Fourier transform infrared spectra, tensile tests, thermogravimetric analysis, static drop contact angle and disc diffusion method. The results showed that cross-linking could not only improve the thermal and mechanical properties and lower the hydrophilic property of the films, but also make...

  4. Preparation of Electrically Conductive Polystyrene/Carbon Nanofiber Nanocomposite Films

    Science.gov (United States)

    Sun, Luyi; O'Reilly, Jonathan Y.; Tien, Chi-Wei; Sue, Hung-Jue

    2008-01-01

    A simple and effective approach to prepare conductive polystyrene/carbon nanofiber (PS/CNF) nanocomposite films via a solution dispersion method is presented. Inexpensive CNF, which has a structure similar to multi-walled carbon nanotubes, is chosen as a nanofiller in this experiment to achieve conductivity in PS films. A good dispersion is…

  5. Preparation and evaluation of buccal bioadhesive films containing clotrimazole.

    Science.gov (United States)

    Singh, S; Jain, S; Muthu, M S; Tiwari, S; Tilak, R

    2008-01-01

    Buccal bioadhesive films, releasing topical drugs in the oral cavity at a slow and predetermined rate, provide distinct advantages over traditional dosage forms. The aim of present study was to prepare and evaluate buccal bioadhesive films of clotrimazole for oral candidiasis. The film was designed to release the drug at a concentration above the minimum inhibitory concentration for a prolonged period of time so as to reduce the frequency of administration of the available conventional dosage forms. The different proportions of sodium carboxymethylcellulose and carbopol 974P (CP 974P) were used for the preparation of films. Carbopol was used to incorporate the desired bioadhesiveness in the films. The films were prepared by solvent casting method and evaluated for bioadhesion, in vitro drug release and effectiveness against Candida albicans. In vitro drug release from the film was determined using a modified Franz diffusion cell while bioadhesiveness was evaluated with a modified two-arm balance using rabbit intestinal mucosa as a model tissue. Films containing 5% CP 974P of the total polymer were found to be the best with moderate swelling along with favorable bioadhesion force, residence time and in vitro drug release. The microbiological studies revealed that drug released from the film could inhibit the growth of C. albicans for 6 h. The drug release mechanism was found to follow non-Fickian diffusion.

  6. Nanoscale magnetization reversal caused by electric field-induced ion migration and redistribution in cobalt ferrite thin films.

    Science.gov (United States)

    Chen, Xinxin; Zhu, Xiaojian; Xiao, Wen; Liu, Gang; Feng, Yuan Ping; Ding, Jun; Li, Run-Wei

    2015-04-28

    Reversible nanoscale magnetization reversal controlled merely by electric fields is still challenging at the moment. In this report, first-principles calculation indicates that electric field-induced magnetization reversal can be achieved by the appearance of unidirectional magnetic anisotropy along the (110) direction in Fe-deficient cobalt ferrite (CoFe(2-x)O4, CFO), as a result of the migration and local redistribution of the Co(2+) ions adjacent to the B-site Fe vacancies. In good agreement with the theoretical model, we experimentally observed that in the CFO thin films the nanoscale magnetization can be reversibly and nonvolatilely reversed at room temperature via an electrical ion-manipulation approach, wherein the application of electric fields with appropriate polarity and amplitude can modulate the size of magnetic domains with different magnetizations up to 70%. With the low power consumption (subpicojoule) characteristics and the elimination of external magnetic field, the observed electric field-induced magnetization reversal can be used for the construction of energy-efficient spintronic devices, e.g., low-power electric-write and magnetic-read memories.

  7. Preparation and Characterization of Polymeric PVDF/PDDA Ultrathin Films

    Institute of Scientific and Technical Information of China (English)

    Yun Ye; Yadong Jiang; Yong Wang; Zhiming Wu; Guangzhong Xie

    2006-01-01

    A new method for the production of nanoscaled polymeric multilayer films of ferroelectric PVDF is presented. The ultrathin multilayer films of poly diallyldimethylammonium chloride (PDDA) and polyvinylidene fluoride (PVDF) have been prepared on fuzed quartz substrate by the layer-by-layer self-assembly (LbL-SA) method. The PDDA/PVDF multilayer films with the thickness of 30 nm to 150 nm have been characterized by quartz crystal microbalance (QCM) and infrared spectra (IR).The QCM reveals that the alternant ultrathin films of PVDF and PDDA are well order assembled. The electric property of the ultrathin PDDA/PVDF multilayer films at room temperature is investigated. Experimental results show that property of ultrathin films differed from that of the thick films.

  8. Preparation and characterization of polyimide/silica/silver composite films

    Institute of Scientific and Technical Information of China (English)

    Ning LUO; Zhanpeng WU; Nanxiang MOU; Lizhong JIANG; Dezhen WU

    2008-01-01

    Polyimide/silica/silver hybrid films were pre-pared by the sol-gel method combined with in situ single-stage self-metallization technique.The structure of polyi-mide films in the thermal curing process and the influence of silica content on the migration and aggregation of silver particles to the surface of hybrid films were investigated.The hybrid films were characterized by transmission elec-tron microscopy,dynamic mechanical thermal analysis,Fourier transform infrared spectroscopy,ultraviolet visible spectroscopy and mechanical measurements.The results indicated that there was no degradation of the polyimide matrix after the formation of silica and silver particles.Silica acted as the nucleus for the silver particles.With increasing silica content,more and more silver particles were kept in the hybrid films instead of being migrated onto the surface of the hybrid films and the reflections of hybrid films decreased gradually.

  9. Magnetic Properties of Nanometer-Scale NiZnCu Ferrite Thin Films Fabricated by Spray-Spin-Heating-Coating Method

    Institute of Scientific and Technical Information of China (English)

    Yulan JING; Huaiwu ZHANG; lijun JIA; Yu SHI; Yingli LIU

    2004-01-01

    A new nanometer-scale ferrite thin film with excellent high-frequency characteristics has been developed by the spray-spin-heating-coating method. The effects of the ion synthesis mechanism, chemical stoichiometry, fabrication method, and doping content on the magnetic properties and microstructure of the thin films have been analyzed.The films formed between 75℃ and 90℃ by spray-spin-heating-coating methods was discovered with fine grain size of about 21 nm, high saturation magnetization (4πMs) of about 6.5 kGs, coercivity of about 9.8 Oe, as well as initial permeability of about 14.0. These films can be widely used in radio-frequency integrated circuit devices.

  10. Novel transparent and flexible nanocomposite film prepared from chrysotile nanofibres

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Kun, E-mail: kliu@csu.edu.cn [School of Minerals Processing and Bioengineering, Central South University, Changsha 410083 (China); Zhu, Binnan; Feng, Qiming [School of Minerals Processing and Bioengineering, Central South University, Changsha 410083 (China); Duan, Tao [Joint Laboratory for Extreme Conditions Matter Properties, Southwest University of Science and Technology and Research Center of Laser Fusion, CAEP, Mianyang 621010 (China)

    2013-10-01

    In the present study, chrysotile nanofibres, obtained from physicochemical dispersion of natural chrysotile, were used to prepare nanofibre sheets by vacuum filtration. As-prepared sheets were then impregnated by UV-curable resin and cured by ultraviolet light to fabricate the flexible and transparent nanocomposite films. Observed from SEM, the transparent films showed a smooth surface and a typical sandwich structure in cross section, viz. nanofibre sheet filled with resin was sandwiched by two layers of resin. XRD patterns indicated the amorphous nature of cured resin and characteristic crystallographic structure of chrysotile in nanocomposite films. Though the nanofibre sheets were white in colour, and nanofibre contents in nanocomposites were as much as 43.4 wt%, the nanocomposite films displayed an excellent optical transparency with about 85% light transmittance in the visible light range. Tensile tests showed that the addition of nanofibres resulted in a great improvement in mechanical strength of the nanocomposite films; with the increase of nanofibre contents, the modulus and tensile strength of nanocomposite films increased gradually. - Graphical abstract: Photos show the experimental phenomenon. The white nanofibre sheets can be written or printed like paper, and it's very interested that the handwriting is clearly visible from the front and back of the transparent films prepared from nanofibre sheets by vacuum impregnation and UV curing. This phenomenon can be attributed to the increase of transparency of film, which results from the replacement of air interstices in nanofibre sheet by resin with higher refractive index. Visible light can pass easily through the transparent film without obvious loss, but can be apparently adsorbed and scattered by ink particles that adhered to nanofibres and embedded in resin. - Highlights: • A flexible and transparent film is prepared from chrysotile nanofibres. • The nanofibre sheet is sandwiched by two

  11. Microstructure parameters and optical properties of cadmium ferrite thin films of variable thickness

    Science.gov (United States)

    Shaaban, E. R.

    2014-06-01

    CdFe2O4 thin films of different thicknesses were deposited onto glass substrates by the thermal evaporation technique. Their structural characteristics were studied by X-ray diffraction (XRD). The microstructure parameters, crystallite size, and microstrain were calculated. It is observed that both the crystallite size increases and microstrain increase with increasing with the film thickness. The fundamental optical parameters like absorption coefficient and optical band gap are calculated in the strong absorption region of transmittance and reflectance spectrum. The refractive indices have been evaluated in terms of the envelope method, which has been suggested by Swanepoel in the transparent region. The refractive index can be extrapolated by the Cauchy dispersion relationship over the whole spectra range, which extended from 400 to 2500 nm. The refractive index, n, increases on increasing the film thickness up to 733 nm and the variation of n with higher thickness lies within the experimental errors.

  12. Barium titanate thick films prepared by screen printing technique

    Directory of Open Access Journals (Sweden)

    Mirjana M. Vijatović

    2010-06-01

    Full Text Available The barium titanate (BaTiO3 thick films were prepared by screen printing technique using powders obtained by soft chemical route, modified Pechini process. Three different barium titanate powders were prepared: i pure, ii doped with lanthanum and iii doped with antimony. Pastes for screen printing were prepared using previously obtained powders. The thick films were deposited onto Al2O3 substrates and fired at 850°C together with electrode material (silver/palladium in the moving belt furnace in the air atmosphere. Measurements of thickness and roughness of barium titanate thick films were performed. The electrical properties of thick films such as dielectric constant, dielectric losses, Curie temperature, hysteresis loop were reported. The influence of different factors on electrical properties values was analyzed.

  13. Electrical transport properties of CoZn ferrite-SiO{sub 2} composites prepared by co-precipitation technique

    Energy Technology Data Exchange (ETDEWEB)

    Islam, M.U. [Department of Physics, Bahauddin Zakariya University, Multan (Pakistan)], E-mail: muislampk@yahoo.com; Aen, Faiza [Department of Physics, Bahauddin Zakariya University, Multan (Pakistan); Niazi, Shahida B. [Department of Chemistry, Bahauddin Zakariya University, Multan (Pakistan); Azhar Khan, M.; Ishaque, M.; Abbas, T.; Rana, M.U. [Department of Physics, Bahauddin Zakariya University, Multan (Pakistan)

    2008-06-15

    CoZn ferrite-SiO{sub 2} composites having general formula (1 - x)Co{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} + xSiO{sub 2} with x = 0.0-0.8 were prepared by co-precipitation technique. The X-ray diffraction analysis of the composites reveals that they are bi-phase. Room temperature resistivity increases from 10{sup 5} to 10{sup 9} ({omega} cm) from x = 0.0-0.8. This drastic increase in resistivity may be attributed to the presence of pores and the segregation of Si at grain boundaries. The Arrhenius plots of these samples show that resistivity decreases as the temperature increases indicating their semi conducting behavior. Arrhenius plots show a change of slope at particular temperature (except for x = 0.8) that may be attributed to their Curie temperature. It is observed that the activation energies are small in Para-region as compared to Ferri-region and is an indication of the hopping conduction mechanism. The variation of thermopower with temperature reveals that these samples are degenerate type semiconductors. The values of activation energies calculated from log {mu}{sub d} vs. 1000/T are slightly lower than the values of activation energies obtained from Arrhenius plots. This suggests that the conduction phenomenon is due to polaron hopping.

  14. Temperature dependent structural and magnetic properties of Cerium substituted Co–Cr ferrite prepared by auto-combustion method

    Energy Technology Data Exchange (ETDEWEB)

    Mustafa, Ghulam, E-mail: ghulammustafabzu@gmail.com [Department of Physics, Bahauddin Zakariya University, Multan 60800 (Pakistan); Islam, M.U. [Department of Physics, Bahauddin Zakariya University, Multan 60800 (Pakistan); Zhang, Wenli [State Key Laboratory of Electronic Thin Films and Integrated Devices, UESTC, Chengdu 610054 (China); Jamil, Yasir [Department of Physics, University of Agriculture, Faisalabad 38040 (Pakistan); Asif Iqbal, M.; Hussain, Mudassar [Department of Physics, Bahauddin Zakariya University, Multan 60800 (Pakistan); Ahmad, Mukhtar, E-mail: ahmadmr25@yahoo.com [Department of Physics, COMSATS Institute of Information Technology, Islamabad 44000 (Pakistan)

    2015-03-15

    The effects of heat treatment on a nano-crystalline spinel ferrite with chemical formula CoCr{sub 0.04}Ce{sub x}F{sub e1.96−x}O{sub 4} (x=0.06) were investigated in the present work. The sample was prepared by the auto-combustion method and then heat treated at 700–1200 °C for 8 h. The sample heat treated at these temperatures was investigated using thermo-gravimetric analyses and differential scanning calorimetry, X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy and vibrating sample magnetometery. The XRD patterns and IR spectra confirmed that the synthesized materials were of single phase at and above 900 °C. The average particle size was found to be in the range of 30.8–63.8 nm estimated by the Scherer formula. IR studies confirm two main absorption bands in the frequency range of 400–800 cm{sup −1} arising due to the tetrahedral (A-site) and octahedral (B-site) stretching vibrations. The average grain size increased with the increase of temperature while distribution of particles became homogeneous as observed by scanning electron microscope. The saturation magnetization was increased gradually from 7.4 to 59.6 emu/g with the increase of temperature. The coercivity lies in the range of 248–811 Oe as a function of temperature. The obtained results suggest that the investigated materials may be potential candidates for high density recording media applications. - Highlights: • Effects of temperature on structural and magnetic parameters of spinel ferrite are studied. • The XRD patterns confirms that the materials are of single phase at and above 900 °C. • The M{sub s} was increased gradually from 7.4–59.6 emu/g with the increase of temperature. • The values of coercivity lie in the range of 248–811 Oe as a function of temperature. • The results show that materials may have a potential for high density recording media.

  15. ZnO thin films prepared by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Tsoutsouva, M.G. [Laboratory of Physical Metallurgy, National Technical University of Athens, Zografos, 15780 Athens (Greece); Panagopoulos, C.N., E-mail: chpanag@metal.ntua.gr [Laboratory of Physical Metallurgy, National Technical University of Athens, Zografos, 15780 Athens (Greece); Papadimitriou, D. [National Technical University of Athens, Department of Physics, GR-15780 Athens (Greece); Fasaki, I.; Kompitsas, M. [Theor. and Phys./Chem. Institute, National Hellenic Research Foundation, 48 Vas. Konstantinou Ave., 11635 Athens (Greece)

    2011-04-15

    Zinc oxide (ZnO) thin films were deposited on soda lime glass substrates by pulsed laser deposition (PLD) in an oxygen-reactive atmosphere. The structural, optical, and electrical properties of the as-prepared thin films were studied in dependence of substrate temperature and oxygen pressure. High quality polycrystalline ZnO films with hexagonal wurtzite structure were deposited at substrate temperatures of 100 and 300 deg. C. The RMS roughness of the deposited oxide films was found to be in the range 2-9 nm and was only slightly dependent on substrate temperature and oxygen pressure. Electrical measurements indicated a decrease of film resistivity with the increase of substrate temperature and the decrease of oxygen pressure. The ZnO films exhibited high transmittance of 90% and their energy band gap and thickness were in the range 3.26-3.30 eV and 256-627 nm, respectively.

  16. Structural and Magnetic Characterizations of Nano Sized Grain Zinc Ferrite/Hydroxyapatite Ceramic Prepared by Solid State Reaction Route.

    Science.gov (United States)

    Pankaew, Piyapong; Klumdoung, Pattarinee

    2015-11-01

    A promising composite of bioactive hydroxyapatite (HAp) and zinc ferrite (ZnFe2O4) has potentials for future bone reinforcing formation. In present study, HAp and ZnFe2O4 composite ceramic was prepared by solid state reaction route for easier control of structural and magnetic characteristics and with low cost. HAp powder was synthesized by precipitation method from chicken eggshell. Mixed powders with varying ZnFe2O4/HAp weight ratios from 2-10 wt% were milled together and uniaxially pressed and then sintered at 1200 degrees C for 3 hours. The XRD results showing no other phases of composite ceramics with only HAp and ZnFe2O4 phases were identified, indicating high stability of HAp property. Phase fractions of ZnFe2O4 were found to increase from 10.8 to 18.73 wt% with increasing content of ZnFe2O4. FT-IR results were only revealed vibration bands of standard HAp phase. SEM results revealed primary grains sizes of the prepared ceramics in nano scale. The BET surface area and pore volume increased with increasing content of ZnFe2O4 in composite ceramics. The VSM results of composites with increasing ZnFe2O4 content had been shown with increasing magnetization from 0.05 to 1.85 emu/g while their coercivities were decreased from 44 to 24 Oe. Higher magnetization as well as higher super paramagnetic behavior could be achieved with increasing the studied ZnFe2O4 weight ratios in ZnFe2O4/HAp composite ceramics, which can be tailored for specific applications.

  17. Investigation of Hexagonal Ferrite Film Growth Techniques for Millimeter-Wave Systems Applications.

    Science.gov (United States)

    1987-03-15

    34.P thnto :avity had ’(. w a value i unkncwn-, h agair. no3 %1’ IP batch tl) gave no results either. Thus all data reported below at Ka band were...ons ctiori th Il(,a- film grossk th is, currentlr more ad\\ anced. the poten- phase *\\I tead\\ I,: these floss s are in a at, tial of the (o~ia .0

  18. Screen-printed (La,Sr)CrO3 coatings on ferritic stainless steel interconnects for solid oxide fuel cells using nanopowders prepared by means of ultrasonic spray pyrolysis

    Science.gov (United States)

    Brylewski, Tomasz; Dabek, Jaroslaw; Przybylski, Kazimierz; Morgiel, Jerzy; Rekas, Mieczyslaw

    2012-06-01

    In order to protect the cathode from chromium poisoning and improve electrical resistance, a perovskite (La,Sr)CrO3 coating was deposited on the surface of a DIN 50049 ferritic stainless steel by means of the screen-printing method, using a paste composed of an ultra-fine powder prepared via ultrasonic spray pyrolysis. Investigations of the oxidation process of the coated steel in air and the Ar-H2-H2O gas mixture at 1073 K for times up to 820 h showed high compactness of the protective film, good adhesion to the metal substrate, as well as area specific resistance (ASR) at a level acceptable for metallic SOFC interconnect materials. The microstructure, nanostructure, phase composition of the thick film, and in particular the film/substrate interface, were examined via chemical analyses by means of SEM-EDS and TEM-SAD. It was shown that the (La,Sr)CrO3 coating interacts with the steel during long-term thermal oxidation in the afore-mentioned conditions and intermediate, chromia-rich and/or spinel multilayer interfacial zones are formed. Cr-vaporization tests showed that the (La,Sr)CrO3 coating may play the role of barriers that decrease the volatilization rate of chromia species.

  19. Preparation of Rodlike Barium Ferrite Particles by Inverse Microemulsion Method%棒状钡铁氧体的反相微乳法制备

    Institute of Scientific and Technical Information of China (English)

    杨鹏飞; 王明刚; 孟凡君; 张俊华; 孙爱娟; 鲁成学

    2005-01-01

    A rodlike barium ferrite precursor with an average size of 0.72-19.6μm and aspect ratio of 2.6~8.3 has been successfully prepared in an inverse microemulsion consisting of isooctane, cetanyl trimethyl ammonium bromide (CTAB), n-C4H9OH and water with ammonia and ammonium oxalate as precipitants. On sintering at 780 (C, the rodlike precursor particles could be transformed into rodlike particles of barium ferrite(BaFe12O19) with the average size and aspect ratio of 0.69-18.2μm and 2.3~5.8, respectively. The effect of volume ratio of aqueous phase to oleic phase, the starting concentrations of metal ions and the starting concentration ratios of metal ions to precipitants were investigated.

  20. Effects of Heat-treatment on Microstructure and Magnetic Properties of Ba Ferrite Ultrafine Powders Prepared by Sol-gel

    Institute of Scientific and Technical Information of China (English)

    KONG Xiao-dong; Zhu Mei-wu; ZHENG Jia-sheng

    2004-01-01

    Barium (Bag) ferrite ultra fine powders were synthesized by using sol-gel in which polyethylene glycol200(PEG200) was used as gelling agent. The transition of Ba ferrite was studied by thermal gravimetric and differential thermal analysis (TG-DTA) technology. The micro structural changes were analyzed using X-ray diffraction (XRD) and atomic force microscopy (AFM) for the specimens annealed at different temperatures. The transition temperatures were 414.55 ℃ and 755.78 ℃ separately corresponding to BaFe2O4 and BaFe12O19. There were three types of microstructures for Ba ferrite ultrafine powder specimen annealed at 800℃. For the specimens annealed at different temperatures, there were different kinds of Ba ferrites. The ferrite powder consists of BaFe12O19 and BaFe2O4 for the specimen annealed at 800℃,and only BaFe12O19 can be found in the specimen annealed at 1000℃. The magnetic properties, σ s and H c of BaFe12O19ultrafine powders are different from that of BaFe12O19 bulk material.Key Words: Barium ferrite; ultrafine powder; microstructure; AFM; magnetic property

  1. Actuation Behavior of Polylactic Acid Fiber Films Prepared by Electrospinning.

    Science.gov (United States)

    Nobeshima, Taiki; Ishii, Yuya; Sakai, Heisuke; Uemura, Sei; Yoshida, Manabu

    2016-04-01

    A poly-DL-lactide (PLA) fiber film was prepared using the electrospinning method. This film consisted of randomly oriented PLA nanofibers. Consequently, it had sponge-like structure and was quite soft compared to PLA films prepared by spin coating. The average diameter of the fibers and the density of the film were 730 nm and 20%, respectively. By applying a voltage, the PLA film was subjected to electric-field-induced strain: expansion and compression in the thickness direction. When a voltage of -200 V was applied to the film, its thickness shrank from 13.5 µm to 10.0 µm (a 26% reduction). Electric-field-induced strain can occur via two different mechanisms: The first is electrostrictive behavior. That. is, in a highly electric field region, a change of film thickness occurs (compression only) from the electrostatic force between electrodes. The second mechanism is piezoelectric-like behavior that occurs in racemic PLA, wherein a PLA nanofiber is expanded and compressed by applying positive and negative voltage. Such piezoelectric-like behavior was not observed in spin-coated PLA films.

  2. Electrochemical biosensors utilizing the electron transfer of hemoglobin immobilized on cobalt-substituted ferrite nanoparticles-chitosan film

    Energy Technology Data Exchange (ETDEWEB)

    Yang Weiying; Zhou Xia; Zheng Na [College of Chemistry and Chemical Engineering, Graduate University, Chinese Academy of Sciences, Yuquan Road 19A, Beijing 100049 (China); Li Xiangjun, E-mail: lixiangj@gucas.ac.cn [College of Chemistry and Chemical Engineering, Graduate University, Chinese Academy of Sciences, Yuquan Road 19A, Beijing 100049 (China); Yuan Zhuobin [College of Chemistry and Chemical Engineering, Graduate University, Chinese Academy of Sciences, Yuquan Road 19A, Beijing 100049 (China)

    2011-07-30

    Cobalt ferrite nanoparticles (Co{sub x}Fe{sub 3-x}O{sub 4}) and chitosan (CS) film were used to immobilize/adsorb hemoglobin (Hb) to create a protein electrode to study the direct electron transfer between the redox centers of the proteins and the electrode. X-ray diffraction (XRD) and transmission electron microscopy (TEM) revealed that the Co{sub x}Fe{sub 3-x}O{sub 4} particles were nanoscale in size and formed an ordered layered structure. The native structure of the immobilized Hb was preserved as indicated by Fourier-transform infrared (FTIR) and UV-visible (UV-vis) spectroscopy. The Hb-Co{sub x}Fe{sub 3-x}O{sub 4}-CS modified electrode showed a pair of well-defined and quasi-reversible cyclic voltammetric peaks at -0.373 V (vs. SCE) and exhibited appreciable electrocatalytic activity for the reduction of H{sub 2}O{sub 2}. The catalysis currents increased linearly with H{sub 2}O{sub 2} concentration in a wide range of 5.0 x 10{sup -8} to 1.0 x 10{sup -3} mol L{sup -1} with a detection limit of 1.0 x 10{sup -8} mol L{sup -1} (S/N = 3) and had long-term stability. Finally, the proposed method was applied to investigate the coexistence of hydrogen peroxide with the interfering substances. Experimental results showed that the ascorbic acid, glucose, L-cysteine, uric acid, and dopamine at corresponding concentrations did not influence the detection of H{sub 2}O{sub 2}.

  3. Structure of silicon oxide films prepared by vacuum deposition

    Science.gov (United States)

    Saito, Yoshio; Kaito, Chihiro; Nishio, Kenzo; Naiki, Toshio

    1985-05-01

    The structure of thin silicon oxide films 5 nm in thickness, which were prepared by electron beam evaporation of SiO 2 glass onto a NaCl substrate, has been examined by high resolution electron microscopy and diffraction. Although the films which were prepared with substrate temperatures ranging from room up to 400°C gave rise to amorphous haloes, lattice fringes in areas 1-2 nm in extent were, however, seen in the micrographs. It is shown that the film is composed of α-quartz micro-crystallites. Crystals of α-cristobalite with sizes of several tens of nanometers appeared at a substrate temperature of 500°C. At a substrate temperature of 600°C, β-cristobalite crystals with sizes of several tens of nanometers appeared. The structural changes due to the substrate temperature were attributed to incorporation of sodium atoms from the substrate into the SiO 2 film.

  4. Preparation and Characterization of Chitosan-Agarose Composite Films.

    Science.gov (United States)

    Hu, Zhang; Hong, Pengzhi; Liao, Mingneng; Kong, Songzhi; Huang, Na; Ou, Chunyan; Li, Sidong

    2016-09-30

    Nowadays, there is a growing interest to develop biodegradable functional composite materials for food packaging and biomedicine applications from renewable sources. Some composite films were prepared by the casting method using chitosan (CS) and agarose (AG) in different mass ratios. The composite films were analyzed for physical-chemical-mechanical properties including tensile strength (TS), elongation-at-break (EB), water vapor transmission rate (WVTR), swelling ratio, Fourier-transform infrared spectroscopy, and morphology observations. The antibacterial properties of the composite films were also evaluated. The obtained results reveal that an addition of AG in varied proportions to a CS solution leads to an enhancement of the composite film's tensile strength, elongation-at-break, and water vapor transmission rate. The composite film with an agarose mass concentration of 60% was of the highest water uptake capacity. These improvements can be explained by the chemical structures of the new composite films, which contain hydrogen bonding interactions between the chitosan and agarose as shown by Fourier-transform infrared spectroscopy (FTIR) analysis and the micro-pore structures as observed with optical microscopes and scanning electron microscopy (SEM). The antibacterial results demonstrated that the films with agarose mass concentrations ranging from 0% to 60% possessed antibacterial properties. These results indicate that these composite films, especially the composite film with an agarose mass concentration of 60%, exhibit excellent potential to be used in food packaging and biomedical materials.

  5. Preparation and gaseous photocatalytic activity of smooth potassium dititanate film

    Institute of Scientific and Technical Information of China (English)

    Qinghua QIAN; Yuyan HU; Gaofei WEN; Xin FENG; Xiaohua LU

    2008-01-01

    A new smooth potassium dititanate film was prepared by sol-gel method and characterized by thermo-gravimetry (TG) and differential scanning calorimetry (DSC),X-ray diffraction (XRD),atomic force microscopy (AFM),UV-Visible diffuse reflectance and Raman spectro-scopy.The gaseous photocatalytic activity of smooth K2Ti2O5 films was studied using contact angle analysis from the photocatalytic decomposition of octadecyltri-chlo-rosilane (OTS) based self-assembled monolayers (SAMs) formed on K2Ti2O5 films.The photocurrent res-ponse of the film was determined by an electrochemical method.It was shown that the films were smooth,compact,and transparent when formed on glass.Compared with TiO2 film,the K2Ti2O5 film showed wide absorption in the ultraviolet and visible region.It was found that the monolayers on K2Ti2O5 decomposed much faster than those on TiO2 under UV irradiation of 254 nm in air.The film also exhibited a stronger photoresponse and a more stable anodic photocurrent.The K2Ti2O5 film effi-ciently decomposes the alkylsiloxane monolayers under UV irradiation in air and it was found to be a good photo-catalyst for gaseous organic pollutant treatment.

  6. Oxygen incorporation in porous thin films of strontium doped lanthanum ferrite

    DEFF Research Database (Denmark)

    Søgaard, Martin; Bieberle-Hütter, A.; Hendriksen, Peter Vang

    2011-01-01

    Electrical conductivity relaxation measurements were carried out on thin films of (La0.6Sr0.4)0.99 FeO3 − δ deposited on MgO (100) substrates by pulsed laser deposition in order to determine the surface exchange coefficient, k Ex, of the oxygen incorporation process in the temperature range 550...... structure and significant texturing. At a constant temperature, k Ex was found to be a function only of the final pO2pO2 of the pO2pO2-changes the sample was subjected to during conductivity relaxation experiments, confirming that the magnitude of the exchange coefficient was not influenced by changes...... in ionic defect concentrations. The k Ex-values determined for these thin films were significantly lower than for bulk samples. A value of 3.6 × 10 − 6 cm s − 1 was obtained at 702°C and a final pO2pO2 of 0.048 atm, approximately a factor of six lower than that obtained for bulk samples. An activation...

  7. Platinum-Iridium Alloy Films Prepared by MOCVD

    Institute of Scientific and Technical Information of China (English)

    WEI Yan; CHEN Li; CAI Hongzhong; ZHENG Xu; YANG Xiya; HU Changyi

    2012-01-01

    Platinum-Iridium alloy films were prepared by MOCVD on Mo substrate using metal-acetylacetonate precursors.Effects of deposition conditions on composition,microstructure and mechanical properties were determined.In these experimental conditions,the purities of films are high and more than 99.0%.The films are homogeneous and monophase solid solution of Pt and Ir.Weight percentage of platinum are much higher than iridium in the alloy.Lattice constant of the alloy changes with the platinum composition.Iridium composition showing an up-down-up trend at the precursor temperature of 190~230℃ and the deposition temperature at 400~550℃.The hardness of Pt-Ir alloys prepared by MOCVD is three times more than the alloys prepared by casting.

  8. Electrochemical preparation of polypyrrole conducting films

    Directory of Open Access Journals (Sweden)

    Mária Filkusová*

    2010-12-01

    Full Text Available Cyclic voltammetry has been used to investigate the electrochemical polymerization of pyrrole on the surface of a paraffin impregnated graphite electrode (PIGE. Effect of pH and concentration of the electrolyte solution on the electrochemical deposition of polypyrrole (PPy was studied. The structure of the deposited layers was studied using scanning electron microscope (SEM. Well–adhering black PPy films were obtained.

  9. Preparation, properties and applications of wheat gluten edible films

    Directory of Open Access Journals (Sweden)

    P. TANADA-PALMU

    2008-12-01

    Full Text Available Edible films from wheat gluten were prepared with various amounts of glycerol as a plasticizer. Water vapor permeability, oxygen permeability, tensile strength and percentage elongation at break at different water activities ( aw were measured. Films with low amounts of glycerol had lower water vapor and oxygen permeabilities, higher tensile strength and lower elongation at break. Wheat gluten coatings reduced weight loss during two weeks of storage for cherry tomatoes and sharon fruits compared to uncoated controls. A bilayer film of wheat gluten and beeswax significantly lowered weight loss from coated cheese cubes compared to single layer coating of wheat gluten.;

  10. Preparation and characterization of Zn Se thin films

    CERN Document Server

    Ganchev, M; Stratieva, N; Gremenok, V; Zaretskaya, E; Goncharova, O

    2003-01-01

    Chemical bath deposition technique for preparation of ZnSe thin films is presented. The influence of bath temperature and duration of deposition on film growth and quality has been studied. The effect of post-deposition annealing in different ambient is also discussed. It has been determined that heat treatment removes the oxygen-containing phase from the as-deposited films and improves crystallinity. The optical and electric properties of the deposits show their potential for an alternative buffer layer in chalcopyrite-based solar cells.

  11. Magnetic, ferroelectric and leakage current properties of gadolinium doped bismuth ferrite thin films by sol–gel method

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Hone-Zern, E-mail: hzc@hust.edu.tw [Department of Electronic Engineering, Hsiuping University of Science and Technology, Taichung, Taiwan (China); Kao, Ming-Cheng, E-mail: kmc@hust.edu.tw [Department of Electronic Engineering, Hsiuping University of Science and Technology, Taichung, Taiwan (China); Young, San-Lin [Department of Electronic Engineering, Hsiuping University of Science and Technology, Taichung, Taiwan (China); Hwang, Jun-Dar [Department of Electrophysics, National Chiayi University, Chiayi, Taiwan (China); Chiang, Jung-Lung [Department of Mobile Technology, Toko University, Chiayi, Taiwan (China); Chen, Po-Yen [Department of Electronic Engineering, Hsiuping University of Science and Technology, Taichung, Taiwan (China)

    2015-05-01

    Bi{sub 0.9}Gd{sub 0.1}FeO{sub 3} (BGFO) thin films were fabricated on Pt(111)/Ti/SiO{sub 2}/Si(100) substrates by using the sol–gel technology. The effects of annealing temperature (400–700 °C) on microstructure and multiferroic properties of thin films were investigated. The X-ray diffraction analysis showed that the BGFO thin films had an orthorhombic structure. The thin films showed ferroelectric and ferromagnetic properties with remanent polarization (2P{sub r}) of 10 μC/cm{sup 2}, remnant magnetization (2M{sub r}) of 2.4 emu/g and saturation magnetization (M{sub s}) of 5.3 emu/g. A small leakage current density (J) was 4.64×10{sup −8} A/cm{sup 2} under applied field 100 kV/cm. It was found that more than one conduction mechanism is involved in the electric field range used in these experiments. The leakage current mechanisms were controlled by Poole–Frenkel emission in the low electric field region and by Schottky emission from the Pt electrode in the high field region. - Highlights: • Bi{sub 3.96}Pr{sub 0.04}Ti{sub 2.95}Nb{sub 0.05}O{sub 12} thin films were prepared by sol–gel technology. • Thin films showed 2P{sub r} of 10 μC/cm{sup 2}, 2M{sub r} of 2.4 emu/g and M{sub s} of 5.3 emu/g. • Leakage current mechanisms were controlled by Poole–Frenkel and Schottky emission.

  12. Co-Zn ferrite nanoparticles for ferrofluid preparation: Study on magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Arulmurugan, R. [Department of Physics, Pondicherry Engineering College, Pondicherry 605 014 (India)]. E-mail: arulphysics@rediffmail.com; Vaidyanathan, G. [Department of Physics, Pondicherry Engineering College, Pondicherry 605 014 (India); Sendhilnathan, S. [Department of Physics, Sri Manakula Vinayagar Engineering College, Pondicherry 605 107 (India); Jeyadevan, B. [Graduate School of Environmental Studies, Tohoku University, Sendai 980-8579 (Japan)

    2005-06-15

    Co-Zn substituted nanoferrites having stoichiometric composition Co{sub 1-} {sub x} Zn {sub x} Fe{sub 2}O{sub 4} with x ranging from 0.1 to 0.5 were prepared by chemical coprecipitation method. The precipitated particles were used for the preparation of ferrofluid. Ferrofluids having Co{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} particles could be used for the energy conversion application utilizing the magnetically induced convection for thermal dissipation. The final estimated cation contents, agreed with the initial degree of substitution. The powder samples were characterized by XRD, TEM, VSM and Mossbauer studies. The precipitated particles showed single-phase fcc spinel structure for all compositions of zinc. The magnetic parameters such as M {sub s}, H {sub c,} M {sub r}, T {sub c} and particle size were found to decrease with the increase in zinc substitution. In the case of particles with higher zinc concentration, both ferrimagnetic nanoparticles and particles exhibiting superparamagnetic behavior were present. The fine particles were suitably dispersed in heptane using oleic acid as the surfactant. Volatile nature of the carrier chosen helped in altering the number concentration of the magnetic particles in a ferrofluid.

  13. Studies on the preparation of active oxygen-deficient copper ferrite and its application for hydrogen production through thermal chemical water splitting

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Hydrogen generation through thermal chemical water splitting technology has recently received in- creasingly international interest in the nuclear hydrogen production field. Besides the main known sulfur-iodine (S-I) cycle developed by the General Atomics Company and the UT3 cycle (iron, calcium, and bromine) developed at the University of Tokyo, the thermal cycle based on metal oxide two-step water splitting methods is also receiving research and development attention worldwide. In this work, copper ferrite was prepared by the co-precipitation method and oxygen-deficient copper ferrite was synthesized through first and second calcination steps for the application of hydrogen production by a two-step water splitting process. The crystal structure, properties, chemical composition and δ were investigated in detail by utilizing X-ray diffraction (XRD), thermogravimetry (TG) and differential thermal analysis (DTA), atomic absorption spectrometer (AAS), ultraviolet spectrophotometry (UV), gas chro- matography (GC), and so on. The experimental two-step thermal chemical cycle reactor for hydrogen generation was designed and developed in this lab. The hydrogen generation process of water splitting through CuFe2O4-δ and the cycle performance of copper ferrite regeneration were firstly studied and discussed.

  14. Studies on the preparation of active oxygen-deficient copper ferrite and its application for hydrogen production through thermal chemical water splitting

    Institute of Scientific and Technical Information of China (English)

    YU Bo; ZHANG Ping; ZHANG Lei; CHEN Jing; XU JingMing

    2008-01-01

    Hydrogen generation through thermal chemical water splitting technology has recently received in-creasingly international interest in the nuclear hydrogen production field. Besides the main known sulfur-iodine (S-I) cycle developed by the General Atomics Company and the UT3 cycle (iron, calcium, and bromine) developed at the University of Tokyo, the thermal cycle based on metal oxide two-step water splitting methods is also receiving research and development attention worldwide. In this work, copper ferrite was prepared by the co-precipitation method and oxygen-deficient copper ferrite was synthesized through first and second calcination steps for the application of hydrogen production by a two-step water splitting process. The crystal structure, properties, chemical composition and δwere investigated in detail by utilizing X-ray diffraction (XRD), thermogravimetry (TG) and differential thermal analysis (DTA), atomic absorption spectrometer (AAS), ultraviolet spectrophotometry (UV), gas chro-matography (GC), and so on. The experimental two-step thermal chemical cycle reactor for hydrogen generation was designed and developed in this lab. The hydrogen generation process of water splitting through CuFe2O4-δ and the cycle performance of copper ferrite regeneration were firstly studied and discussed.

  15. Microwave applications of soft ferrites

    CERN Document Server

    Pardavi-Horvath, M P

    2000-01-01

    Signal processing requires broadband, low-loss, low-cost microwave devices (circulators, isolators, phase shifters, absorbers). Soft ferrites (garnets, spinels, hexaferrites), applied in planar microwave devices, are reviewed from the point of view of device requirements. Magnetic properties, specific to operation in high-frequency electromagnetic fields, are discussed. Recent developments in thick film ferrite technology and device design are reviewed. Magnetic losses related to planar shape and inhomogeneous internal fields are analyzed.

  16. Preparation and Characterization of Chitosan—Agarose Composite Films

    Directory of Open Access Journals (Sweden)

    Zhang Hu

    2016-09-01

    Full Text Available Nowadays, there is a growing interest to develop biodegradable functional composite materials for food packaging and biomedicine applications from renewable sources. Some composite films were prepared by the casting method using chitosan (CS and agarose (AG in different mass ratios. The composite films were analyzed for physical-chemical-mechanical properties including tensile strength (TS, elongation-at-break (EB, water vapor transmission rate (WVTR, swelling ratio, Fourier-transform infrared spectroscopy, and morphology observations. The antibacterial properties of the composite films were also evaluated. The obtained results reveal that an addition of AG in varied proportions to a CS solution leads to an enhancement of the composite film’s tensile strength, elongation-at-break, and water vapor transmission rate. The composite film with an agarose mass concentration of 60% was of the highest water uptake capacity. These improvements can be explained by the chemical structures of the new composite films, which contain hydrogen bonding interactions between the chitosan and agarose as shown by Fourier-transform infrared spectroscopy (FTIR analysis and the micro-pore structures as observed with optical microscopes and scanning electron microscopy (SEM. The antibacterial results demonstrated that the films with agarose mass concentrations ranging from 0% to 60% possessed antibacterial properties. These results indicate that these composite films, especially the composite film with an agarose mass concentration of 60%, exhibit excellent potential to be used in food packaging and biomedical materials.

  17. /dopamine films prepared by sol-gel method

    Science.gov (United States)

    Valverde-Aguilar, G.; Prado-Prone, G.; Vergara-Aragón, P.; Garcia-Macedo, J.; Santiago, Patricia; Rendón, Luis

    2014-09-01

    Dopamine was encapsulated into nanoporous amorphous TiO2 matrix by sol-gel method under atmospheric conditions. A second sample was obtained by the addition of the crown-ether 15C5 in this previous sample. Thin films were spin-coated on glass wafers. No heat treatment was employed in both films. All films were characterized using infrared spectroscopy, high resolution transmission electronic microscopy, X-ray diffraction, optical absorption and scanning electronic microscopy. Despite the films prepared with 15C5 were no calcined, a partial crystallization was identified. Anatase and rutile nanoparticles with sizes of 4-5 nm were obtained. Photoconductivity technique was used to determine the charge transport mechanism on these films. Experimental data were fitted with straight lines at darkness and under illumination wavelengths at 320, 400, and 515 nm. It indicates an ohmic behavior. Photovoltaic and photoconductivity parameters were determined from the current density vs. the applied-electrical-field results. Amorphous film has bigger photovoltaic and photoconductive parameters than the partially crystalline film. Results observed in the present investigation prove that the nanoporous TiO2 matrix can protect the dopamine inhibiting its chemical instability. This fact modifies the optical, physical and electrical properties of the film, and is intensified when 15C5 is added.

  18. Preparation and magnetic properties of Co-P thin films

    Institute of Scientific and Technical Information of China (English)

    Haicheng Wang; Zhongmei Du; Lijin Wang; Guanghua Yu; Fengwu Zhu

    2008-01-01

    Magnetic Co-P thin films were prepared by eleetroless deposition. The experiment results show that the film thickness has a significant influence on the coercivity. While the film thickness varied from 300 nm to 5 μm, the coercivity dropped sharply from 45.36 to 22.28 kA/m. As the film thickness increased further, the coercivity varied slowly. When the thickness of the film was 300 nm, the deposited film could realize the coercivity as high as 45.36 kA/m, and the remanent magnetization as high as 800 kA/m .The Co-P films were deposited on the surface of magnetic drums of encoders, whose diameter was 40 mm, and then 512 magnetic poles were recorded, meaning that the magnetizing pitch was 0.245 mm. The testing results indicate that the output signals are perfect, the output waveforms are steady and the pulses account is integral. Compared with the γ-Fe2O3 coating, the Co-P thin film is suitable to be the magnetic recording media for the high resolution magnetic rotary encoder.

  19. Sol-gel preparation of silica and titania thin films

    Science.gov (United States)

    Thoř, Tomáš; Václavík, Jan

    2016-11-01

    Thin films of silicon dioxide (SiO2) and titanium dioxide (TiO2) for application in precision optics prepared via the solgel route are being investigated in this paper. The sol-gel process presents a low cost approach, which is capable of tailoring thin films of various materials in optical grade quality. Both SiO2 and TiO2 are materials well known for their application in the field of anti-reflective and also highly reflective optical coatings. For precision optics purposes, thickness control and high quality of such coatings are of utmost importance. In this work, thin films were deposited on microscope glass slides substrates using the dip-coating technique from a solution based on alkoxide precursors of tetraethyl orthosilicate (TEOS) and titanium isopropoxide (TIP) for SiO2 and TiO2, respectively. As-deposited films were studied using spectroscopic ellipsometry to determine their thickness and refractive index. Using a semi-empirical equation, a relationship between the coating speed and the heat-treated film thickness was described for both SiO2 and TiO2 thin films. This allows us to control the final heat-treated thin film thickness by simply adjusting the coating speed. Furthermore, films' surface was studied using the white-light interferometry. As-prepared films exhibited low surface roughness with the area roughness parameter Sq being on average of 0.799 nm and 0.33 nm for SiO2 and TiO2, respectively.

  20. Preparation of biaxially oriented TlCu-1234 thin films

    CERN Document Server

    Khan, N A; Tateai, F; Kojima, T; Ishida, K; Terada, N; Ihara, H

    1999-01-01

    The single phase of TlCu-1234 superconductor thin films is prepared for the first time by the amorphous phase epitaxy (APE) method, which is thallium treatment of sputtered amorphous phase at 900 degrees C for 1 h. The amorphous $9 phase is prepared by sputtering from the stoichiometric target composition CuBa/sub 2/Ca/sub 3/Cu/sub 4/O/sub 12-y/. The films on the SrTiO/sub 3/ substrate are aligned biaxially after the thallium treatment. Highly reproducible $9 TlCu-1234 films are prepared by this method. The XRD reflected a predominant single phase with the c-axis lattice constant of 18.74 AA. This lattice constant value is in between that of Cu-1234 (17.99 AA) and Tl-1234 (19.11 AA) . The $9 pole figure measurements of (103) reflection of the films showed a-axis-oriented crystals with Delta phi =0.8 degrees . The composition of the films after energy dispersive X-ray (EDX) measurements is Tl/sub 0.8/Cu/sub 0.2/Ba/sub $9 2/Ca/sub 3/Cu/sub 4/O /sub 12-y/. From the resistivity measurements, the T/sub c/ is 113 K...

  1. Preparation and Characterization of PZT films Fabricated on Si Substrate

    Institute of Scientific and Technical Information of China (English)

    YANG Ying

    2006-01-01

    Lead zirconium titanate (PZT) films (Zr/Ti=45:55)with a high dielectric constant are prepared successfully on the low-resistance Si substrate in sol-gel dip-coating process with PT film used as the buffer layer.The dielectric and ferroelectric properties of the films as well as the relationship between crystallization and preparing condition are studied.It is shown that the PZT ferroelectric thin films with a (110) preferred orientation and a well-crystallized perovskite structure could be obtained after annealing at 800℃ for 15 min.The particle size of the sample is about 14-25 nm.The P-E hysteresis loops are measured by means of the Sawyer-Tower test system with a compensation resistor at room temperature.The remanent polarization (Pr) and coercive electric field (Ec) of the measured PZT thin films are 47.7 μC/cm2 and 18 kV/cm,respectively.The relative dielectric constant εr and the dissipation factor tgδ of the PZT thin films were measured with an LCR meter and were found to be 158 and 0.04-0.005,respectively.

  2. Electrochemical preparation of hematite nanostructured films for solar hydrogen production

    Directory of Open Access Journals (Sweden)

    Ebadzadeh T.

    2012-10-01

    Full Text Available Photoelectrochemical water splitting is a clean and promising technique for using a renewable source of energy, i.e., solar energy, to produce hydrogen. In this work electrochemical formation of iron oxyhydroxide and its conversion to hematite (α- Fe2O3 through thermal treatment have been studied. Oxyhydroxide iron compounds have been prepared onto SnO2/F covered glass substrate by potential cycling with two different potential sweep rate values; then calcined at 520 °C in air to obtain α-Fe2O3 nanostrutured films for their implementation as photoanode in a photoelectrochemical cell. X-ray diffraction analysis allowed finding that iron oxides films have nanocrystalline character. Scanning electron microscopy revealed that films have nanostructured morphology. The obtained results are discussed considering the influence of potential sweep rate employed during the preparation of iron oxyhydroxide film on optical, structural and morphological properties of hematite nanostructured films. Results show that films have acceptable characteristics as photoanode in a photoelectrochemical cell for hydrogen generation from water.

  3. A comparative investigation on structure and multiferroic properties of bismuth ferrite thin films by multielement co-doping

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Guohua; Tan, Guoqiang, E-mail: tan3114@163.com; Luo, Yangyang; Liu, Wenlong; Xia, Ao; Ren, Huijun

    2014-12-15

    Highlights: • Multielement (Tb, Cr and Mn) co-doped BiFeO{sub 3} films were fabricated by CSD method. • Multielement co-doping induces a structural transition. • It is found effective to stabilize the valence of Fe ions at +3 by the strategy. • The co-doping at A/B-sites gives rise to the superior multiferroic properties. - Abstract: (Tb, Cr and Mn) multielement co-doped BiFeO{sub 3} (BTFCMO) thin films were prepared by the chemical solution deposition method on fluorine doped tin oxide (FTO) substrates. X-ray diffraction, Rietveld refinement and Raman analyses revealed that a phase transition from rhombohedral to triclinic structure occurs in the multielement co-doped BiFeO{sub 3} films. It is found that the doping is conducive to stabilizing the valence of Fe ions and reducing leakage current. In addition, the highly enhanced ferroelectric properties with a huge remanent polarization (2P{sub r}) of 239.6 μC/cm{sup 2} and a low coercive field (2E{sub c}) of 615.6 kV/cm are ascribed to the well film texture, the structure transition and the reduced leakage current by the co-doping. Moreover, the structure transition is the dominant factor resulting in the significant enhancement observed in magnetization (M{sub s} ∼ 10.5 emu/cm{sup 3}), owing to the collapse of the space-modulated spin structure. In this contribution, these results demonstrate that the multielement co-doping is in favor of the enhanced multiferroic properties of the BFO films for possible multifunctional applications.

  4. Texture control and growth mechanism of WSe2 film prepared by rapid selenization of W film

    Science.gov (United States)

    Li, Hongchao; Gao, Di; Li, Kun; Pang, Mengde; Xie, Senlin; Liu, Rutie; Zou, Jianpeng

    2017-02-01

    The tungsten diselenide (WSe2) films with different orientation present unique properties suitable for specific applications, such as WSe2 with a C-axis⊥substrate for optoelectronics and WSe2 with a C-axis // substrate for electrocatalysts. Orientation control of WSe2 is essential for realizing the practical applications. In this letter, a WSe2 film has been prepared via rapid selenization of a magnetron-sputtered tungsten (W) film. The influence of the magnetron-sputtered W film on WSe2 film growth was studied systematically. Scanning electron microscopy, X-ray diffractometry and high-resolution transmission electron microscopy were used to evaluate the morphology, microstructure and phase composition of the W and WSe2 films. The substrate temperature has a significant effect on the W film phase composition, but little effect on the WSe2 film orientation. The WSe2 orientation can be controlled by changing the W film microstructure. A dense W film that is deposited at low pressure is conducive to the formation of WSe2 with a C-axis⊥substrate, whereas a porous W film deposited at high pressure favors the formation of WSe2 with a C-axis // substrate. A growth model for the WSe2 film with different texture has been proposed based on the experimental results. The direction of selenium (Se) vapor diffusion differs at the top and side surfaces. This is a key factor for the preparation of anisotropic WSe2 films. Highly oriented WSe2 films with a C-axis⊥substrate grow from the dense W film deposited at low pressure because Se vapor can only diffuse into the W film from the top surface where it is converted into selenide. Highly oriented WSe2 with a C-axis // substrate can be achieved for the porous W film that is deposited at high pressure because the nanopores provide a fast transmission tunnel for Se vapor diffusion. These findings will contribute to the controlled fabrication of WSe2 film and provide a theoretical basis for its application.

  5. Preparation and characterization of polymer-clay nanocomposite films

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Polymer/clay nanocomposite films were prepared by means of electrodeposition of aqueous suspension including cathodic electrophoretic acrylic resin (CEAR) and Na+-montmorillonite (NMMT). Studies of XRD,SEM and TEM indicated well-dispersed NMMT platelets in the films prepared. The ideal dispersity achieved was thought to be the result of aqueous compatibility between CEAR molecules and NMMT platelets and the result of the water-involved process as well. The modulus and strength of the polymer/clay nanocomposite coatings tested by tensile testing and nano-indentation were effectively improved compared to those of the virgin CEAR film. In addition,the adhesion strength,flexibility and water-resistance represented by Chinese national standard (GB) kept the best grades.

  6. Preparation and magnetization reversal of exchange bias structured thin films

    Energy Technology Data Exchange (ETDEWEB)

    Hamann, Christine; McCord, Jeffrey; Moench, Ingolf; Kaltofen, Rainer; Gemming, Thomas; Schaefer, Rudolf; Schultz, Ludwig [Leibniz Institute for Solid State and Materials Research, Dresden (Germany)

    2008-07-01

    Magnetically patterned thin films of NiFe/IrMn/Ta-NiFe/IrMnO{sub x} with laterally modulated unidirectional anisotropy were prepared by local oxidation of the antiferromagnetic IrMn layer. Varying the lateral dimensions and orientation with respect to the anisotropy modulation, the films exhibit different magnetization reversal behaviors. While stripes aligned parallel to the unidirectional anisotropy direction display a spin valve-like two step hysteresis loop, perpendicular orientation lead to a single step shifted hysteresis loop. Magnetic domain observation reveals separate switching of the stripes for the parallel alignment and simultaneous reversal for the perpendicular orientation. By decreasing the lateral dimensions, quasi-domain states have been observed. The presented magnetic data of the exchange biased-patterned films show that we did succeed in creating an alternative method for the preparation of materials with new hybrid properties.

  7. Preparation of DNA films for studies under vacuum conditions

    DEFF Research Database (Denmark)

    Smialek, M. A.; Balog, Richard; Jones, N. C.;

    2010-01-01

    Experiments were carried out to determine the optimum conditions required for the preparation of uniform films of supercoiled plasmid DNA to be used in irradiation experiments under high vacuum conditions. Investigations reveal that significant damage to the DNA molecules occurs due to the evacua...

  8. Synthesis and Structural Characterization of Cu Substituted Ni-Zn Nano-Ferrites Prepared By Citrate-Gel Auto Combustion Technique

    Directory of Open Access Journals (Sweden)

    N. Hari Kumar

    2014-07-01

    Full Text Available The ferrite nano particles having chemical formula Ni0.2CuxZn0.8-xFe2O4 (where x=0.0 to 0.8 with step of 0.2 were synthesized by Citrate-Gel Auto Combustion method at low temperature. The synthesized powders were sintered at 500oC for 4 hours in air and characterised by XRD, SEM with EDS. XRD analysis of prepared samples were confirmed the single phase cubic spinel Structure. The crystallite size (D of prepared ferrites were in the range of 24-73nm. The values of lattice parameter (a decreased and X-ray density (dx were increased with the increasing of Cu substitution. The surface morphology of the prepared samples was investigated by Scanning Electron Microscope(SEM. An elemental composition of the samples was studied by Energy Dispersive Spectroscopy(EDS. The observed results can be explained on the basis of composition and crystal size.

  9. Preparation and properties of cellulose nanocrystals reinforced collagen composite films.

    Science.gov (United States)

    Li, Weichang; Guo, Rui; Lan, Yong; Zhang, Yi; Xue, Wei; Zhang, Yuanming

    2014-04-01

    Collagen films have been widely used in the field of biomedical engineering. However, the poor mechanical properties of collagen have limited its application. Here, rod-like cellulose nanocrystals (CNCs) were fabricated and used to reinforce collagen films. A series of collagen/CNCs films were prepared by collagen solution with CNCs suspensions homogeneously dispersed at CNCs: collagen weight ratios of 1, 3, 5, 7, and 10. The morphology of the resulting films was analyzed by scanning electron microscopy (SEM), the enhancement of the thermomechanical properties of the collagen/CNCs composites were demonstrated by thermal gravimetric analysis (TGA) and mechanical testing. Among the CNCs contents used, a loading of 7 wt % led to the maximum mechanical properties for the collagen/CNCs composite films. In addition, in vitro cell culture studies revealed that the CNCs have no negative effect on the cell morphology, viability, and proliferation and possess good biocompatibility. We conclude that the incorporation of CNCs is a simple and promising way to reinforce collagen films without impairing biocompatibility. This study demonstrates that the composite films show good potential for use in the field of skin tissue engineering.

  10. Effect of Ni content on the structural, morphological and magnetic properties of spray deposited Ni–Zn ferrite thin films

    Energy Technology Data Exchange (ETDEWEB)

    Kumbhar, S.S.; Mahadik, M.A.; Mohite, V.S.; Hunge, Y.M.; Rajpure, K.Y.; Bhosale, C.H., E-mail: chbhosale@gmail.com

    2015-07-15

    Graphical abstract: The Ni{sub x}Zn{sub 1−x}Fe{sub 2}O{sub 4} (where x = 0.0, 0.2, 0.4, 0.6, 0.8, 1.0) thin films were prepared by spray pyrolysis technique onto the quartz substrates. The composition x = 0.4 shows the formation of the compact grain structure and highest saturation magnetization of 143 emu/cm{sup 3}. - Highlights: • Synthesis of nanocrystalline Ni{sub x}Zn{sub 1−x}Fe{sub 2}O{sub 4} thin films. • Influence of Ni substitution on physicochemical properties. • Electrical conductivity arises mainly from the grain boundary. • The highest saturation magnetization is 143 emu/cm{sup 3} for x = 0.4. - Abstract: The Ni{sub x}Zn{sub 1−x}Fe{sub 2}O{sub 4} thin films have been prepared using a simple spray pyrolysis technique. The X-ray diffraction studies reveal that, the films are polycrystalline with spinel structure. The lattice parameters vary in the range of 8.35–8.48 Å with composition (x) obeying Vegard’s rule. SEM and AFM studies show that the surface of the films exhibit a smooth, compact and a pin hole free morphology. Raman spectra indicate first order Raman active modes; A{sub 1g} (λ = 334 cm{sup −1}); E{sub g} (λ = 148 cm{sup −1}) and T{sub 2g} (λ = 699) of the Ni{sub x}Zn{sub 1−x}Fe{sub 2}O{sub 4}. The investigation on dielectric constant, dielectric loss tangent and ac conductivity was carried out in the frequency range 20 Hz–1 MHz at room temperature. The linear nature of the AC conductivity shows small polaron type of hopping mechanism. The saturation magnetization increases up to x = 0.4 (143 emu/cm{sup 3}), which decreases for higher x.

  11. 镍铁氧体/聚苯胺复合材料的制备及其性能%Preparation and properties of nickel ferrite-polyaniline composites

    Institute of Scientific and Technical Information of China (English)

    赵海涛; 张罡; 马瑞廷; 李喜坤

    2011-01-01

    采用超声场下原位聚合法制备镍铁氧体/聚苯胺复合材料,并采用x射线衍射仪(XRD)和HP8510网络分析仪研究其结构和电磁性能.结果表明:十二烷基苯磺酸(DBSA)掺杂后的聚苯胺是部分结晶的,镍铁氧体与聚苯胺分子链之间存在某些相瓦作用;与聚苯胺相比,镍铁氧体/聚苯胺复合材料的介电损耗角正切值tanδ与磁损耗角正切值tanδ都增大;镍铁氧体含量为5%和15%(质量分数)的复合材料分别具有最大的tanδ暝值和最大tanδ值;镍铁氧体含量为15%的试样在8~18 GHz范围内综合吸波性能最好,具有最大衰减-23.4 dB,-8 dB带宽为5.73 GHz.%The nickel ferrite/polyaniline composites were prepared by in-situ polymerization method under the ultrasonic field. The structural characteristics and electromagnetic properties of the composites were analyzed by X-ray diffractometry (XRD) and HP8510 network analyzer, respectively. The results indicate that DBSA doped polyaniline has some degree of crystallinity. There is some interaction between the nickel ferrite particles and the polyaniline chains. The dielectric loss tangent tanδε and magnetic tanδm loss tangent of the nickel ferrite/polyaniline composites are higher than those of polyaniline. The composites with ferrite content of 5% and 15% (mass fraction) have the maximum tanδε and tanδm values, respectively. The composite with ferrite content of 15% shows better electromagnetic wave absorbing property with minimum reflection loss of-23.4 dB, and the bandwidth of-8 dB is 5.73 GHz.

  12. Preparation and Characterization of K-Carrageenan/Nanosilica Biocomposite Film

    Directory of Open Access Journals (Sweden)

    Lokesh R. Rane

    2014-01-01

    Full Text Available The purpose of this study is to improve the performance properties of K-carrageenan (K-CRG by utilizing nanosilica (NSI as the reinforcing agent. The composite films were prepared by solution casting method. NSI was added up to 1.5% in the K-CRG matrix. The prepared films were characterized for mechanical (tensile strength, tensile modulus, and elongation at break, thermal (differential scanning calorimetry, thermogravimetric analysis, barrier (water vapour transmission rate, morphological (scanning electron microscopy, contact angle, and crystallinity properties. Tensile strength, tensile modulus, and crystallinity were found to have increased by 13.8, 15, and 48% whereas water vapour transmission rate was found to have decreased by 48% for 0.5% NSI loaded K-CRG composite films. NSI was found to have formed aggregates for concentrations above 0.5% as confirmed by scanning electron microscopy. Melting temperature, enthalpy of melting, and degradation temperature of K-CRG increased with increase in concentration of NSI in K-CRG. Contact angle also increased with increase in concentration of NSI in K-CRG, indicating the decrease in hydrophilicity of the films improving its water resistance properties. This knowledge of the composite film could make beneficial contributions to the food and pharmaceutical packaging applications.

  13. Preparation and Characteristics of Biodegradable Polyurethane/Clay Nanocomposite Films

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seong Woo [Kyonggi University, Suwon (Korea, Republic of)

    2013-06-15

    Biodegradable polyurethane (PU)/clay nanocomposite films were prepared via extrusion compounding process followed by casting film process. Organically modified montmorillonite (denoted as C30B) with a large amount of hydroxyl groups on its surface was used for the formation of strong bonding with PU resin. From both XRD analysis and TEM observations, the intercalated and exfoliated structure, and dispersion state of silicate platelets in the compounded nanocomposite films were confirmed. In addition, the rheological and tensile properties, optical transparency, oxygen permeability of the prepared nanocomposites were investigated as a function of added nanoclay content, and moreover based on these results, the correlation between the morphology and the resulting properties of the nanocomposites could be presented. The inclusion of nanoclays at appropriate content resulted in remarkable improvement in the nanocomposite performance including tensile modulus, elongation, transparency, and oxygen barrier property, however at excess amount of nanoclays, reduction or very slight increase was observed due to poor dispersion. The biodegradability of the prepared nanocomposite film was evaluated by examining the deterioration in the barrier and tensile properties during degradation period under compost.

  14. Nanodisperse Nickel Ferrite: Methods of Production, Structure and Magnetic Properties

    National Research Council Canada - National Science Library

    N Zaporina; J Grabis; M Maiorov; A Krumina; G Heidemane; D Bocharov

    2012-01-01

      Nanodisperse Nickel Ferrite: Methods of Production, Structure and Magnetic Properties The nickel ferrite nanoparticles were prepared using combustion synthesis and plasma chemical synthesis based on evaporation of coarse-grained...

  15. Ferrite microwave electronics Citations from the NTIS data base

    Science.gov (United States)

    Reed, W. E.

    1980-07-01

    Research reports on single crystals, thin films, dielectrics, semiconductor devices, integrated circuits, phase shifters, and waveguide components are cited. Studies on the microwave properties of ferrites are included.

  16. Preparation and characterization of DNA films induced by UV irradiation.

    Science.gov (United States)

    Yamada, Masanori; Kato, Kozue; Nomizu, Motoyoshi; Sakairi, Nobuo; Ohkawa, Kousaku; Yamamoto, Hiroyuki; Nishi, Norio

    2002-03-15

    Large amounts of DNA-enriched materials, such as salmon milts and shellfish gonads, are discarded as industrial waste. We have been able to convert the discarded DNA to a useful material by preparing novel DNA films by UV irradiation. When DNA films were irradiated with UV light, the molecular weight of DNA was greatly increased. The reaction was inhibited by addition of the radical scavenger galvinoxyl suggesting that the DNA polymerization with UV irradiation proceeded by a radical reaction. Although this UV-irradiated DNA film was water-insoluble and resistant to hydrolysis by nuclease, the structure of the DNA film in water was similar to non-irradiated DNA and maintained B-form structure. In addition, the UV-irradiated DNA film could effectively accumulate and condense harmful DNA-intercalating compounds, such as ethidium bromide and acridine orange, from diluted aqueous solutions. The binding constant and exclusion number of ethidium bromide for UV-irradiated DNA were determined to be 6.8 +/- 0.3 x 10(4) M(-1) and 1.6 +/- 0.2, respectively; these values are consisted with reported results for non-irradiated DNA. The UV-irradiated DNA films have potential uses as a biomaterial filter for the removal of harmful DNA intercalating compounds.

  17. Preparation and characterisation of compositionally graded SmCo films

    Science.gov (United States)

    Dias, Andre; Gomez, Gabriel; Givord, Dominique; Bonfim, Marlio; Dempsey, Nora M.

    2017-05-01

    A compositionally graded SmCo film has been prepared by magnetron sputtering using a Co target partially covered by a Sm foil. The film was deposited onto a 100 mm thermally oxidised Si substrate and then annealed ex-situ. The SmCo film has been used as a test sample to validate an in-house developed scanning MOKE (Magneto-Optic Kerr effect) system incorporating a pulsed magnetic field source capable of producing fields as high as 10 T. A 2D array of hysteresis loops was measured across the entire wafer. The evolution in coercivity measured along a selected 1D strip of the sample is correlated with changes in composition and crystallographic structures measured using Energy Dispersive Spectroscopy and X-ray diffraction. The high field Scanning MOKE system holds much potential for optimizing the extrinsic properties of known hard magnetic phases as well as in the search for new hard magnetic phases.

  18. Anisotropic Magnetoresistance of Cobalt Films Prepared by Thermal Evaporation

    Directory of Open Access Journals (Sweden)

    Yuttanun PANSONG

    2005-01-01

    Full Text Available Cobalt films on silicon substrates were prepared by thermal evaporation. By evaporating 0.05 g of cobalt for 80-240 s, a thickness from 21.1 to 67.7 nm was obtained with a deposition rate about 0.26-0.32 nm per second. The 29 nm-thick cobalt film exhibited magnetoresistance (MR ranging from -0.0793% (field perpendicular to the current to +0.0134% (field parallel to the current with saturation in a 220 mT magnetic field. This MR was attributed to anisotropic magnetoresistance (AMR since changing the angle between the field and the current (θ gave rise to a change in the electrical resistance (Rθ. The results agreed with the theory since the plot between Rθ and cos2θ could be linearly fitted. AMR was not observed in non-ferromagnetic gold films whose resistance was insensitive to the angle between the current and magnetic field.

  19. PREPARATION AND PROPERTIES OF CHITOSAN/LIGNIN COMPOSITE FILMS

    Institute of Scientific and Technical Information of China (English)

    Long Chen; Chang-yu Tang; Nan-ying Ning; Chao-yu Wang; Qiang Fu; Qin Zhang

    2009-01-01

    Biodegradable composite films based on chitosan and lignin with various composition were prepared via the solution-casting technique.FT-IR results indicate the existence of hydrogen bonding between chitosan and lignin,and SEM images show that lignin could be well dispersed in chitosan when the content of lignin is below 20 wt% due to the strong interfacial interaction.As a result of strong interaction and good dispersion,the tensile strength,storage modulus,thermal degradation temperature and glass transition temperature of chitosan have been largely improved by adding lignin.Our work provides a simple and cheap way to prepare fully biodegradable chitosan/lignin composites,which could be used as packaging films or wound dressings.

  20. Preparation and Properties of Cereal-Metal Complex Films

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    1 Results Various kinds of biodegradable polymer materials have been researched[1]. In our previous papers,cereals such as wheat,buckwheat,glutinous rice and nonglutinous rice were polycondenced with citric acid and polysilicic acid to prepare copolymer films respectively[2,3].These copolymer fims have relatively good mechanical properties but the water proofness is not so good.Recently,some cereals such as wheat,glutinous rice,nonglutinous rice,kaoliang,millet and maize were reacted with copper chlorid...

  1. 共沉淀法锰锌铁氧体的制备及其磁性能%Preparation and magnetic performance of Mn-Zn ferrites by coprecipitation method

    Institute of Scientific and Technical Information of China (English)

    赵慧君; 张娟; 范积伟

    2011-01-01

    Mn - Zn ferrite precursor powder was prepared by co-precipitation method. The Mn - Zn ferrite was obtained by sintering after being pressed,and its particle size of ferrite precursor was analyzed. XRD and magnetic properties of Mn -Zn ferrite were tested and analyzed. Results showed that uniformly distributed nano-particles can be obtained by chemical co-precipitation method under suitable conditions. After sintering,the sample is in a single phase of Mn - Zn ferrite spinel. The prepared Mn - Zn ferrite possessed high magnetic susceptibility and standard hysteresis loop. The magnetic susceptibility of ferrite increased gradually with the zinc volume reducing and the iron content increasing.%采用共沉淀法制备了锰锌铁氧体前驱体粉末,对其进行压块处理后,通过烧结得到锰锌铁氧体.测试分析了锰锌铁氧体前驱体粉末的粒度,并对锰锌铁氧体的X射线衍射及磁性能进行了测试与分析.结果表明:在适当的条件下,采用化学共沉淀法,可以制得分布均匀的纳米级锰锌铁氧体前驱体微粒.经过烧结的样品为单一的尖晶石相锰锌铁氧体.所制得的锰锌铁氧体具有较高的磁化率,标准的磁滞回线,锰锌铁氧体的磁化率随着含锌量的降低、含铁量的增加而逐渐升高.

  2. Doped Titanium Dioxide Films Prepared by Pulsed Laser Deposition Method

    Directory of Open Access Journals (Sweden)

    Juguang Hu

    2012-01-01

    Full Text Available TiO2 was intensively researched especially for photocatalystic applications. The nitrogen-doped TiO2 films prepared by pulsed laser deposition (PLD method were reviewed, and some recent new experimental results were also presented in this paper. A new optical transmission method for evaluating the photocatalystic activity was presented. The main results are (1 PLD method is versatile for preparing oxide material or complex component films with excellent controllability and high reproducibility. (2 Anatase nitrogen-doped TiO2 films were prepared at room temperature, 200°C, and 400°C by PLD method using novel ceramic target of mixture of TiN and TiO2. UV/Vis spectra, AFM, Raman spectra, and photocatalystic activity for decomposition of methyl orange (MO tests showed that visible light response was improved at higher temperature. (3 The automatic, continuous optical transmission autorecorder method is suitable for detecting the photodecomposition dynamic process of organic compound.

  3. Preparation of insoluble fibroin films and its tensile property

    Institute of Scientific and Technical Information of China (English)

    Lü Qiang; CAO Chuanbao; ZHAI Huazhang; ZHU Hesun

    2004-01-01

    Silk fibroin is becoming a promising biomaterial because of its excellent biocompatibility. However, the regenerated fibroin is usually soluble in water and its mechanical properties should be improved. Although many methods, such as adding other polymers or treating with methanol, can ameliorate the mechanical properties and insolubility, the biocompatibility of fibroin is usually damaged in these processes. In this article, it is first reported that the insoluble fibroin films are directly prepared without methanol treatment. According to the results of Fourier transform infrared spectroscope (FTIR) and the X-ray diffraction (XRD), the amount of β-sheet conformation increased with the increasing of concentration. When fibroin films are dried from 15 wt% at 60℃, the films become insoluble in water. More importantly, The tensile strength and elongation of the insoluble fibroin films dried from 15% solution at 60℃ reached 15.9 MPa and 49.4% respectively in the wet state, which is distinctly superior to the fibroin films treated with methanol.

  4. Effect of Perovskite Film Preparation on Performance of Solar Cells

    Directory of Open Access Journals (Sweden)

    Yaxian Pei

    2016-01-01

    Full Text Available For the perovskite solar cells (PSCs, the performance of the PSCs has become the focus of the research by improving the crystallization and morphology of the perovskite absorption layer. In this thesis, based on the structure of mesoporous perovskite solar cells (MPSCs, we designed the experiments to improve the photovoltaic performance of the PSCs by improved processing technique, which mainly includes the following two aspects. Before spin-coating PbI2 solution, we control the substrate temperature to modify the crystal quality and morphology of perovskite films. On the other hand, before annealing, we keep PbI2 films for the different drying time at room temperature to optimize films morphology. In our trials, it was found that the substrate temperature is more important in determining the photovoltaic performance than drying time. These results indicate that the crystallization and morphology of perovskite films affect the absorption intensity and obviously influence the short circuit current density of MPSCs. Utilizing films prepared by mentioning two methods, MPSCs with maximum power conversion efficiency of over 4% were fabricated for the active area of 0.5 × 0.5 cm2.

  5. Preparation and properties of evaporated CdTe films

    Science.gov (United States)

    Bube, R. H.; Fahrenbruch, A. L.; Chien, K. F.

    1987-07-01

    Previous work on evaporated CdTe films for photovoltaics showed no clear path to successful p-type doping of CdTe during deposition. Post-deposition annealing of the films in various ambients thus was examined as a means of doping. Anneals were done in Te, Cd, P, and As vapors and in vacuum, air and Ar, all of which showed large effects on series resistance and diode parameters. With As, series resistance values of In/p-CdTe/graphite structures decreased markedly. This decrease was due to a decrease in grain boundary and/or back contact barrier height, and thus was due to large increases in mobility; the carrier density was not altered substantially. Although the series-resistance decreases were substantial, the diode characteristics became worse. The decreases were not observed when CdS/CdTe cells were fabricated on Te vapor-annealed films. Preparation of ZnO films by reactive evaporation yielded promising results. Deposition of p-ZnTe films by hot-wall vapor evaporation, using conventional techniques, yielded acceptable specimens.

  6. Rain Erosion Behavior of Silicon Dioxide Films Prepared on Sapphire

    Institute of Scientific and Technical Information of China (English)

    Liping FENG; Zhengtang LIU; Wenting LIU

    2005-01-01

    Silicon dioxide (SiO2) films were prepared on sapphire (α-Al2O3) by radio frequency magnetron reactive sputtering in order to in crease both transmission and rain erosion resistant performance of infrared domes of sapphire. Composition and structure of SiO2 films were analyzed by X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD),respectively. The transmittance of uncoated and coated sapphire was measured using a Fourier transform infrared(FTIR) spectrometer. Rain erosion tests of the uncoated and coated sapphire were performed at 211 m/s impact velocity with an exposure time ranging from 1 to 8 min on a whirling arm rig. Results show that the deposited films can greatly increase the transmission of sapphire in mid-wave IR. After rain erosion test, decreases in normalized transmission were less than 1% for designed SiO2 films and the SiO2 coating was strongly bonded to the sapphire substrate. In addition, sapphires coated with SiO2 films had a higher transmittance than uncoated ones after rain erosion.

  7. Preparation and characterization of polyimide/silica hybrid films

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ming-yan; ZENG Shu-jin; DONG Tie-quan; ZHOU Sheng; FAN Yong; ZHANG Xiao-hong; LEI Qing-quan

    2006-01-01

    A kind of hybrid polyimide films was prepared by synthesizing poly( amic acid ) /Silica matrix resin through sol-gel technique and then followed by positing it on a silex glass plate and drying at high temperature.The effect of silica content on the corona-resistant property of the films was studied. The miscibility between the organic and inorganic phases and its effect on the corona-resistant property were investigated with aminopropyltriethoxysilane, which served as a coupling agent, added into the polyimide composite system. The chemical structure and the surface morphology of the films were characterized by FTIR and AFM respectively. The corona-resistant property of the films was tested by a rod-plate electrode. It proved that the corona-resistant property was enhanced with silica content. It also turned ont that the improvement of the miscibility between the two phases due to the presence of covalent force as a result of the addition of the coupling agent had, to some extent,effect on the corona-resistant property of the films. Furthermore, a theory on the corona-resistant property was put forward preliminarily.

  8. Antiferromagnetic coupling between spinel ferrite and {alpha}-Fe layers in Fe{sub 3-{delta}O4}/MgO/Fe(0 0 1) epitaxial films

    Energy Technology Data Exchange (ETDEWEB)

    Yanagihara, Hideto; Toyoda, Yuta; Kita, Eiji [Institute of Applied Physics, University of Tsukuba, Ibaraki 305-8573 (Japan)

    2011-02-16

    We have investigated interlayer exchange coupling (IEC) in epitaxial films of both Fe{sub 3}O{sub 4}/MgO/Fe(0 0 1) and {gamma}-Fe{sub 2}O{sub 3}/MgO/Fe(0 0 1). Depending on the thickness of the MgO spacer, both systems exhibit strong antiferromagnetic IEC of -1 to -2 erg cm{sup -2}. The {gamma}-Fe{sub 2}O{sub 3}/MgO/Fe(0 0 1) trilayer exhibits the strongest IEC when the thickness of the MgO spacer is approximately 7 A, whereas the Fe{sub 3}O{sub 4}/MgO/Fe(0 0 1) trilayer exhibits the strongest IEC when the thickness of the MgO spacer is zero. The results suggest that two different types of exchange coupling exist in the magnetic trilayers which consist of metallic iron and spinel ferrite layers.

  9. Structural and magnetic properties of Mg-Zn ferrites (Mg1-xZnxFe2O4) prepared by sol-gel method

    Science.gov (United States)

    Reyes-Rodríguez, Pamela Yajaira; Cortés-Hernández, Dora Alicia; Escobedo-Bocardo, José Concepción; Almanza-Robles, José Manuel; Sánchez-Fuentes, Héctor Javier; Jasso-Terán, Argentina; De León-Prado, Laura Elena; Méndez-Nonell, Juan; Hurtado-López, Gilberto Francisco

    2017-04-01

    In this study, the Mg1-xZnxFe2O4 nanoparticles (x=0-0.9) were prepared by sol-gel method. These ferrites exhibit an inverse spinel structure and the lattice parameter increases as the substitution of Zn2+ ions is increased. At lower Zn content (0.1≤x≤0.5), saturation magnetization (Ms) increases, while it decreases at higher Zn content (x≥6). The remnant magnetization (0.17-2.0 emu/g) and coercive field (6.0-60 Oe) indicate a ferrimagnetic behavior. The average core diameter of selected ferrites is around 15 nm and the nanoparticles morphology is quasi spherical. The heating ability of some Mg0.9Zn0.1Fe2O4 and Mg0.7Zn0.3Fe2O4 aqueous suspensions indicates that the magnetic nanoparticles can increase the medium temperature up to 42 °C in a time less than 10 min

  10. Effect of bismuth doping on the structural and magnetic properties of zinc-ferrite nanoparticles prepared by a microwave combustion method

    Science.gov (United States)

    Shoushtari, Morteza Zargar; Emami, Akram; Ghahfarokhi, Seyed Ebrahim Mosavi

    2016-12-01

    In this study, we examine the bismuth doping effect on the structural, magnetic and microstructural properties of zinc-ferrite nanoparticles (ZnFe2-xBixO4 with x=0.0, 0.02, 0.04, 0.06, 0.1, 0.15) which have been prepared by a microwave combustion method. The structural, morphological and electromagnetic properties and also Curie temperature of the samples were examined by x-ray powder diffraction (XRD), field emission scanning electron microscope (FESEM), vibrating sample magnetometer (VSM), and LCR meter, respectively. In order to measure the energy band gap, the FTIR spectra of the samples were also considered. The XRD patterns of the samples revealed that all of them are ZnFe2O4 structure and no additional peak was observed in their patterns. This implied that the samples were single-phase up to bismuth solubility of 0.15 in Zinc-Ferrite. The results of XRD patterns also showed that the value lattice parameter increases with increasing the bismuth doping. The FESEM results revealed an ascending trend in the size of the nanoparticles. Also considering the VSM results characterized that an increasing the bismuth doping leads to lower the saturation magnetization. The Curie temperatures of the samples were reduced as a result of increasing the amount of bismuth.

  11. Preparation of organic thin-film field effect transistor

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The organic thin-film field effect transistor was prepared through vacuum deposition by using teflon as di-electric material. Indium-tin-oxide acted as the source and drain electrodes. Copper phthalocyanine and teflon were used as the semiconductor layer and dielectric layer, respectively. The gate electrode was made of Ag. The channel length between the source and drain was 50 μm. After preparing the source and drain electrodes by lithography, the copper phthalocyanine layer, teflon layer and Ag layerwere prepared by vacuum deposition sequentially. The field effect electron mobility of the device reached 1.1×10ˉ6 cm2/(V@s), and the on/off current ratio reached 500.

  12. Preparation and properties of thin films treatise on materials science and technology

    CERN Document Server

    Tu, K N

    1982-01-01

    Treatise on Materials Science and Technology, Volume 24: Preparation and Properties of Thin Films covers the progress made in the preparation of thin films and the corresponding study of their properties. The book discusses the preparation and property correlations in thin film; the variation of microstructure of thin films; and the molecular beam epitaxy of superlattices in thin film. The text also describes the epitaxial growth of silicon structures (thermal-, laser-, and electron-beam-induced); the characterization of grain boundaries in bicrystalline thin films; and the mechanical properti

  13. [Preparation and spectroscopic properties of terbium polypropenic acid film].

    Science.gov (United States)

    Wang, Xi-gui; Wu, Hong-ying; Weng, Shi-fu; Wu, Jin-guang

    2002-12-01

    The bonding-type rare earth polymers-polypropenic-acid terbium film was prepared through the bonding way. Three-dimension fluorescence spectra showed that the optimum excitation wavelength was 306 nm, the strongest emission wavelength was 544 nm. The terbium polypropenic-acid film showed the characteristic Tb3+ emission when excited at 306 nm due to 5D4-7FJ transition (J = 6, 5, 4 and 3). The emission maximum at 544 nm was ascribed to 5D4-7F5 transition of Tb3+ and presented strong green emission. The luminescent properties of Tb3+ were not affected by polymerism of propenic-acid and the transparency of polypropenic-acid in visible light region was not affected by the dopping Tb3+. The fluorescence properties and spectroscopic properties of the terbium polypropenic-acid were investigated by excitation spectrum, emission spectrum, IR, far-IR, and Raman spectrum.

  14. Nanocrystalline silicon films prepared by laser-induced crystallization

    Institute of Scientific and Technical Information of China (English)

    傅广生; 于威; 李社强; 侯海虹; 彭英才; 韩理

    2003-01-01

    The excimer laser-induced crystallization technique has been used to investigate the preparation of nanocrystalline silicon (nc-Si) from amorphous silicon (α-Si) thin films on silicon or glass substrates. The α-Si films without hydrogen grown by pulsed-laser deposition are chosen as precursor to avoid the problem of hydrogen effluence during annealing.Analyses have been performed by scanning electron microscopy, atomic force microscopy, Raman scattering spectroscopy and high-resolution transmission-electron microscopy. Experimental results show that silicon nanocrystals can be formed through laser annealing. The growth characters of nc-Si are strongly dependent on the laser energy density. It is shown that the volume of the molten silicon predominates essentially the grain size of nc-Si, and the surface tension of the crystallized silicon is responsible for the mechanism of nc-Si growth.

  15. Preparation of nickel ferrite/carbon nanotubes composite by microwave irradiation technique for use as catalyst in photo-fenton reaction

    Energy Technology Data Exchange (ETDEWEB)

    Foletto, E.L.; Rigo, C.; Severo, E.C.; Mazutti, M.A.; Dotto, G.L.; Jahn, S.L.; Sales, J.C. [Universidade Federal de Santa Maria (UFSM), RS (Brazil); Chiavone-Filho, O. [Universidade Federal do Rio Grande do Sul (UFRGS), RS (Brazil); Gundel, A.; Lucchese, M. [Universidade Federal do Pampa (UNIPAMPA), Bage, RS (Brazil)

    2016-07-01

    Full text: Nickel ferrite/multi-walled carbon nanotubes (NiFe2O4/MWCNTs) composite has been rapidly synthesized via microwave irradiation technique. The structural properties of the formed product was investigated by X-ray diffraction (XRD), N2 adsorption/desorption isotherms, thermogravimetric analysis (TGA), Raman spectroscopy and, scanning electron microscopy (SEM). The catalytic behavior of composite material was evaluated by the degradation of Amaranth dye in the photo-Fenton reaction under visible light irradiation. The overall results showed that the prepared composite was successfully synthesized, demonstrating good performance in the dye degradation, with higher degradation rate compared to the NiFe2O4. The high efficiency in dye degradation can be attributed to synergism between NiFe2O4 and MWCNTs. Therefore, NiFe2O4/MWCNTs composite can be used as promising photo-Fenton catalyst to degrade Amaranth dye from aqueous solutions. (author)

  16. Influence of the preparation route on the magnetic and structural properties of cobalt ferrites; Influencia da rota de preparacao nas propriedades estruturais e magneticas das ferritas de cobalto

    Energy Technology Data Exchange (ETDEWEB)

    Revoredo Junior, Frederico Alves; Silva Junior, Jose Holanda da; Hernandez, Eduardo Padron, E-mail: fredrevoredo@hotmail.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil)

    2014-07-01

    Cobalt ferrite nanoparticles were produced using two methods of preparation, co-precipitation and reaction in the solid state. In synthesis made by solid state reaction was performed by heat treatment at 1200 ° C for four hours alternating with triturations to increase the efficiency of the process. The synthesis by coprecipitation was made with different flows of addition of alkali (NaOH). All samples were structurally characterized by X-ray diffraction and the average size of the crystals was obtained by Scherrer's formula and the Williamson-Hall method. The magnetic measurements were made as a function of applied magnetic field and temperature. Qualitative analyzes of energy dispersive spectroscopy defined the elements of sampling and analysis. Finally, Mössbauer spectroscopy analysis defined the magnetic character of the samples. (author)

  17. Nanostructure Study of TiO2 Films Prepared by Dip Coating Process

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The microstructure properties of the sol-gel derived TiO2 films were studied by the atomic force microscopy (AFM).The films were prepared by dip coating process. The optical properties of the films were explained on the basis ofthe microstructure of the films.

  18. Epitaxial ternary nitride thin films prepared by a chemical solution method

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Hongmei [Los Alamos National Laboratory; Feldmann, David M [Los Alamos National Laboratory; Wang, Haiyan [TEXAS A& M; Bi, Zhenxing [TEXAS A& M

    2008-01-01

    It is indispensable to use thin films for many technological applications. This is the first report of epitaxial growth of ternary nitride AMN2 films. Epitaxial tetragonal SrTiN2 films have been successfully prepared by a chemical solution approach, polymer-assisted deposition. The structural, electrical, and optical properties of the films are also investigated.

  19. Preparation and properties of CuInS{sub 2} thin film prepared from electroplated precursor

    Energy Technology Data Exchange (ETDEWEB)

    Onuma, Yoshio; Takeuchi, Kenji; Ichikawa, Sumihiro; Suzuki, Yasunari; Fukasawa, Ryo; Matono, Daisuke; Nakamura, Kenji; Nakazawa, Masao; Takei, Koji [Core Technology Research Laboratory, Shinko Electric Industries Co., Ltd., 80 Oshimada, Nagano 381-2287 (Japan)

    2006-01-15

    Thin CuInS{sub 2} films were prepared by sulfurization of Cu/In bi-layers. First, the precursor layer was electroplated onto the treated surface of Mo-coated glass. Observation of the cross-section prepared by focused ion beam (FIB) etching revealed that the void-free film was initially formed on the top surface of the precursor layer and continued to grow until the advancing front of the film reached the Mo layer. The nucleation of voids near the bottom of the CuInS{sub 2} film followed. To determine whether the condition of the Cu/In alloy influences the CuInS{sub 2} quality we investigated the Cu/In alloy state using FIB. We found that the annealed precursor of low Cu/In ratio (1.2) has several voids in the mid position in the layer compared with Cu-rich precursor (1.6). The cross-sectional view of the Cu-rich absorber layer is uniform compared with the low copper absorber layer. Thin film solar cells were fabricated using the CuInS{sub 2} film (Cu/In ratio: 1.2) as an optical absorber layer. It was found that the optimization of a sulfurization period is important in order to improve the cell efficiency. We have not yet obtained good results with high Cu-rich absorber because of a blister problem. This blister was found before sulfurization. So, we are going to solve this blister problem before sulfurization.

  20. Photocatalytic ability of TiO2 porous film prepared by modified spray pyrolysis deposition technique

    National Research Council Canada - National Science Library

    SUGIYAMA, Osamu; OKUYA, Masayuki; KANEKO, Shoji

    2009-01-01

    In a spray pyrolysis deposition (SPD) technique, deposition of film material and formation of surface structure are simultaneously occur, therefore, it is suitable for the preparation of microstructure-controlled thin films...

  1. Preparation of Lead-free Thick-film Resistor Pastes

    Institute of Scientific and Technical Information of China (English)

    LUO Hui; LI Shihong; LIU Jisong; CHEN Liqiao; YING Xingang; WANG Ke

    2012-01-01

    The preparation of lead-free thick-film resistors are reported:using RuO2 and ruthenates as conductive particles,glass powders composed of B2O3,SiO2,CaO and Al2O3 as insulating phase,adding organic matter which mainly consists of ethyl cellulose and terpineol to form printable pastes.Resistors were fabricated and sintered by conventional screen-printing on 96%Al2O3 substrates,and then sintering in a belt furnace.X-ray diffraction (XRD) and electron scanning microscopy (SEM) have been used to characterize the conductive particles.The resistors exhibit good retiring stability and low temperature coefficient of resistance.Sheet resistance spans from about 80 Ω/□ to 600 Ω/□.The resistors prepared are qualified for common use.

  2. Deposition of La0.8Sr0.2Cr0.97V0.03O3 and MnCr2O4 thin films on ferritic alloy for solid oxide fuel cell application

    DEFF Research Database (Denmark)

    Mikkelsen, Lars; Chen, Ming; Hendriksen, Peter Vang;

    2007-01-01

    Single layer dense films of La0.8Sr0.2Cr0.97V0.03O3 (LSC) and MnCr2O4 with a thickness of 500 nm were deposited on a commercially available ferritic alloy (Crofer 22APU) by large-area Pulsed Laser Deposition. The deposited samples were subsequently oxidized at 1173 K for 500 h in humidified air...

  3. Tailoring magnetic and dielectric properties of rubber ferrite composites containing mixed ferrites

    Indian Academy of Sciences (India)

    M R Anantharaman; K A Malini; S Sindhu; E M Mohammed; S K Date; S D Kulkarni; P A Joy; Philip Kurian

    2001-12-01

    Rubber ferrite composites containing various mixed ferrites were prepared for different compositions and various loadings. The magnetic and dielectric properties of the fillers as well as the ferrite filled matrixes were evaluated separately. The results are correlated. Simple equations are proposed to predetermine the magnetic and dielectric properties. The validity of these equations is verified and they are found to be in good agreement. These equations are useful in tailoring the magnetic and dielectric properties of these composites with predetermined properties.

  4. Anomalous thickness-dependent strain states and strain-tunable magnetization in Zn-doped ferrite epitaxial films

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Y. J.; Bao, J.; Gao, C., E-mail: zlluo@ustc.edu.cn, E-mail: cgao@ustc.edu.cn [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230026 (China); CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026 (China); Yang, M. M.; Luo, Z. L., E-mail: zlluo@ustc.edu.cn, E-mail: cgao@ustc.edu.cn; Hu, C. S.; Chen, X. C.; Pan, G. Q. [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230026 (China); Huang, H. L. [CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026 (China); Zhang, S.; Wang, J. W.; Li, P. S.; Liu, Y.; Zhao, Y. G. [Department of Physics and State Key Laboratory of New Ceramics, Fine Processing, Tsinghua University, Beijing 100084 (China); Jiang, T.; Liu, Y. K.; Li, X. G. [Hefei National Laboratory for Physical Sciences at Microscale and Department of Physics, University of Science, Technology of China, Hefei, Anhui 230026 (China)

    2014-05-07

    A series of Zn{sub x}Fe{sub 3−x}O{sub 4} (ZFO, x = 0.4) thin films were epitaxially deposited on single-crystal (001)-SrTiO{sub 3} (STO) substrates by radio frequency magnetron sputtering. The anomalous thickness-dependent strain states of ZFO films were found, i.e., a tensile in-plane strain exists in the thinner ZFO film and which monotonously turns into compressive in the thicker films. Considering the lattice constant of bulk ZFO is bigger than that of STO, this strain state cannot be explained in the conventional framework of lattice-mismatch-induced strain in the hetero-epitaxial system. This unusual phenomenon is proposed to be closely related to the Volmer-Weber film growth mode in the thinner films and incorporation of the interstitial atoms into the island's boundaries during subsequent epitaxial growth of the thicker films. The ZFO/STO epitaxial film is found in the nature of magnetic semiconductor by transport measurements. The in-plane magnetization of the ZFO/STO films is found to increase as the in-plane compressive strain develops, which is further proved in the (001)-ZFO/PMN-PT film where the film strain state can be in situ controlled with applied electric field. This compressive-strain-enhanced magnetization can be attributed to the strain-mediated electric-field-induced in-plane magnetic anisotropy field enhancement. The above results indicate that strain engineering on magnetic oxide semiconductor ZFO films is promising for novel oxide-electronic devices.

  5. Sheet resistances of composite films prepared from chemically-reduced graphite oxides and multiwalled carbon nanotubes

    Science.gov (United States)

    Oh, Weontae; Kim, Daehan; Jeong, Euh Duck; Bae, Jong-Seong

    2013-12-01

    Graphite oxides (GOs) were spray-coated on a glass substrate to prepare the GO film, and the film was soaked in a HI aqueous solution to make a chemically-reduced GO (rGO) film. The rGOs were successfully prepared by using a chemical reduction of as-made GOs, but their surfaces were seriously damaged during the chemical treatments. The Sheet resistances of rGO and rGO/multiwalled carbon nanotube (MWNT) films were characterized as functions of the film's thickness and the number of MWNTs added to the rGO films.

  6. Electrospinning preparation, characterization and magnetic properties of cobalt-nickel ferrite (Co(1-x)Ni(x)Fe2)O4) nanofibers.

    Science.gov (United States)

    Xiang, Jun; Chu, Yanqiu; Shen, Xiangqian; Zhou, Guangzhen; Guo, Yintao

    2012-06-15

    Uniform Co(1-)(x)Ni(x)Fe(2)O(4) (x=0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) nanofibers with average diameter of 110 nm and length up to several millimeters were prepared by calcination of electrospun precursor nanofibers containing polymer and inorganic salts. The as-spun and calcined nanofibers were characterized in detail by TG-DTA, XRD, FE-SEM, TEM, SAED and VSM, respectively. The effect of composition of the nanofibers on the structure and magnetic properties were investigated. The nanofibers are formed through assembling magnetic nanoparticles with poly(vinyl pyrrolidone) as the structure-directing template. The structural characteristics and magnetic properties of the resultant nanofibers vary with chemical composition and can be tuned by adjusting the Co/Ni ratio. Both lattice parameter and particle size decrease gradually with increasing nickel concentration. The saturation magnetization and coercivity lie in the range 29.3-56.4 emu/g and 210-1255 Oe, respectively, and both show a monotonously decreasing behavior with the increase in nickel concentration. Such changes in magnetic properties can mainly be attributed to the lower magnetocrystalline anisotropy and the smaller magnetic moment of Ni(2+) ions compared to Co(2+) ions. Furthermore, the coercivity of Co-Ni ferrite nanofibers is found to be superior to that of the corresponding nanoparticle counterparts, presumably due to their large shape anisotropy. These novel one-dimensional Co-Ni ferrite magnetic nanofibers can potentially be used in micro-/nanoelectronic devices, microwave absorbers and sensing devices. Copyright © 2012 Elsevier Inc. All rights reserved.

  7. Structural, magnetic, dielectric, and electrical properties of NiFe2O4 spinel ferrite nanoparticles prepared by honey-mediated sol-gel combustion

    Science.gov (United States)

    Yadav, Raghvendra Singh; Kuřitka, Ivo; Vilcakova, Jarmila; Havlica, Jaromir; Masilko, Jiri; Kalina, Lukas; Tkacz, Jakub; Enev, Vojtěch; Hajdúchová, Miroslava

    2017-08-01

    In this study, NiFe2O4 nanoparticles were synthesized using a honey-mediated sol-gel combustion method. The synthesized nanoparticles and samples annealed at 800 °C and 1100 °C were characterized by X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and vibrating sample magnetometry (VSM). XRD and Raman spectroscopy confirmed the formation of a cubic spinel ferrite structure. FE-SEM demonstrated the octahedral morphology of the NiFe2O4 spinel ferrite nanoparticles with sizes ranging from 10 to 70 nm. Quantitative analysis based on XPS suggested a mixed spinel structure comprising NiFe2O4 nanoparticles. XPS analysis determined occupation formulae of (Ni0.212+ Fe0.443+)[Ni0.792+ Fe1.563+]O4 and (Ni0.232+ Fe0.503+)[Ni0.772+ Fe1.503+]O4, for the as-prepared NiFe2O4 nanoparticles and those annealed at 1100 °C, respectively. Magnetic measurements showed that the saturation magnetization increased with the crystallite size from 32.3 emu/g (20 nm) to 49.9 emu/g (163 nm), whereas the coercivity decreased with the crystallite size from 162 Oe (20 nm) to 47 Oe (163 nm). Furthermore, the dielectric constant, dielectric loss tangent, and AC conductivity of the NiFe2O4 nanoparticles were dependent on the frequency (1-107 Hz) and grain size. The influence of the grain size was also observed by modulus spectroscopy based on the Cole-Cole plot.

  8. 铁酸铋薄膜光伏效应研究进展%Research Progress in Photovoltaic Effect of Bismuth Ferrite Thin Films

    Institute of Scientific and Technical Information of China (English)

    周浩; 高荣礼; 符春林

    2016-01-01

    Bismuth ferrite is the only single phase multiferroic material which shows both ferroelectric and antiferromag-netic properties at room temperature and potential magneto electric effect between the two ferro orders. The ferroelectric Curie temperature and the antiferromagnetic Neel temperatures are both above room temperature. It has broad application prospects in the fields of optoelectronic devices, spin electric devices, ferroelectric random access memories, magnetoelectric memory. Be-sides, bismuth ferrite has relatively larger polarization, lower band-gap and large absorption coefficient, and theoretically may become an alternative for next generation of photovoltaic cell because of its photoelectric conversion efficiency. However, there is no clear conclusion about the mechanism of the photovoltaic effect of multiferroic Bismuth ferrite materials. And many prob- lems need to be solved because many factors can affect the photovoltaic effect, including domains, interfaces, thickness, depola-rization field, defect, polarization and so on. Based on these considerations above, we review the research progress of Bismuth ferrite thin film of the photovoltaic effect mechanism.%铁酸铋是目前唯一在室温下同时具有铁电性和反铁磁性的单相多铁性材料,并且这两种铁性有序之间存在磁电耦合效应,其铁电居里温度和反铁磁奈尔温度都远在室温以上,在光电器件、自旋电子器件、铁电随机存储器、磁电存储单元等领域有着广阔的应用前景。此外,作为一种典型的铁电材料,铁酸铋还具有较大的剩余极化强度、相对较小的带隙宽度以及较大的光吸收系数,理论上具有较大的光电转换效率,有望成为下一代太阳能光伏电池的备选材料。然而,目前有关铁酸铋材料光伏效应的机制还没有明确的定论,影响其光伏效应的因素较多,例如电畴、界面、厚度、退极化场、缺陷及极化强度等。

  9. Electromagnetic Characteristics of Mn-Zn Ferrite Nanoparticles Prepared by Modified Pechini Method%改进Pechini方法制备锰锌铁氧体纳米颗粒及其电磁特性

    Institute of Scientific and Technical Information of China (English)

    刘献明; 高文亮

    2011-01-01

    Mn-Zn ferrite nanoparticles were obtained by calcining foam gel particles at 500 ℃ which were prepared by modified Pechini method. The structural and magnetic characteristics of the as prepared samples were analyzed by XRD, TEM, ED and VSM. Compared to Mn-Zn ferrite nanoparticles fabricated by Pechini method, the results showed that Mn-Zn ferrite nanoparticles prepared by modified Pechini method exhibited good dispersibility, uniform distribution and good crystallinity, and the particlediameter is in the range of 20-40 nm; its saturation magnetization is 40. 6 emu/g at the maximum magnetic field of 10 kOe at room temperature. The electromagnetic characteristics of Mn-Zn ferrites prepared by different methods were measured by vector network analyzer in the microwave frequency range of 2-18 GHz. The Mn-Zn ferrites prepared by modified Pechini method exhibited higher dielectric constant and permeability than that of Mn-Zn ferrites prepared by conventional Pechini method.%通过改进的Pechini方法制备了泡沫凝胶颗粒,然后在500℃下煅烧得到锰锌铁氧体纳米颗粒.借用XRD、TEM、ED及VSM对其形貌、结构和磁性能进行了分析,并与Pechini方法制得的锰锌铁氧体纳米颗粒进行比较.结果表明了改进方法得到的锰锌铁氧体分散性好,尺寸均匀,晶化程度高,颗粒直径范围为20 ~40 nm;在10 kOe处磁化强度高达40.6 emu·g-1.用矢量网络分析仪研究了不同方法合成的锰锌铁氧体在2~18 GHz范围内的电磁特性,结果表明了改进Pechini方法制得的锰锌铁氧体具有相对较高的介电常数和磁导率.

  10. Controllable preparation of nanosized TiO2 thin film and relationship between structure of film and its photocatalytic activity

    Institute of Scientific and Technical Information of China (English)

    WEI; Gang; (魏刚); ZHANG; Yuanjing; (张元晶); XIONG; Rongchun; (熊蓉春)

    2003-01-01

    TiO2 nano-crystalline film and fixed bed photocatalytic reactor were prepared by the sol-gel process using tetrabutylorthotitanate as a precursor and glass tube as the substrate. XRD, AFM, SEM and thickness analysis results indicate that the preparation of nano-crystalline film can be controlled by optimizing experiment process. Under the optimized process, the phase of TiO2 in film is anatase, and the grain size is 3-4 nm. The size of particles, which is about 20-80 nm, can be controlled. The thickness of monolayer film is in nanometer grade. The thickness and particles size in films growing on nanometer film can also be controlled in nanometer grade. As a result, the crack of film can be effectively avoided. Rhodamine B degradation results using UV-Vis spectrophotometer show that the activity of nano-crystalline film in the photocatalytic reactor has a good relation with the diameter of TiO2 particles, that is, the film shows high activity when the size is 20-30 nm and greatly reduced when the size is above 60 nm. The activity of film does not decrease with the increase of film thickness, and this result indicates that nano-crystalline film has no ill influence on the transmissivity of ultraviolet light.

  11. Thin-film preparation by back-surface irradiation pulsed laser deposition using metal powder targets

    Science.gov (United States)

    Kawasaki, Hiroharu; Ohshima, Tamiko; Yagyu, Yoshihito; Ihara, Takeshi; Yamauchi, Makiko; Suda, Yoshiaki

    2017-01-01

    Several kinds of functional thin films were deposited using a new thin-film preparation method named the back-surface irradiation pulsed laser deposition (BIPLD) method. In this BIPLD method, powder targets were used as the film source placed on a transparent target holder, and then a visible-wavelength pulsed laser was irradiated from the holder side to the substrate. Using this new method, titanium oxide and boron nitride thin films were deposited on the silicon substrate. Surface scanning electron microscopy (SEM) images suggest that all of the thin films were deposited on the substrate with some large droplets irrespective of the kind of target used. The deposition rate of the films prepared by using this method was calculated from film thickness and deposition time to be much lower than that of the films prepared by conventional PLD. X-ray diffraction (XRD) measurement results suggest that rutile and anatase TiO2 crystal peaks were formed for the films prepared using the TiO2 rutile powder target. Crystal peaks of hexagonal boron nitride were observed for the films prepared using the boron nitride powder target. The crystallinity of the prepared films was changed by annealing after deposition.

  12. Preparation and characterisation of novel thick sol-gel titania film photocatalysts.

    Science.gov (United States)

    Mills, Andrew; Elliott, Nicholas; Hill, George; Fallis, David; Durrant, James R; Willis, Richard L

    2003-05-01

    The preparation and characterization of thick (9 microns), clear, mechanically robust and photocatalytically active films of nanocrystalline anatase titania are described. XRD and SEM analysis show the films comprise 13 nm particles of anatase TiO2. Thin (54 nm) films of the 'paste' TiO2, along with sol-gel titania films made by a more traditional route are also prepared and characterised. All titania films mediate the photocatalytic destruction of stearic acid with a quantum yield of 0.0016 +/- 0.0003, using either 365 nm (i.e. BLB) or 254 nm (germicidal) light. P25 TiO2 films also appear to mediate the same process with a similar formal quantum efficiency. Of all the films tested, the thick paste TiO2 films are the most ideally suited for use with near UV light, for reasons which are discussed. All the titania films tested exhibit photoinduced superhydrophilicity.

  13. Structural analysis of Y{sup 3+}-doped Mg-Cd ferrites prepared by oxalate co-precipitation method

    Energy Technology Data Exchange (ETDEWEB)

    Gadkari, A.B. [Department of Physics, GKG College, Kolhapur 416012, Maharashtra (India)], E-mail: kashokabg@yahoo.com; Shinde, T.J. [Department of Physics, KRP Kanya Mahavidylaya, Islampur 415409 (India); Vasambekar, P.N. [Department of Electronics, Shivaji University, Kolhapur 416004 (India)

    2009-04-15

    Polycrystalline ferrites of Cd{sub x}Mg{sub 1-x}Fe{sub 2}O{sub 4} (x = 0, 0.2, 0.4, 0.6, 0.8 and 1.0) with addition of 5% of yttrium has been synthesized by oxalate co-precipitation method and characterized by XRD, SEM and FTIR techniques. The samples were presintered at 700 deg. C for duration of 6 h and sintered at 1050 deg. C for 5 h. The X-ray diffraction measurements confirmed the formation of cubic spinel structure. Lattice constant, X-ray density, physical density, crystallite size, ionic radii on A-site and B-site (r{sub A}, r{sub B}), bond length on A-site and B-site (A-O, B-O) and porosity have been calculated. The lattice constant is found to increase with increase in Cd{sup 2+} content. The physical densities are about 86.96% of their X-ray density. Average crystallite size lies in the range of 28.86-32.06 nm. SEM study shows that the grain size of the samples increases with increase in Cd{sup 2+} content. The addition of Y{sup 3+} reduces the grain growth. The FTIR spectra shows two strong absorption bands in the frequency range 575-435 cm{sup -1}, on the tetrahedral and octahedral sites, respectively. Further it shows that Y{sup 3+} occupies B-sites.

  14. Fabrication and integrity test preparation of HIP-joined W and ferritic-martensitic steel mockups for fusion reactor development

    Science.gov (United States)

    Lee, Dong Won; Shin, Kyu In; Kim, Suk Kwon; Jin, Hyung Gon; Lee, Eo Hwak; Yoon, Jae Sung; Choi, Bo Guen; Moon, Se Youn; Hong, Bong Guen

    2014-10-01

    Tungsten (W) and ferritic-martensitic steel (FMS) as armor and structural materials, respectively, are the major candidates for plasma-facing components (PFCs) such as the blanket first wall (BFW) and the divertor, in a fusion reactor. In the present study, three W/FMS mockups were successfully fabricated using a hot isostatic pressing (HIP, 900 °C, 100 MPa, 1.5 hrs) with a following post-HIP heat treatment (PHHT, tempering, 750 °C, 70 MPa, 2 hrs), and the W/FMS joining method was developed based on the ITER BFW and the test blanket module (TBM) development project from 2004 to the present. Using a 10-MHz-frequency flat-type probe to ultrasonically test of the joint, we found no defects in the fabricated mockups. For confirmation of the joint integrity, a high heat flux test will be performed up to the thermal lifetime of the mockup under the proper test conditions. These conditions were determined through a preliminary analysis with conventional codes such as ANSYS-CFX for thermal-hydraulic conditions considering the test facility, the Korea heat load test facility with an electron beam (KoHLT-EB), and its water coolant system at the Korea Atomic Energy Research Institute (KAERI).

  15. Nanosized MX Precipitates in Ultra-Low-Carbon Ferritic/Martensitic Heat-Resistant Steels

    Science.gov (United States)

    Yin, Feng-Shi; Jung, Woo-Sang

    2009-02-01

    Nanosized MX precipitates in ultra-low-carbon ferritic/martensitic heat-resistant 9Cr-W-Mo-VNbTiN steels were characterized by transmission electron microscope (TEM) using carbon film replicas. The steels were prepared by vacuum induction melting followed by hot forging and rolling into plates. The plates were normalized at 1100 °C for 1 hour, cooled in air, and tempered at 700 °C for 1 hour. The results show that bimodal nanosized MX precipitates distribute densely and homogeneously in the matrix within martensitic lath after normalizing-and-tempering heat treatment. The larger nanosized MX precipitates with the size of 30 to 50 nm are rich in Nb, while the smaller ones with the size of about 10 nm contain less Nb but more V. Small addition of Ti causes an increase in the number of the larger nanosized MX precipitates. The total number density of the nanosized MX precipitates in the ultra-low-carbon ferritic/martensitic steels is measured to be over 300/ μm2, much higher than that in conventional ferritic/martensitic steels. Short-term creep test results show that the ultra-low-carbon ferritic/martensitic steels with high dense nanosized MX precipitates have much higher creep rupture strength than conventional ASME-P92 steel. The strength degradation of the ultra-low-carbon ferritic/martensitic heat-resistant steels during creep is also discussed in this article.

  16. Preparation and Characterization of InAs/Si Composite Film

    Institute of Scientific and Technical Information of China (English)

    YANG Lin; LI Guang-Hai; ZHENG Mao-Jun; ZHANG Li-De

    2000-01-01

    Composite thin films consisting of nanosized InAs particles embedded in amorphous Si matrices were prepared by radio frequency co-sputtering of InAs and Si. X-ray diffraction spectra show that the particle size of InAs increases with the increasing annealing temperature, while the particle sizes of In and As reach their maximum values at the temperature of 200℃, and decrease with the further increase of the annealing temperature. In and As can not exist in the 500℃ sample due to the sublimation of In and As and the reaction In+As→InAs. The composition of the film in different levels was analyzed. We found that only in the deep level, the mole contents of As and In conform to the stoichiometric ratio and the oxidation occurs only a few nanometers from the surface. We believe that the scarcity of In and As near the surface is due to the sublimation of In and the oxide of As.

  17. Fluoride adsorption by doped and un-doped magnetic ferrites CuCe(x)Fe(2-x)O4: Preparation, characterization, optimization and modeling for effectual remediation technologies.

    Science.gov (United States)

    Rehman, Muhammad Abdur; Yusoff, Ismail; Alias, Yatimah

    2015-12-15

    A series of doped and un-doped magnetic adsorbents CuCexFe2-xO4 (x=0.0-0.5) for fluoride were prepared with the micro-emulsion method. Fluoride adsorption was optimized for solution pH, temperature, contact time, and initial concentration and was monitored via normal phase ion chromatography (IC). The effect of concomitant anions was also explored to perform and simulate competitive fluoride adsorption in real water samples. Optimal adsorption was discovered by a simple quadratic model based on central composite design (CCD) and the response surface method (RSM). The adsorption, electrochemical and magnetic properties were compared between doped and un-doped ferrites. Doped ferrites (x=0.1-0.5) were found to be superior to un-doped ferrites (x=0) regarding the active sites, functional groups and fluoride adsorption. The characterization, optimization and application results of the doped ferrites indicated enhanced fluoride adsorption and easy separation with a simple magnet.

  18. Structure and Magnetic Properties of Fe-N Films Prepared by Dual Ion Beam Sputtering

    Institute of Scientific and Technical Information of China (English)

    诸葛兰剑; 吴雪梅; 汤乃云; 叶春兰; 姚伟国

    2001-01-01

    Fe-N films were prepared on Si substrate by dual ion beam sputtering (DIBS). It is of the films were investigated by a vibrating sample magnetometer (VSM). The structure of the films is insensitive to the ratios of N2/Ar in main ion source(MIS), and is mainly influenced by the substrate temperature (Ts).``

  19. Heat generation ability in AC magnetic field of nano MgFe{sub 2}O{sub 4}-based ferrite powder prepared by bead milling

    Energy Technology Data Exchange (ETDEWEB)

    Hirazawa, Hideyuki, E-mail: hirazawa@mat.niihama-nct.ac.j [Department of Environmental Materials Engineering, Niihama National College of Technology, Niihama 792-8580 (Japan); Aono, Hiromichi; Naohara, Takashi; Maehara, Tsunehiro [Graduate School of Science and Engineering, Ehime University, Matsuyama 790-8577 (Japan); Sato, Mitsunori [AdMeTech Co. Ltd., 2821-4, Minami-yoshida-cyo, Matsuyama 791-8042 (Japan); Watanabe, Yuji [Department of Surgery, Graduate School of Medicine, Ehime University, Toon 791-0295 (Japan)

    2011-03-15

    Nanosized MgFe{sub 2}O{sub 4}-based ferrite powder having heat generation ability in an AC magnetic field was prepared by bead milling and studied for thermal coagulation therapy applications. The crystal size and the particle size significantly decreased by bead milling. The heat generation ability in an AC magnetic field improved with the milling time, i.e. a decrease in crystal size. However, the heat generation ability decreased for excessively milled samples with crystal sizes of less than 5.5 nm. The highest heat ability ({Delta}T=34 {sup o}C) in the AC magnetic field (370 kHz, 1.77 kA/m) was obtained for fine MgFe{sub 2}O{sub 4} powder having a ca. 6 nm crystal size (the samples were milled for 6-8 h using 0.1 mm {phi} beads). The heat generation of the samples was closely related to hysteresis loss, a B-H magnetic property. The reason for the high heat generation properties of the samples milled for 6-8 h using 0.1 mm {phi} beads was ascribed to the increase in hysteresis loss by the formation of a single domain. Moreover, the improvement in heating ability was obtained by calcination of the bead-milled sample at low temperature. In this case, the maximum heat generation ({Delta}T=41 {sup o}C) ability was obtained for a ca. 11 nm crystal size sample was prepared by crystal growth during the sample calcination. On the other hand, the {Delta}T value for Mg{sub 0.5}Ca{sub 0.5}Fe{sub 2}O{sub 4} was synthesized using a reverse precipitation method decreased by bead milling. - Research highlights: > The crystal and particle size for MgFe{sub 2}O{sub 4} based ferrite were decreased by bead milling. > The highest heat ability was obtained for MgFe{sub 2}O{sub 4} having a ca. 6 nm crystal size. > This high heat generation ability was ascribed to the increase in hysteresis loss. > Hysteresis loss was increased by the formation of a single domain.

  20. Preparation and properties of plasma-polymerized thiophene (PPT) conducting films

    Energy Technology Data Exchange (ETDEWEB)

    Sadhir, R.K. (Westinghouse Science and Tech. Center, Pittsburgh, PA (United States)); Schoch, K.F. Jr. (Westinghouse Science and Tech. Center, Pittsburgh, PA (United States))

    1993-01-15

    This paper presents, for the first time, conducting films of polythiophene prepared by plasma-polymerization. In this technique, ionized argon is the initiating species for the polymerization of thiophene in a region away from the high RF flux-density. These films displayed a conductivity of 1.8 x 10[sup -4] S cm[sup -1] after doping with iodine. The surface morphology of the films deposited away from the high RF flux-density region showed topology similar to the films prepared by electrochemical methods. The films deposited near the high RF flux-density region showed a platelet structure. (orig.)

  1. Composition, XRD and morphology study of laser prepared LiNbO3 films

    Science.gov (United States)

    Jelínek, M.; Havránek, V.; Remsa, J.; Kocourek, T.; Vincze, A.; Bruncko, J.; Studnička, V.; Rubešová, K.

    2013-03-01

    LiNbO3 films were deposited by PLD from LiNbO3 crystalline or from three different stoichiometric or Li-enriched LiNbO3 targets. Polycrystalline films were prepared on SiO2/Si or sapphire substrates at temperatures T S ˜650-750 °C. Main attention was paid to the influence of targets preparation and the deposition conditions on films composition, morphology and crystallinity. The thin-film morphology was determined by SEM microscopy. The composition was measured by SIMS, RBS, PIXE and PIGE methods. Highly oriented, smooth and stoichiometric LiNbO3 films were synthesized.

  2. Preparation and characterization of collagen/hydroxypropyl methylcellulose (HPMC) blend film.

    Science.gov (United States)

    Ding, Cuicui; Zhang, Min; Li, Guoying

    2015-03-30

    This study aimed to prepare and characterize the collagen/HPMC blend film (1/1). Thermogravimetric analysis and differential scanning calorimetry were used to investigate the thermal properties of the film. Both thermal decomposition temperature and denaturation temperature of the blend film were higher than those of the collagen film due to the intermolecular hydrogen bonding interaction between collagen and HPMC, which was demonstrated by Fourier transform infrared spectroscopy. Additionally, the morphologies, mechanical properties and hydrophilicity of films were examined. The blend film exhibited a more homogeneous and compact structure compared with that of the collagen film, as observed from scanning electron microscopy and atomic force microscopy. The tensile strength, ultimate elongation and hydrophilicity of the blend film were superior to those of the pure collagen film. Furthermore, the introduction of polyethylene glycol 1500 had almost no influence on the thermal properties of the blend film but obviously improved its stretch-ability and smoothness.

  3. Superhydrophilicity-assisted preparation of transparent and visible light activated N-doped titania film.

    Science.gov (United States)

    Xu, Qing Chi; Wellia, Diana V; Amal, Rose; Liao, Dai Wei; Loo, Say Chye Joachim; Tan, Timothy Thatt Yang

    2010-07-01

    A novel and environmental friendly method was developed to prepare transparent, uniform, crack-free and visible light activated nitrogen doped (N-doped) titania thin films without the use of organic Ti precursors and organic solvents. The N-doped titania films were prepared from heating aqueous peroxotitanate thin films deposited uniformly on superhydrophilic uncoated glass substrates. The pure glass substrates were superhydrophilic after being heated at 500 degrees C for 1 h. Nitrogen concentrations in the titania films were adjusted by changing the amount of ammonia solution. The optimal photocatalytic activity of the N-doped titania films was about 14 times higher than that of a commercial self-cleaning glass under the same visible light illumination. The current reported preparative technique is generally applicable for the preparation of other thin films.

  4. Superhydrophilicity-assisted preparation of transparent and visible light activated N-doped titania film

    Science.gov (United States)

    Xu, Qing Chi; Wellia, Diana V.; Amal, Rose; Liao, Dai Wei; Loo, Say Chye Joachim; Tan, Timothy Thatt Yang

    2010-07-01

    A novel and environmental friendly method was developed to prepare transparent, uniform, crack-free and visible light activated nitrogen doped (N-doped) titania thin films without the use of organic Ti precursors and organic solvents. The N-doped titania films were prepared from heating aqueous peroxotitanate thin films deposited uniformly on superhydrophilic uncoated glass substrates. The pure glass substrates were superhydrophilic after being heated at 500 °C for 1 h. Nitrogen concentrations in the titania films were adjusted by changing the amount of ammonia solution. The optimal photocatalytic activity of the N-doped titania films was about 14 times higher than that of a commercial self-cleaning glass under the same visible light illumination. The current reported preparative technique is generally applicable for the preparation of other thin films.

  5. Microwave Measurements of Ferrite Polymer Composite Materials

    Directory of Open Access Journals (Sweden)

    Rastislav Dosoudil

    2004-01-01

    Full Text Available The article focuses on the microwave measurements performed on the nickel-zinc sintered ferrite with the chemical formula Ni0.3Zn0.7Fe2O4 produced by the ceramic technique and composite materials based on this ferrite and a non-magnetic polymer (polyvinyl chloride matrix. The prepared composite samples had the same particle size distribution 0-250um but different ferrite particle concentrations between 23 vol% and 80 vol%. The apparatus for measurement of the signal proportional to the absolute value of scattering parameter S11 (reflexion coefficient is described and the dependence of measured reflected signal on a bias magnetic field has been studied. By means of experiments, the resonances to be connected with the geometry of microwave experimental set-up were distinguished from ferromagnetic resonance arising in ferrite particles of composite structure. The role of local interaction fields of ferrite particles in composite material has been discussed.

  6. HYDROTHERMAL SYNTHESIS OF NANO-METER MICROPOROUS ZINC FERRITE

    Institute of Scientific and Technical Information of China (English)

    Xiaoling Hu; Ping Guan; Xin Yan

    2004-01-01

    Nano-meter microporous zinc ferrite was prepared by a hydrothermal method, using triethylamine as a template. Adsorption curves showed that the product had a microporous structure. The effects of precursor pH, reaction temperature and reaction time on the preparation were studied, yielding optimal conditions: pH=11,448 K, 360 min. The morphology of zinc ferrite as observed by TEM, showed that zinc ferrite was well-crystallized and well-dispersed with little conglomeration.

  7. Preparation of a hydrophobic polythiophene film to improve protein adsorption and proliferation of PC 12 cells.

    Science.gov (United States)

    Li, Da-Feng; Wang, Hua-Jie; Fu, Jian-Xi; Wang, Wei; Jia, Xue-Shun; Wang, Jin-Ye

    2008-12-25

    High quality films of polythiophene with different alkyl side chains were successfully synthesized by a novel method in the presence of sodium dodecylbenzenesulonate (SDBS) under N2 atmosphere on the PTFE (polytetrafluorethylene) substrate. The as-prepared films were characterized by scanning electron microscopy (SEM), conductivity measurement, and water contact angle measurement. The morphologies of the films were homogeneous with micro-/nanostructures, and their conductivities were high enough for biomedical applications. Hydrophobicity of the films could be adjusted easily by inducing alkyl side chains with different length, which could control protein adsorption in succession. Hydrophobic polythiophene film with a long alkyl side chain had a higher ability of protein adsorption and PC 12 cell proliferation. The biocompatibility study of the synthesized films in vitro proved that the synthesized films were not cytotoxic to two cell lines used and could support cell attachment and proliferation well. Polythiophenes films prepared by in-situ deposition will be good candidates for biomedical applications.

  8. Preparation and properties of GaN films on Si(111) substrates

    Institute of Scientific and Technical Information of China (English)

    杨莺歌; 马洪磊; 郝晓涛; 马瑾; 薛成山; 庄惠照

    2003-01-01

    High-quality gallium nitride (GaN) films were prepared on Si(111) substrates by sputtering post-annealing-reaction technique. XRD, XPS, and SEM measurement results indicate that polycrystalline GaN with hexagonal structure was successfully prepared. Intense room- temperature photoluminescence that peaked at 354 nm of the films is observed. The bandgap of these films has a blueshift with respect to bulk GaN.

  9. The preparation, processing and properties of thin and thick films for microelectric applications

    Science.gov (United States)

    Bagley, B. G.; Greene, L. H.; Barboux, P.; Tarascon, J. M.; Venkatesan, T.

    High-Tc thin and thick films of YBa2Cu2O(7-y) and thick films based on the Bi-Sr-Ca-Cu and Tl-Ba-Ca-Cu systems were prepared and their properties investigated. It was found that YB2Cu3O(7-y) thin films prepared at temperatures up to 400 C, have amorphous structures, and those prepared in the 400-650 C region exhibit polyphase microstructure, due to the rapid crystallization kinetics of the competing phases. Methods for bipassing the 'forbidden' temperature region are described. Preparation of YBa2Cu2O(7-y) thick films was achieved via an aqueous sol-gel technique. Bi-Sr-Ca-Cu- and Tl-Ba-Ca-Cu-based thick films were prepared via the decomposition of glycerol-based solutions containing nitrates of the elements.

  10. Characterisation of Pb thin films prepared by the nanosecond pulsed laser deposition technique for photocathode application

    OpenAIRE

    Lorusso, Antonella; Gontad, F.; Broitman, Esteban; Chiadroni, E.; Perrone, Walter

    2015-01-01

    Pb thin films were prepared by the nanosecond pulsed laser deposition technique on Si (100) and polycrystalline Nb substrates for photocathode application. As the photoemission performances of a cathode are strongly affected by its surface characteristics, the Pb films were grown at different substrate temperatures with the aim of modifying the morphology and structure of thin films. An evident morphological modification in the deposited films with the formation of spherical grains at higher ...

  11. Preparation and adsorption properties of nano magnetite chitosan films for heavy metal ions from aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Lasheen, M.R., E-mail: ragaei24@link.net [Water Pollution Research Department, Environmental Research Division, National Research Centre, 33-El Buhoth St., Dokki, Cairo, 12311 (Egypt); El-Sherif, Iman Y., E-mail: iman57us@yahoo.com [Water Pollution Research Department, Environmental Research Division, National Research Centre, 33-El Buhoth St., Dokki, Cairo, 12311 (Egypt); Tawfik, Magda E., E-mail: magdaemileta@yahoo.com [Polymers and Pigments Department, National Research Centre, 33-El Buhoth St., Dokki, Cairo, 12311 (Egypt); El-Wakeel, S.T., E-mail: shaimaa_tw@yahoo.com [Water Pollution Research Department, Environmental Research Division, National Research Centre, 33-El Buhoth St., Dokki, Cairo, 12311 (Egypt); El-Shahat, M.F., E-mail: elshahatmf@hotmail.com [Faculty of Science, Ain Shams University, Khalifa El-Maamon St., Abbasiya Sq., 11566, Cairo (Egypt)

    2016-08-15

    Highlights: • Nano magnetite–chitosan films were prepared by casting method. • The efficiency of the prepared films for removing heavy metals was investigated. • The adsorption mechanism was studied using different isotherm and kinetic models. • Films reuse and metals recovery were studied. - Abstract: Nano magnetite chitosan (NMag–CS) film was prepared and characterized with different analytical methods. X-ray diffraction (XRD) patterns confirmed the formation of a pure magnetite structure and NMag–CS nanocomposite. TEM image of the film, revealed the uniform dispersion of magnetite nanoparticles inside chitosan matrix. The adsorption properties of the prepared film for copper, lead, cadmium, chromium and nickel metal ions were evaluated. Different factors affecting the uptake behavior by the composite films such as time, initial pH and film dose were investigated. The adsorption equilibrium attained using 2 g/L of the film after 120 min of reaction. The equilibrium data were analyzed using Langmuir and Freundlich models. The adsorption kinetics followed the mechanism of the pseudo-second-order equation for all metals. The metals regenerated from films with an efficiency greater than 95% using 0.1 M ethylene diamine tetra acetic acid (EDTA) and films were successfully reused for adsorption.

  12. Preparation and Photocatalytic Activity of ZnS/Nickel-Zinc Ferrite Magnetic Photocatalyst%ZnS/镍锌铁氧体磁性光催化剂的制备与光催化活性

    Institute of Scientific and Technical Information of China (English)

    李燕; 徐海燕; 徐玲; 项磊

    2011-01-01

    Nickel-zinc ferrite powders prepared by coprecipitation method were modified by NH3 · H20 and EDTA, respectively. Then ZnS/nickel-zinc ferrite composite powders were prepared by the sonochemical method using zinc acetate, thioacetamide and modified nickel-zinc ferrite as raw materials. The as-prepared sample was characterized by X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM) and energy dispersive spectroscopy (EDS). The photocatalytic activity ofthe sample was evaluated by degradation of methyl orange under sunlight. The results show that the ZnS coating nickel-zinc ferrite is cubic sphalerite structure and a single ZnS particle size is between 15 -25 nm. ZnS/nickel-zinc ferrite powders have photocatalytic activity under the irradiation of visible light, the ZnS/nickel-zinc ferrite powders still have magnetic property, and can be separated from the system by applying magnetic field.%采用共沉淀法制备了镍锌铁氧体,并用氨水、乙二胺四乙酸进行表面改性;然后以醋酸锌、硫代乙酰胺和表面改性的镍锌铁氧体为原料,采用超声化学法制备了ZnS/镍锌铁氧体的复合粉体.采用X射线粉末衍射(XRD),高分辨透射电子显微镜(HRTEM)以及所带能谱仪(EDS)对所制得的样品进行了表征,并以太阳光为光源,甲基橙为目标降解物,对其光催化活性进行了研究.结果表明:镍锌铁氧体负载的ZnS为立方闪锌矿结构,单个ZnS颗粒尺寸分布在15 ~25 nm之间;ZnS/镍锌铁氧体复合粉体在可见光下具有一定的光催化活性,且具有磁性能可实现磁分离回收.

  13. Preparation of mesoporous silica thin films by photocalcination method and their adsorption abilities for various proteins.

    Science.gov (United States)

    Kato, Katsuya; Nakamura, Hitomi; Yamauchi, Yoshihiro; Nakanishi, Kazuma; Tomita, Masahiro

    2014-07-01

    Mesoporous silica (MPS) thin film biosensor platforms were established. MPS thin films were prepared from tetraethoxysilane (TEOS) via using sol-gel and spin-coating methods using a poly-(ethylene oxide)-block-poly-(propylene oxide)-block-poly-(ethylene oxide) triblock polymer, such as P123 ((EO)20(PO)70(EO)20) or F127 ((EO)106(PO)70(EO)106), as the structure-directing agent. The MPS thin film prepared using P123 as the mesoporous template and treated via vacuum ultraviolet (VUV) irradiation to remove the triblock copolymer had a more uniform pore array than that of the corresponding film prepared via thermal treatment. Protein adsorption and enzyme-linked immunosorbent assay (ELISA) on the synthesized MPS thin films were also investigated. VUV-irradiated MPS thin films adsorbed a smaller quantity of protein A than the thermally treated films; however, the human immunoglobulin G (IgG) binding efficiency was higher on the former. In addition, protein A-IgG specific binding on MPS thin films was achieved without using a blocking reagent; i.e., nonspecific adsorption was inhibited by the uniform pore arrays of the films. Furthermore, VUV-irradiated MPS thin films exhibited high sensitivity for ELISA testing, and cytochrome c adsorbed on the MPS thin films exhibited high catalytic activity and recyclability. These results suggest that MPS thin films are attractive platforms for the development of novel biosensors.

  14. Optical and magnetic properties of monophasic cadmium ferrite (CdFe{sub 2}O{sub 4}) nanostructure prepared by thermal treatment method

    Energy Technology Data Exchange (ETDEWEB)

    Naseri, Mahmoud, E-mail: mahmoud.naseri55@gmail.com

    2015-10-15

    This paper reports optical and magnetic properties of CdFe{sub 2}O{sub 4} nanostructure which was prepared by a simple thermal treatment method. Calcination was conducted at temperatures between 673 and 773 K, and final products had different crystallite sizes ranging from 47 to 138 nm. The influence of calcination temperature on the degree of crystallinity, microstructure, and phase composition was investigated by different characterization techniques, i.e., X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), and Fourier transform infrared spectroscopy (FT-IR), respectively. The compositions of the samples were determined by Energy dispersive X-ray analysis (EDXA). The effect of calcination temperature on band gap energy was studied by UV–vis absorption spectra. The formed nanostructures exhibited ferromagnetic behaviors with unpaired electrons spins, which was confirmed by using vibrating sample magnetometer (VSM) and electron paramagnetic resonance (EPR) spectroscopy. - Highlights: • Metal nitrates were added into an aqueous solution of PVA and the mixed solution was heated at 373 K. • The effect of calcination temperature on morphology of cadmium ferrite nanostructures was characterized. • Elemental composition, phase composition and others properties were investigated.

  15. Magnetic, ferroelectric and leakage current properties of gadolinium doped bismuth ferrite thin films by sol-gel method

    Science.gov (United States)

    Chen, Hone-Zern; Kao, Ming-Cheng; Young, San-Lin; Hwang, Jun-Dar; Chiang, Jung-Lung; Chen, Po-Yen

    2015-05-01

    Bi0.9Gd0.1FeO3 (BGFO) thin films were fabricated on Pt(111)/Ti/SiO2/Si(100) substrates by using the sol-gel technology. The effects of annealing temperature (400-700 °C) on microstructure and multiferroic properties of thin films were investigated. The X-ray diffraction analysis showed that the BGFO thin films had an orthorhombic structure. The thin films showed ferroelectric and ferromagnetic properties with remanent polarization (2Pr) of 10 μC/cm2, remnant magnetization (2Mr) of 2.4 emu/g and saturation magnetization (Ms) of 5.3 emu/g. A small leakage current density (J) was 4.64×10-8 A/cm2 under applied field 100 kV/cm. It was found that more than one conduction mechanism is involved in the electric field range used in these experiments. The leakage current mechanisms were controlled by Poole-Frenkel emission in the low electric field region and by Schottky emission from the Pt electrode in the high field region.

  16. Effect of chromium substitution on the dielectric properties of mixed Ni-Zn ferrite prepared by WOWS sol–gel technique

    Energy Technology Data Exchange (ETDEWEB)

    Ashtar, M. [Nano Scale Physics Laboratory, Department of Physics, Air University, PAF Complex E-9, Islamabad (Pakistan); Munir, A.; Anis-ur-Rehman, M. [Applied Thermal Physics Laboratory, Department of Physics, COMSATS Institute of Information Technology, Islamabad 44000 (Pakistan); Maqsood, A., E-mail: tpl.qau@usa.net [Nano Scale Physics Laboratory, Department of Physics, Air University, PAF Complex E-9, Islamabad (Pakistan)

    2016-07-15

    Graphical abstract: Variation of AC conductivity (σ{sub AC}) as a function of natural log of angular frequency (lnω) for Ni{sub 0.5}Zn{sub 0.5}Fe{sub 2-x}Cr{sub x}O{sub 4} nanoferrites at room temperature. - Highlights: • Cr doped mixed Ni-Zn ferrites were successfully synthesized by a newly developed WOWS sol gel technique. • The specific surface area and specific surface area to volume ratio increased with decrease in particle size. • The resonance peaks appeared in dielectric loss graphs, shifting towards low frequency with the increase in Cr concentration. • The prepared samples have the lowest values of the dielectric constant. • The dielectric constant were observed to be inversely proportional to square root of the AC resistivity. - Abstract: Cr{sup +3} doped Ni-Zn nanoferrite samples with composition Ni{sub 0.5}Zn{sub 0.5}Fe{sub 2-x}Cr{sub x}O{sub 4}(x = 0.1, 0.2, 0.3, 0.4) were synthesized With Out Water and Surfactant (WOWS) sol-gel technique. The structural, morphological and dielectric properties of the samples were investigated. The lattice constant, crystallite size, theoretical density and porosity of each sample were obtained from X-ray diffraction (XRD) data. The specific surface area and specific surface area to volume ratio increased with the decrease in the size of Cr{sup +3} doped Ni-Zn ferrite nanoparticles, as the concentration of Cr{sup +3} increased. The SEM analysis revealed that the particles were of nano size and of spherical shape. The dielectric parameters such as dielectric constant (ε′) and dielectric loss (tanδ) of all the samples as a function of frequency at room temperature were measured. The AC conductivity (σ{sub AC}) was determined from the dielectric parameters, which showed increasing trend with the rise in frequency.

  17. Preparation and Characterization of Keratin Blended Films using Biopolymers for Drug Controlled Release Application

    Directory of Open Access Journals (Sweden)

    Ansaya Thonpho

    2016-08-01

    Full Text Available Keratin solution was separately blended with collagen, gelatin, sericin and starch for films preparation. All the blended films had smooth surfaces without phase separation, except the keratin/starch blend film. The native keratin film showed small particles embedded in all the film surfaces that resulted in them being rough. The structure of the native keratin film changed from beta-sheet to random coil at high blend ratio of other substances. This result increased the dissolution of the films especially the keratin/starch blend. The results relate directly to the decreased thermal stability of this film. However, the changes in structure did not affect the chlorhexidine release pattern. It is possible that the interaction between the drug and blending substances, and the substances to water molecules are the main factor influencing the drug release pattern from the films.

  18. Preparation and Properties of Silver Nanowire-Based Transparent Conductive Composite Films

    Science.gov (United States)

    Tian, Ji-Li; Zhang, Hua-Yu; Wang, Hai-Jun

    2016-06-01

    Silver nanowire-based transparent conductive composite films with different structures were successfully prepared using various methods, including liquid polyol, magnetron sputtering and spin coating. The experimental results revealed that the optical transmittance of all different structural composite films decreased slightly (1-3%) compared to pure films. However, the electrical conductivity of all composite films had a great improvement. Under the condition that the optical transmittance was greater than 78% over the wavelength range of 400-800 nm, the AgNW/PVA/AgNW film became a conductor, while the AZO/AgNW/AZO film and the ITO/AgNW/ITO film showed 88.9% and 94% reductions, respectively, for the sheet resistance compared with pure films. In addition, applying a suitable mechanical pressure can improve the conductivity of AgNW-based composite films.

  19. Gas Sensitivity of Poly (3, 4-ethylene dioxythiophene) Prepared by a Modified LB Film Method

    Institute of Scientific and Technical Information of China (English)

    ZHENG Huajing; JIANG Yadong; XU Jianhua; YANG Yajie

    2011-01-01

    An arachidic acid/poly (3, 4-ethylene dioxythiophene) (AA/PEDOT) multilayer Langmuir-Blodgett (LB) film was prepared by a modified LB film method. The theories were utilized to explain the effects between HCl molecule and LB film. The gas sensitivity mechanism of poly (3,4-ethylene dioxythiophene) (PEDOT) muitilayer film can be explained by the charge transfer between p system of PEDOT and oxidization HCl system. The gas sensitivity of PEDOT LB film deposited interdigital electrode to HCl was tested. The results showed that film thickness, treating temperature,deposition speed had different influence on film gas sensitivity. The AA/PEDOT film deposited device exhibited nonlinear behavior to HCl gas at lower concentration (20-60 ppm) and linear response behavior at higher gas concentration was observed. The time of the compound LB film of the AA/PEDOT responding to the 30 ppm HCl gas is about 20 seconds, which is far quicker than the time of the film to the PEDOT- PRESS film(about 80 seconds). It is not higher film press to better film. When the film press attains 45 mNs/m, the sensitivity of the AA/PEDOT film on the contrary descends.

  20. Structural and Optoelectrical Properties of ZnTe Thin Films Prepared by E-Beam Evaporation

    Science.gov (United States)

    Zia, Rehana; Saleemi, Farhat; Riaz, Madeeha; Nassem, Shahzad

    2016-10-01

    ZnTe thin films have been prepared by an electron-beam evaporation technique on glass substrates, changing the accelerating voltage and the substrate temperature at accelerating voltage of 2 kV. Structural analysis showed that all the films had cubic structure with preferential orientation along (111) direction, though (220) and (311) orientations were also present. The (111) peak intensity increased with increasing film thickness. The crystallite size increased with increasing film thickness. Conductivity measurements showed that the films were p-type. Films prepared at accelerating voltage of 2 kV exhibited minimum resistivity. Optical characterization indicated that both absorbing and transparent thin films can be achieved by using different deposition conditions. The optical bandgap value was found to vary with substrate temperature.

  1. Preparation and Characterization of Nano-Structured SiO2 Thin Films on Carbon Steel

    Institute of Scientific and Technical Information of China (English)

    Rong Chun XIONG; Dong Zhou YAN; Gang WEI

    2003-01-01

    Nano-structured SiO2 thin films were prepared on the surface of carbon steel for the first time by LPD. The compositions of the films were analyzed by XPS, and the surface morphology of the thin films were observed by AFM. The thin films were constituted by compact particles of SiO2, and there was no Fe in the films. In the process of film forming, the SiO2 colloid particles were deposited or absorbed directly onto the surface of carbon steel substrates that were activated by acid solution containing inhibitor, and corrosion of the substrates was avoided. The nano-structured SiO2 thin films that were prepared had excellent protective efficiency to the carbon steel.

  2. Heat generation ability in AC magnetic field of nano MgFe2O4-based ferrite powder prepared by bead milling

    Science.gov (United States)

    Hirazawa, Hideyuki; Aono, Hiromichi; Naohara, Takashi; Maehara, Tsunehiro; Sato, Mitsunori; Watanabe, Yuji

    2011-03-01

    Nanosized MgFe2O4-based ferrite powder having heat generation ability in an AC magnetic field was prepared by bead milling and studied for thermal coagulation therapy applications. The crystal size and the particle size significantly decreased by bead milling. The heat generation ability in an AC magnetic field improved with the milling time, i.e. a decrease in crystal size. However, the heat generation ability decreased for excessively milled samples with crystal sizes of less than 5.5 nm. The highest heat ability (ΔT=34 °C) in the AC magnetic field (370 kHz, 1.77 kA/m) was obtained for fine MgFe2O4 powder having a ca. 6 nm crystal size (the samples were milled for 6-8 h using 0.1 mm ϕ beads). The heat generation of the samples was closely related to hysteresis loss, a B-H magnetic property. The reason for the high heat generation properties of the samples milled for 6-8 h using 0.1 mm ϕ beads was ascribed to the increase in hysteresis loss by the formation of a single domain. Moreover, the improvement in heating ability was obtained by calcination of the bead-milled sample at low temperature. In this case, the maximum heat generation (ΔT=41 °C) ability was obtained for a ca. 11 nm crystal size sample was prepared by crystal growth during the sample calcination. On the other hand, the ΔT value for Mg0.5Ca0.5Fe2O4 was synthesized using a reverse precipitation method decreased by bead milling.

  3. Surface properties of latex film and solvent-borne film resulted from fluorinated acrylate copolymers prepared by emulsion polymerization

    Directory of Open Access Journals (Sweden)

    2007-01-01

    Full Text Available The fluorinated acrylate copolymer, poly (BMA-co-DFHMA, was prepared by emulsion polymerization using a preemulsified monomer addition process. The FTIR and 1H –NMR were used to characterize the copolymer structure. The contact angle of water on the solvent-borne film increased dramatically and reached an equilibrium value (103° when the PDFHMA content in the copolymer was only 0.97 mol%. However, the contact of water on the latex film increased slowly, and reached the equilibrium value of 99° until the fluorinated component content was as highly as 9 mol%. A similar result was observed for the oil contact angle on the two types of films. XPS results showed that when the F/C ratio on film surfaces reached equilibrium, the required content of fluorinated component in the copolymer for the solvent-borne film was much lower than that for the latex film.

  4. Photoactive composite films prepared from mixtures of polystyrene microgel dispersions and poly(3-hexylthiophene) solutions.

    Science.gov (United States)

    Chen, Mu; Cui, Zhengxing; Edmondson, Steve; Hodson, Nigel; Zhou, Mi; Yan, Junfeng; O'Brien, Paul; Saunders, Brian R

    2015-11-14

    Whilst polystyrene microgels belong to the oldest family of microgel particles, their behaviours when deposited onto substrates or prepared as composites have received little attention. Because polystyrene microgels are solvent-swellable, and inherently colloidally stable, they are well suited to form composites with conjugated polymers. Here, we investigate the morphology and light absorption properties of spin coated composite films prepared from mixed dispersions of polystyrene microgels and poly(3-hexylthiophene) (P3HT) for the first time. We compare the morphologies of the composite films to spin coated microgel films. The films were studied using optical microscopy, SEM, AFM, wide-angle X-ray diffraction and UV-visible spectroscopy. The films contained flattened microgel particles with an aspect ratio of ∼10. Microgel islands containing hexagonally close packed particles were evident for both the pure microgel and microgel/P3HT composite films. The latter were electrically conducting. The composite film morphology was dependent on the microgel and P3HT concentration used for film preparation and a morphology phase diagram was constructed. The P3HT phase acted as an electrically conducting cement and increased the robustness of the films to solvent washing. The composite films were photoactive due to the P3HT component. The absorbance for the films was tuneable and increased linearly with both microgel and P3HT concentration. The results of the study should apply to other organic swellable microgel/conjugated polymer combinations and may lead to new colloidal composites for future optoelectronic applications.

  5. Plasma sintering of ferritic steel reinforced with niobium carbide prepared by high energy milling; Sinterizacao a plasma de aco ferritico reforcado com carbeto de niobio preparado por moagem de alta energia

    Energy Technology Data Exchange (ETDEWEB)

    Silva Junior, J.F. da; Almeida, E.O.; Gomes, U.U.; Alves Junior, C.; Messias, A.P. [Universidade Federal do Rio Grande do Norte (UFRN), Natal (Brazil). Lab. de Materiais Ceramicos e Metais Especiais; Universidade Federal do Rio Grande do Norte (UFRN), Natal (Brazil). Lab. de Processamento de Materiais por Plasma

    2010-07-01

    Plasma is an ionized gas where ions are accelerated from anode to cathode surface, where the sample is placed. There are a lot of collisions on cathode surface by ions heating and sintering the sample. High energy milling (HEM) is often used to produce composite particles to be used on powder metallurgy. These particles can exhibit fine particles and high phase dispersion. This present work aim to study ferritic steels reinforced with 3%NbC prepared by HEM and sintered on plasma furnace. Ferritic steel and NbC powders were milled during 5 hours and characterized by SEM, XRD and laser scattering. Then, these composite powders were compacted in a cylindrical steel die and then sintered in a plasma furnace. Vickers microhardness tests and SEM and XRD analysis were performed on sintered samples. (author)

  6. Preparation of cuxinygazsen precursor films and powders by electroless deposition

    Science.gov (United States)

    Bhattacharya, Raghu N.; Batchelor, Wendi Kay; Wiesner, Holm; Ramanathan, Kannan; Noufi, Rommel

    1999-01-01

    A method for electroless deposition of Cu.sub.x In.sub.y Ga.sub.z Se.sub.n (x=0-2, y=0-2, z=0-2, n=0-3) precursor films and powders onto a metallic substrate comprising: preparing an aqueous bath solution of compounds selected from the group consisting of: I) a copper compound, a selenium compound, an indium compound and gallium compound; II) a copper compound, a selenium compound and an indium compound; III) a selenium compound, and indium compound and a gallium compound; IV) a selenium compound and a indium compound; and V) a copper compound and selenium compound; each compound being present in sufficient quantity to react with each other to produce Cu.sub.x In.sub.y Ga.sub.z Se.sub.n (x=0-2, y=0-2, z=0-2, n=0-3); adjusting the pH of the aqueous bath solution to an acidic value by the addition of a dilute acid; and initiating an electroless reaction with an oxidizing counterelectrode for a sufficient time to cause a deposit of Cu.sub.x In.sub.y Ga.sub.z Se.sub.n (x=0-2, y=0-2, z=0-2, n=0-3) from the aqueous bath solution onto a metallic substrate.

  7. Photocatalytic activity of porous TiO2 films prepared by anodic oxidation

    Institute of Scientific and Technical Information of China (English)

    WANG Wei; TAO Jie; WANG Tao; WANG Ling

    2007-01-01

    Anatase titanium dioxide is an active photocatalyst, however, it is difficult to be immobilized on the substrate.The crystalline TiO2 porous film was prepared directly on the surface of pure titanium by anodic oxidation. The film was then used for photocatalysis via the methyl orange degradation method. The effects of anodization voltage, pH value, TiO2 film area and degradation time on the photocatalyst were investigated respectively by UV-visible spectrum. It was indicated that the TiO2 film prepared by anodic oxidation at 140 V had the best photocatalysis capability and the degradation of methyl orange was accelerated with acid addition.

  8. Preparation of silica thin films by novel wet process and study of their optical properties.

    Science.gov (United States)

    Im, Sang-Hyeok; Kim, Nam-Jin; Kim, Dong-Hwan; Hwang, Cha-Won; Yoon, Duck-Ki; Ryu, Bong-Ki

    2012-02-01

    Silicon dioxide (SiO2) thin films have gained considerable attention because of their various industrial applications. For example, SiO2 thin films are used in superhydrophilic self-cleaning surface glass, UV protection films, anti-reflection coatings, and insulating materials. Recently, many processes such as vacuum evaporation, sputtering, chemical vapor deposition, and spin coating have been widely applied to prepare thin films of functionally graded materials. However, these processes suffer from several engineering problems. For example, a special apparatus is required for the deposition of films, and conventional wet processes are not suitable for coating the surfaces of substrates with a large surface area and complex morphology. In this study, we investigated the film morphology and optical properties of SiO2 films prepared by a novel technique, namely, liquid phase deposition (LPD). Images of the SiO2 films were obtained by scanning electron microscopy (SEM) and atomic force microscopy (AFM) in order to study the surface morphology of these films: these images indicate that films deposited with different reaction times were uniform and dense and were composed of pure silica. Optical properties such as refractive index and transmittance were estimated by UV-vis spectroscopy and ellipsometry. SiO2 films with porous structures at the nanometer scale (100-250 nm) were successfully produced by LPD. The deposited film had excellent transmittance in the visible wavelength region.

  9. Preparation of mesoporous silica thin films by photocalcination method and their adsorption abilities for various proteins

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Katsuya, E-mail: katsuya-kato@aist.go.jp [National Institute of Advanced Industrial Science and Technology (AIST), 2266-98 Anagahora, Shimoshidami, Moriyama-ku, Nagoya 463-8560 (Japan); Nakamura, Hitomi [National Institute of Advanced Industrial Science and Technology (AIST), 2266-98 Anagahora, Shimoshidami, Moriyama-ku, Nagoya 463-8560 (Japan); Yamauchi, Yoshihiro; Nakanishi, Kazuma; Tomita, Masahiro [Department of Chemistry for Materials, Graduate School of Engineering, Mie University, 1577 Kurimamachiya-cho, Tsu, Mie 514-8570 (Japan)

    2014-07-01

    Mesoporous silica (MPS) thin film biosensor platforms were established. MPS thin films were prepared from tetraethoxysilane (TEOS) via using sol–gel and spin-coating methods using a poly-(ethylene oxide)-block-poly-(propylene oxide)-block-poly-(ethylene oxide) triblock polymer, such as P123 ((EO){sub 20}(PO){sub 70}(EO){sub 20}) or F127 ((EO){sub 106}(PO){sub 70}(EO){sub 106}), as the structure-directing agent. The MPS thin film prepared using P123 as the mesoporous template and treated via vacuum ultraviolet (VUV) irradiation to remove the triblock copolymer had a more uniform pore array than that of the corresponding film prepared via thermal treatment. Protein adsorption and enzyme-linked immunosorbent assay (ELISA) on the synthesized MPS thin films were also investigated. VUV-irradiated MPS thin films adsorbed a smaller quantity of protein A than the thermally treated films; however, the human immunoglobulin G (IgG) binding efficiency was higher on the former. In addition, protein A–IgG specific binding on MPS thin films was achieved without using a blocking reagent; i.e., nonspecific adsorption was inhibited by the uniform pore arrays of the films. Furthermore, VUV-irradiated MPS thin films exhibited high sensitivity for ELISA testing, and cytochrome c adsorbed on the MPS thin films exhibited high catalytic activity and recyclability. These results suggest that MPS thin films are attractive platforms for the development of novel biosensors. - Highlights: • VUV-treated MPS thin films with removed polymer had uniform pore. • VUV-treated MPS thin films exhibited high sensitivity by ELISA. • Cytochrome c showed the catalytic activity and recyclability on synthesized films.

  10. CEMS study on diluted magneto titanium oxide films prepared by pulsed laser deposition

    Science.gov (United States)

    Nomura, K.; Inaba, K.; Iio, S.; Hitosugi, T.; Hasegawa, T.; Hirose, Y.; Homonnay, Z.

    6% 57Fe doped titanium oxide films, prepared by pulsed laser deposition (PLD) on sapphire substrate at 650° under various vacuum conditions, were characterized mainly by conversion electron Mössbauer spectrometry (CEMS). Two magnetic sextets with hyperfine fields 33 and 29 T, and one doublet were observed in the CEMS spectra of Ti02 films prepared under P02=10-6 and 10-8 torr, which showed ferromagnetism at room temperature, whereas only the doublet of paramagnetic Fe3+ species was observed for the film prepared under P02=10-1 torr.

  11. Preparation and structural properties of thin carbon films by very-high-frequency magnetron sputtering

    Institute of Scientific and Technical Information of China (English)

    高明伟; 叶超; 王响英; 何一松; 郭佳敏; 杨培芳

    2016-01-01

    Growth and structural properties of thin a-C films prepared by the 60 MHz very-high-frequency (VHF) magnetron sputtering were investigated. The energy and flux of ions impinging the substrate were also analyzed. It is found that the thin a-C films prepared by the 60 MHz sputtering have a lower growth rate, a smooth surface, and more sp3 contents. These features are related to the higher ion energy and the lower ions flux onto the substrate. Therefore, the 60 MHz VHF sputtering is more suitable for the preparation of thin a-C film with more sp3 contents.

  12. Preparation and Characterization of HPMC/PVP Blend Films Plasticized with Sorbitol

    Directory of Open Access Journals (Sweden)

    H. Somashekarappa

    2013-01-01

    Full Text Available The aim of this present work is to investigate the effect of plasticizers like Sorbitol on microstructural and mechanical properties of hydroxypropyl methylcellulose (HPMC and Polyvinylpyrrolidone (PVP blend films. The pure blend and plasticized blend films were prepared by solution casting method and investigated using wide angle X-ray scattering (WAXS method. WAXS analysis confirms that the plasticizers can enter into macromolecular blend structure and destroy the crystallinity of the films. FTIR spectra show that there are a shift and decrease in the intensity of the peaks confirming the interaction of plasticizer with the blend. Mechanical properties like tensile strength and Young’s Modulus decrease up to 0.6% of Sorbitol content in the films. Percentage of elongation at break increases suggesting that the plasticized films are more flexible than pure blend films. These films are suitable to be used as environmental friendly and biodegradable packaging films.

  13. Preparation and gas sensing properties of novel CdS-supramolecular organogel hybrid films

    Science.gov (United States)

    Xia, Huiyun; Peng, Junxia; Liu, Kaiqiang; Li, Chen; Fang, Yu

    2008-05-01

    A novel CdS-supramolecular organogel hybrid film with unusual morphology has been fabricated by exposing a supramolecular organogel film containing Cd(Ac)2 in an H2S atmosphere at room temperature. The organogel film was prepared by spin-coating a LMOG (low-molecular weight organic gelator) gel of dmethyl sulfoxide onto a glass plate substrate. XRD, SEM, EDS, TG-DTA, UV-vis, PL (photoluminescence) spectroscopy and PL lifetime measurements were employed to characterize the film. It was shown that the organogel film had functioned as a template to control the morphology of the final hybrid film. The quantities and sizes of the CdS particles embedded in the organogel films can be easily altered by varying the initial concentration of Cd(Ac)2. Importantly, the PL of the hybrid film is sensitive to the presence of some volatile organic monoamines and diamines. The selectivity and reversibility of the sensing process were investigated.

  14. Optical properties and residual stress in Nb-Si composite films prepared by magnetron cosputtering.

    Science.gov (United States)

    Tang, Chien-Jen; Porter, Glen Andrew; Jaing, Cheng-Chung; Tsai, Fang-Ming

    2015-02-01

    This paper investigates Nb-Si metal composite films with various proportions of niobium in comparison to pure Nb films. Films were prepared by two-target RF-DC magnetron cosputtering deposition. The optical properties and residual stress were analyzed. A composition of Nb(0.74)Si(0.26) was chosen toward the design and fabrication of solar absorbing coatings having a high absorption in a broad wavelength range, a low residual stress, and suitable optical constants. The layer thicknesses and absorption characteristics of the Nb-Si composite films adhere more closely to the design than other coatings made of dielectric film materials.

  15. Tribological Properties of DLC Film Prepared by C + Ion Beam-assisted Deposition (IBAD)

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    C + ion beam-assisted deposition was utilized to prepare deposit diamond-like carbon (DLC) film.With the help of a series of experiments such as Raman spectroscopy, FT- IR spectroscopy, AFM and nanoindentation, the DLC film has been recognized as hydrogenated DLC film and its tribological properties have been evaluated.The ball-on-disc testing results show that the hardness and the tribological properties of the DLC film produced by C + ion beam-assisted deposition are improved significandy.DLC film produced by C+ ion beam-assisted deposition is positive to have a prosperous tribological application in the near future.

  16. Preparation and Photocatalytic Property of Porous TiO2 Film with Net-like Framework

    Institute of Scientific and Technical Information of China (English)

    XU Rong-guo; YAO Jian-xi; LAI Xiao-yong; MAO Dan; XING Chao-jian; WANG Dan

    2009-01-01

    By the UV-curing method, a porous TiO2 film with net-like framework has been prepared. The characte-rization results of the porous TiO2 film by means of SEM, TEM, XRD, and N2 adsorption-desorption analysis show that the net-like framework of the porous TiO2 film is composed of TiO2 nanoparticles, forming three dimensional porous structure. The porous TiO2 film exhibits higher photocatalytic activity for the degradation of methylene blue(MB) dye compared with the conventional dense TiO2 film.

  17. Influence of process parameters on the preparation of pharmaceutical films by electrostatic powder deposition.

    Science.gov (United States)

    Prasad, Leena Kumari; LaFountaine, Justin S; Keen, Justin M; Williams, Robert O; McGinity, James W

    2016-12-30

    Electrostatic powder deposition (ESPD) has been developed as a solvent-free method to prepare pharmaceutical films. The aim of this work was to investigate the influence of process parameters during (1) electrostatic powder deposition, (2) curing, and (3) removal of the film from the substrate on the properties of the film. Polyethylene oxide (PEO) was used as the model polymer and stainless steel 316 as the substrate. Deposition efficiency (i.e. deposited weight) was measured with varying charging voltage, gun tip to substrate distance, and environmental humidity. Scanning electron microscopy was utilized to assess film formation, and adhesive and mechanical strength of films were measured with varying cure temperature and time. Adhesive strength was measured for films prepared on substrates of varying surface roughness. When deposition was performed at low humidity conditions, 25%RH, process parameters did not significantly affect deposition behavior. At 40%RH, increasing deposition efficiency with decreasing gun tip to substrate distance and increasing voltage (up to 60kV) was observed. Complete film formation was seen by 30min at 80°C, compared to lower curing temperatures and times. All films were readily removed from the substrates. The results show the ESPD process can be modified to produce films with good mechanical properties (e.g. tensile strength>0.06MPa), suggesting it is a promising dry powder process for preparing pharmaceutical films.

  18. Effect of humidity on microstructure and properties of YBCO film prepared by TFA-MOD method

    Institute of Scientific and Technical Information of China (English)

    WANG Lianhong; LI Tao; GU Hongwei

    2009-01-01

    Epitaxial YBCO superconducting films were deposited on the single crystal LaAlO3. (001) substrate by metal organic deposition method. All YBCO films were fired at 820 ℃ in humidity range of 2.6%-19.7% atmosphere. Microstructure of YBCO thin films was ana-lyzed by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM). Superconducting properties of YBCO films were measured by four-probe method. XRD results showed that the second phase (such as BaF2)and a-axis-oriented grains existed in the films prepared at 2.6% humidity condition; a-axis-oriented grains increased in the film prepared at higher than 4.2% humidity condition; almost pure c-axias-oriented grains existed in the films fired at 4.2% humidity condition. Morphologies of the YBCO films showed that all films had a smooth and crack-free surface. YBCO film prepared at 4.2% humidity condition showed Jc value of 3.3 MA/cm2 at 77 K in self-field.

  19. Characterization of AZO and Ag based films prepared by RF magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Miao, Dagang [Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hong Kong (China); Jiang, Shouxiang, E-mail: kinor.j@polyu.edu.hk [Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hong Kong (China); Zhao, Hongmei [Department of Prosthodontics, The Affiliated Hospital of Qingdao University, Qingdao (China); Shang, Songmin; Chen, Zhuoming [Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hong Kong (China)

    2014-12-15

    Highlights: • Highly infrared reflective AZO and Ag based films were prepared. • Ag showed better crystallization on AZO film than on glass substrate. • Infrared reflection rate was inversely proportional to the film sheet resistance. • Film with infrared reflection of 97% in FIR region was acquired. - Abstract: Ag, AZO/Ag, Ag/AZO and AZO/Ag/AZO films were prepared on glass substrates by radio frequency (RF) magnetron sputtering technology. The prepared films were systematically investigated by X-ray Diffraction (XRD), Atomic Force Microscopy (AFM), UV–visible spectrophotometer, a four-point probe system and Fourier Transform Infrared Spectroscopy. The results indicated that Ag inner layer starts forming a continuous film at the thickness of 10 nm and Ag layer presents superior crystallization on AZO substrate than that on glass substrate. The continuous Ag inner layer film provided the highest average visible transmittance of 85.4% (AZO/Ag/AZO). The lowest sheet resistance of 3.21 Ω/sq and the highest infrared reflection rate of 97% in FIR region can be obtained on AZO/Ag (15 nm)/AZO film. The high infrared reflection property of the AZO/Ag/AZO coating makes it a promising candidate for solar control films.

  20. Reactively sputtered titanium carbide thin films: Preparation and properties

    Science.gov (United States)

    Eizenberg, M.; Murarka, S. P.

    1983-06-01

    The low resistivity and refractory nature of titanium carbide makes it potentially useful as a diffusion barrier in thin film metallization schemes. In the present investigation, deposition and properties of thin titanium carbide films have been investigated. The films were deposited by reactive radio frequency sputtering in methane-argon mixtures on a variety of substrates. The effects of methane to argon ratio, total sputtering pressure, and power on the film deposition rate, composition and properties were determined. There were interactive effects of these parameters on the composition and properties of these films. Resistivity increased with carbon content; for Ti/C≥1 it was ˜200 μΩ cm. Stress that was compressive was maximum in the nearly stoichiometric TiC film. Grain size was small in all films, especially so in carbon rich films. All stoichiometric titanium carbide films were resistant to HF solutions. Films with TiC/≥1 dissolved easily in ethylene dinitrilo tetra acetric acid (EDTA) solution.

  1. Continuous Preparation of Copper/Carbon Nanotube Composite Films and Application in Solar Cells.

    Science.gov (United States)

    Luo, Xiao Gang; Le Wu, Min; Wang, Xiao Xia; Zhong, Xin Hua; Zhao, Ke; Wang, Jian Nong

    2016-02-08

    Realizing the continuous and large scale preparation of particle/carbon nanotube (CNT) composites with enhanced functionalities, and broad applications in energy conversion, harvesting, and storage systems, remains as a big challenge. Here, we report a scalable strategy to continuously prepare particle/CNT composite films in which particles are confined by CNT films. This is achieved by the continuous condensation and deposition of a cylindrical assembly of CNTs on a paper strip and the in situ incorporation of particles during the layer-by-layer deposition process. A Cu/CNT composite film is prepared as an example; such a film exhibits very high power conversion efficiency when it is used as a counter electrode in a solar cell, compared with previous materials under otherwise identical conditions. The proposed method can be extended to other CNT-based composite films with excellent functionalities for wide applications.

  2. Preparation and characterization of silk fibroin/HPMC blend film

    Energy Technology Data Exchange (ETDEWEB)

    Shetty, G. Rajesha [Department of Physics, Govt. First Grade College Hiriadka, Udupi - 576113 (India); Kumar, R. Madhu; Rao, B. Lakshmeesha; Asha, S.; Sangappa, E-mail: syhalabhavi@yahoo.co.in [Department of Studies in Physics, Mangalore University, Mangalagangotri, Mangalore - 574199 (India)

    2015-06-24

    In this work, the structural and mechanical stability of silk fibroin/Hydroxypropylmethyl cellulose (SF-HPMC) blend films were characterized by X-ray diffraction (XRD) and Universal Testing Machine (UTM). The results indicate that with the introduction of HPMC, the interactions between SF and HPMC results in improved crystallite size and increase in mechanical properties. The blend film obtained is more flexible compared to pure SF film.

  3. Synthesis and Structure of PEDOT Prepared through a Modified LB Film Method

    Institute of Scientific and Technical Information of China (English)

    ZHENG Hua-Jing; JIANG Ya-Dong; XU Jian-Hua; YANG Ya-Jie

    2011-01-01

    Adopting LB film method, an arachidic acid (AA)/PEDOT multilayer LB film and polymerized EDOT monomers in hydrophilic group of LB were chosen to prepare the arachidic acid (AA)/PEDOT multilayer LB film. UV-Vis, FT-IR and XPS analyses implied that EDOT was effectively polymerized in film, and thus PEDOT conducting polymer was produced. Analyses of XRR and SIMS indicated that the film had a well-arranged lamella structure, and further research showed that polymerization of EDOT in AA film destroyed the orderliness of the original LB film. This phenomenon could be related to the destructive effect of polymerization on the layered structure. We used four-point probe and semiconductor instrument to study the conductivity property of the film, and observed that the conductivity of AA/PEDOT film had sudden changes with the changes of processing time in an effective conduction network, which was caused by "permeability" in conducting channel of multilayer film. The test results also indicated that the conductivity of AA/PEDOT film was obviously better than that of spin-coating PEDOT/PSS or ODA-SA/PEDOT-PSS film due to the higher π structure of PEDOT structure and ordered film structure.

  4. Electrochromic behavior of NiO film prepared by e-beam evaporation

    Directory of Open Access Journals (Sweden)

    D.R. Sahu

    2017-06-01

    Full Text Available The NiO thin films were prepared by the electron beam evaporation method using synthesized sintered targets. As-prepared films were characterized using X-ray diffraction, scanning electron microscopy, UV–VIS spectroscopy and cyclic voltammetry. The thicker films were found to exhibit a well-defined structure and a well-developed crystallite size with greater transmittance modulation and durability. The as-deposited thinner films of 170 nm showed a faster response time during electrochromic cycles with a coloration efficiency of 53.1 C/cm2 than the thicker ones. However, the thicker films showed no enhanced electrochromic properties such as a larger intercalated charge than the thinner ones. The electrochromic properties of the thinner films became deteriorated after 800 cycling tests.

  5. Facile Preparation and Characterization of Poly (3-hexylthiophene)/Multiwalled Carbon Nanotube Thermoelectric Composite Films

    Science.gov (United States)

    Du, Y.; Shen, S. Z.; Yang, W. D.; Chen, S.; Qin, Z.; Cai, K. F.; Casey, P. S.

    2012-06-01

    This paper reports a novel, cost-effective, scalable, and simple method for preparing poly(3-hexylthiophene)/multiwalled carbon nanotube (P3HT/MWCNT) nanocomposite films. The P3HT/MWCNT films were prepared by oxidative polymerization of 3-hexylthiophene in chloroform solution containing dispersed MWCNT. The phase composition and microstructure of the composite films were analyzed by x-ray diffraction (XRD), Fourier-transform infrared spectroscopy, Raman spectroscopy, thermogravimetric analysis, and field-emission scanning electron microscopy. The composite films were smooth, dense, and uniform. The thermoelectric properties of the composite films were measured at room temperature. The electrical conductivity and Seebeck coefficient of the films with MWCNT content of 5 wt.% were ~1.3 × 10-3 S/cm and 131.0 μV/K, respectively.

  6. Preparation of ITO transparent conductive film by sol-gel method

    Institute of Scientific and Technical Information of China (English)

    LI Zhi-hua; REN Dong-yan

    2006-01-01

    The ITO transparent conductive films were prepared on substrate of quartz glass by sol-gel method. The raw materials were nitrate indium, acetylacetone and the dopant of anhydrous chloride (SnCl4). The process from gel to crystalline film and the microstructure of the films were investigated by DTA-TG, XRD and SEM. The influence of preparation processes on the electricity performance of the films was also studied by four-probe apparatus. The results show that the crystallization process of ITO xerogel completes when the heat treatment temperature reaches 600 ℃. The ITO films possesses on vesicular structures accumulated by spherical particles, and both heat treatment temperature and cooling rate have important effects on the resistivity ofITO films.

  7. Si/Nanocrystalline Diamond Film Heterojunction Diodes Preparation

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    With electron assisted hot filament chemical vapor deposition technology, nanocrystalline diamond films were deposited on polished n-(100)Si wafer surface. The deposited films were characterized and observed by Raman spectrum, X-ray diffraction, semiconductor characterization system and Hall effective measurement system. The results show that with EA-HFCVD, not only an undoped nanocrystalline diamond films with high-conductivity (p-type semiconducting) but also a p-n heterojunction diode between the nanocrystalline diamond films and n-Si substrate is fabricated successfully. The p-n heterojunction has smaller forward resistance and bigger positive resistance. The p-n junction effective is evident.

  8. Generation of pure spin currents via spin Seebeck effect in self-biased hexagonal ferrite thin films

    Energy Technology Data Exchange (ETDEWEB)

    Li, Peng; Ellsworth, David; Chang, Houchen; Janantha, Praveen; Richardson, Daniel; Phillips, Preston; Vijayasarathy, Tarah; Wu, Mingzhong, E-mail: mwu@lamar.colostate.edu [Department of Physics, Colorado State University, Fort Collins, Colorado 80523 (United States); Shah, Faisal [Department of Electrical Engineering, University of Notre Dame, Notre Dame, Indiana 46556 (United States)

    2014-12-15

    Light-induced generation of pure spin currents in a Pt(2.5 nm)/BaFe{sub 12}O{sub 19}(1.2 μm)/sapphire(0.5 mm) structure is reported. The BaFe{sub 12}O{sub 19} film had strong in-plane uniaxial anisotropy and was therefore self-biased. Upon exposure to light, a temperature difference (ΔT) was established across the BaFe{sub 12}O{sub 19} thickness that gave rise to a pure spin current in the Pt via the spin Seebeck effect. Via the inverse spin Hall effect, the spin current produced an electric voltage across one of the Pt lateral dimensions. The voltage varied with time in the same manner as ΔT and flipped its sign when the magnetization in BaFe{sub 12}O{sub 19} was reversed.

  9. Structural and Dielectric Properties of Bismuth Doped Cobalt Nano Ferrites Prepared by Sol-Gel Auto Combustion Method

    Science.gov (United States)

    Routray, Krutika L.; Behera, Dhrubananda

    2017-02-01

    The present study is focused on the preparation of a series of Bismuth doped CoFe2O4 (CFO) nanoparticles and its structural and dielectric properties. The CFO particles having chemical composition CoBixFe2-xO4 (where x = 0.0, 0.1, 0.5) has been synthesized using sol-gel auto combustion method. Phase formation study of the prepared samples is carried out using X -ray diffraction (XRD) technique. It reveals single phase spinel structure having space group Fd3m. The two absorption bands v 1 and v 2 are observed in Fourier transform infrared spectroscopy (FTIR) spectra corresponding to the tetrahedral and octahedral sites, which show mark of spinel structure of the samples. Morphological study is carried out using Field Emission Scanning Electron Microscope (FESEM) and Transmission Electron Microscopy (TEM) which revealed that the particle size obtained is around 40 nm to 120 nm. In addition, phase formation has been confirmed from the analysis of Raman spectra. Different types of conduction mechanism of the charge carriers have been analysed with DC resistivity and AC impedance measurement at room temperature. Results demonstrate the presence of dielectric relaxation, which is found to be of non-Debye type.

  10. Physical and Degradable Properties of Mulching Films Prepared from Natural Fibers and Biodegradable Polymers

    OpenAIRE

    Zhijian Tan; Yongjian Yi; Hongying Wang; Wanlai Zhou; Yuanru Yang; Chaoyun Wang

    2016-01-01

    The use of plastic film in agriculture has the serious drawback of producing vast quantities of waste. In this work, films were prepared from natural fibers and biodegradable polymers as potential substitutes for the conventional non-biodegradable plastic film used as mulching material in agricultural production. The physical properties (e.g., mechanical properties, heat preservation, water permeability, and photopermeability) and degradation characteristics (evaluated by micro-organic cultur...

  11. Quality by design approach for optimizing the formulation and physical properties of extemporaneously prepared orodispersible films

    NARCIS (Netherlands)

    Visser, J. Caroline; Dohmen, Willem M. C.; Hinrichs, Wouter L. J.; Breitkreutz, Joerg; Frijlink, Henderik W.; Woerdenbag, Herman J.

    2015-01-01

    The quality by design (QbD) approach was applied for optimizing the formulation of extemporaneously prepared orodispersible films (ODFs) using Design-Expert Software. The starting formulation was based on earlier experiments and contained the film forming agents hypromellose and carbomer 974P and th

  12. Disinfection studies on TiO2 thin films prepared by a sol-gel method.

    Science.gov (United States)

    Kambala, Venkata Subba Rao; Naidu, Ravi

    2009-02-01

    Transparent anatase TiO2 nanometer thin films were prepared by dip-coating on soda-lime glass plates via the sol-gel method. The un-calcined and the calcined films were characterized by X-ray diffraction (XRD), AFM, Nano-indentation (hardness and Young's modulus), UV-vis spectrometry, thickness and hydrophilicity (contact angle measurements). The photocatalytic activity of the thin films was evaluated by performing disinfection studies on the Gram-negative microorganisms like Escherichia coli, and Staphylococcus Aureus, a Gram-positive organism. The photocatalytic activity for both groups of organisms was studied in saline and nutrient broth. The leakage of potassium from the bacteria was observed parallel to cell viability. The activity of the sol-gel prepared TiO2 thin films were compared under UV lamps and natural day light (ND) lamps with Degussa P-25 TiO2 thin films prepared on soda-lime glass using a polymer support and the commercial self-cleaning glass (SC). The sol-gel prepared thin films which were annealed at 450 degrees C, show highest photocatalytic activity, the slowest conversion rate from hydrophilic to a hydrophobic state, light-induced hydrophilicity, and also higher disinfection activities compared to P-25 films and commercial self-cleaning glass. The films also show excellent activities when continuously reused for more than a month.

  13. Preparation and characterization of cellulose acetate organic/inorganic hybrid films

    Science.gov (United States)

    Saeed S. Shojaie; Timothy G. Rials; Stephen S. Kelley

    1995-01-01

    A series of organic/inorganic hybrid (OIH) films were prepared using cellulose acetate (CA) as the organic component and tetraethyl orthosilicate (TEOS) as the inorganic component. The chemical, morphological, and mechanical properties of these films were evaluated with a variety of analytical techniques. The results of these evaluations showed that crosslinked CA OIH...

  14. Preparation and Haemocompatibility of Regular Array Microporous PLGA Films on Stainless Steel Surface

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Regular array microporous films from poly ( L-lactic-co-glycolic acid) ( PLGA ) were prepared on stainless steel substrates utilizing the condensation of water droplets on polymer solutions. The size of the pores and regularity can be controlled by atmospheric humidity and concentration of polymer solution. The microporons films have strong hydrophobicity and good haemocompatibility.

  15. Highly conductive free standing polypyrrole films prepared by freezing interfacial polymerization.

    Science.gov (United States)

    Qi, Guijin; Huang, Liyan; Wang, Huiliang

    2012-08-25

    Highly conductive free standing polypyrrole (PPy) films were prepared by a novel freezing interfacial polymerization method. The films exhibit metallic luster and electrical conductivity up to 2000 S cm(-1). By characterizing with SEM, FTIR, Raman and XRD, the high conductivity is attributed to the smooth surface, higher conjugation length and more ordered molecular structure of PPy.

  16. Cell proliferation on modified DLC thin films prepared by plasma enhanced chemical vapor deposition.

    Science.gov (United States)

    Stoica, Adrian; Manakhov, Anton; Polčák, Josef; Ondračka, Pavel; Buršíková, Vilma; Zajíčková, Renata; Medalová, Jiřina; Zajíčková, Lenka

    2015-06-12

    Recently, diamondlike carbon (DLC) thin films have gained interest for biological applications, such as hip and dental prostheses or heart valves and coronary stents, thanks to their high strength and stability. However, the biocompatibility of the DLC is still questionable due to its low wettability and possible mechanical failure (delamination). In this work, DLC:N:O and DLC: SiOx thin films were comparatively investigated with respect to cell proliferation. Thin DLC films with an addition of N, O, and Si were prepared by plasma enhanced CVD from mixtures of methane, hydrogen, and hexamethyldisiloxane. The films were optically characterized by infrared spectroscopy and ellipsometry in UV-visible spectrum. The thickness and the optical properties were obtained from the ellipsometric measurements. Atomic composition of the films was determined by Rutherford backscattering spectroscopy combined with elastic recoil detection analysis and by x-ray photoelectron spectroscopy. The mechanical properties of the films were studied by depth sensing indentation technique. The number of cells that proliferate on the surface of the prepared DLC films and on control culture dishes were compared and correlated with the properties of as-deposited and aged films. The authors found that the level of cell proliferation on the coated dishes was high, comparable to the untreated (control) samples. The prepared DLC films were stable and no decrease of the biocompatibility was observed for the samples aged at ambient conditions.

  17. Studies on tin oxide films prepared by electron beam evaporation and spray pyrolysis methods

    Indian Academy of Sciences (India)

    K S Shamala; L C S Murthy; K Narasimha Rao

    2004-06-01

    Transparent conducting tin oxide thin films have been prepared by electron beam evaporation and spray pyrolysis methods. Structural, optical and electrical properties were studied under different preparation conditions like substrate temperature, solution flow rate and rate of deposition. Resistivity of undoped evaporated films varied from 2.65 × 10-2 -cm to 3.57 × 10-3 -cm in the temperature range 150–200°C. For undoped spray pyrolyzed films, the resistivity was observed to be in the range 1.2 × 10-1 to 1.69 × 10-2 -cm in the temperature range 250–370°C. Hall effect measurements indicated that the mobility as well as carrier concentration of evaporated films were greater than that of spray deposited films. The lowest resistivity for antimony doped tin oxide film was found to be 7.74 × 10-4 -cm, which was deposited at 350°C with 0.26 g of SbCl3 and 4 g of SnCl4 (SbCl3/SnCl4 = 0.065). Evaporated films were found to be amorphous in the temperature range up to 200°C, whereas spray pyrolyzed films prepared at substrate temperature of 300–370°C were polycrystalline. The morphology of tin oxide films was studied using SEM.

  18. Structural, Optical and Magnetic Properties of Ni-Zn Ferrite Nanoparticles Prepared by a Microwave Assisted Combustion Method.

    Science.gov (United States)

    Vijaya, J Judith; Bououdina, M

    2016-01-01

    Ni-doped ZnFe₂O₄(Ni(x)Zn₁₋xFe₂O₄; x = 0.0 to 0.5) nanoparticles were synthesized by a simple microwave combustion method. The X-ray diffraction confirms the presence of cubic spinel ZnFe₂O₄for all compositions. The lattice parameter decreases with an increase in Ni content resulting in the reduction of lattice strain. High resolution scanning electron microscope images revealed that the as-prepared samples are crystalline with particle size distribution in 40-50 nm range. Optical properties were determined by UV-Visible diffuse reflectance and photoluminescence spectroscopy respectively. The saturation magnetization (Ms) shows the super paramagnetic nature of the sample for x = 0.0-0.2, whereas for x = 0.3-0.5, it shows ferromagnetic nature. The Ms value is 1.638 emu/g for pure ZnFe₂O₄ sample and it increases with increase in Ni content.

  19. Strontium-Doped Lanthanum Manganite Films Prepared by Magnetic Deposition

    DEFF Research Database (Denmark)

    Menon, Mohan; Larsen, Casper; Andersen, Kjeld Bøhm

    2009-01-01

    Deposition of La0.85Sr0.15MnO3 (LSM) films from suspensions using a magnetic field was found to be a cheap and quick technique. Ninety weight percent of the particles present in the suspensions were deposited within the first minute of the deposition, and the thickness of the film varied linearly...

  20. Preparation and Characterization of Neutral and Oxidized Polypyrrole Films.

    Science.gov (United States)

    1981-08-31

    oxidation of the pyrrole was obtained from cyclic voltametry in a two-compartment electrochemical cell. If TBAP was used as the electrolyte salt in both...bronze color; thin transparent films are grey. The room temperature electrical conductivity of the films is -50 ohm ŕ cmŕ. Cyclic voltammetry showed that

  1. Characterization of Plasma Polymerized Hexamethyldisiloxane Films Prepared by Arc Discharge

    NARCIS (Netherlands)

    Lazauskas, A.; Baltrusaitis, Jonas; Grigaliunas, V.; Jucius, D; Guobiene, A.; Prosycevas, I.; Narmontas, P.

    2014-01-01

    Herein, we present a simple method for fabricating plasma polymerized hexamethyldisiloxane films (pp-HMDSO) possessing superhydrophobic characteristics via arc discharge. The pp-HMDSO films were deposited on a soda–lime–silica float glass using HMDSO monomer vapor as a precursor. A detailed surface

  2. Low-temperature preparation of anatase thin films on tantalum.

    Science.gov (United States)

    Johnson, Scott E; Burgoon, Matthew W P; Wang, Qi; White, J M

    2006-07-18

    Titanium dioxide thin films were grown on oxidized Ta surfaces using a cyclic layer-by-layer wet chemistry method: successive-ionic-layer-adsorption-and-reaction (SILAR). Film thicknesses varied monotonically and approximately linearly with the number of cycles. As-grown (AG) films were amorphous and rougher (16.2 nm root-mean-square (rms)) than the Ta substrate (10.2 nm rms). After hydrothermal annealing (AN) at a remarkably low temperature of 393 K, the films exhibited anatase crystallites (10 nm dimensions) and reduced roughness (11.8 nm rms). The atomic composition of both AG and AN films was consistent with that of TiO2 containing no more than 4 atom % carbon. A small Si impurity (<1 atom %) was eliminated by using polypropylene beakers and sample holders in the SILAR steps.

  3. Optical properties of rubrene thin film prepared by thermal evaporation

    Institute of Scientific and Technical Information of China (English)

    陈亮; 邓金祥; 孔乐; 崔敏; 陈仁刚; 张紫佳

    2015-01-01

    Rubrene thin films are deposited on quartz substrates and silver nanoparticles (Ag NPs) films by the thermal evapo-ration technique. The optical properties of rubrene thin film are investigated in a spectral range of 190 nm–1600 nm. The analysis of the absorption coefficient (α) reveals direct allowed transition with a corresponding energy of 2.24 eV. The photoluminescence (PL) peak of the rubrene thin film is observed to be at 563 nm (2.21 eV). With the use of Ag NPs which are fabricated by radio-frequency (RF) magnetron sputtering on the quartz, the PL intensity is 8.5 times that of as-deposited rubrene thin film. It is attributed to the fact that the surface plasmon enhances the photoluminescence.

  4. Preparation of Cu2ZnSnS4 thin films by hybrid sputtering

    Science.gov (United States)

    Tanaka, Tooru; Nagatomo, Takeshi; Kawasaki, Daisuke; Nishio, Mitsuhiro; Guo, Qixin; Wakahara, Akihiro; Yoshida, Akira; Ogawa, Hiroshi

    2005-11-01

    In order to fabricate Cu2ZnSnS4 thin films, hybrid sputtering system with two sputter sources and two effusion cells is used. The Cu2ZnSnS4 films are fabricated by the sequential deposition of metal elements and annealing in S flux, varying the substrate temperature. The Cu2ZnSnS4 films with stoichiometric composition are obtained at the substrate temperature up to 400 °C, whereas the film composition becomes quite Zn-pool at the substrate temperature above 450 °C. The Cu2ZnSnS4 film shows p-type conductivity, and the optical absorption coefficient and the band gap of the Cu2ZnSnS4 film prepared in this experiment are suitable for fabricating a thin film solar cell.

  5. Preparation and Characterization of Self-Assembled Manganese Dioxide Thin Films

    Directory of Open Access Journals (Sweden)

    Suh Cem Pang

    2011-01-01

    Full Text Available Thin films of manganese dioxide (MnO2 were prepared by self-assembly of MnO2 nanoparticles directly unto nickel-coated poly(ethylene terephthalate flexible films using the newly developed horizontal submersion process. The thickness of deposited thin films was controllable by the deposition duration. This horizontal submersion deposition process for thin-film deposition is relatively easy, simple, and cost effective. Effects of deposition duration and calcination temperatures on the microstructure and electrochemical properties of self-assembled MnO2 thin films were investigated. Optimized MnO2 thin films exhibited high charge capacity, good cycling reversibility, and stability in a mild aqueous electrolyte and are thus promising electrode materials for the fabrication of thin-film electrochemical capacitors.

  6. Properties of TiO2 Thin Films Prepared by Magnetron Sputtering

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    With rapid progressive application of TiO2 thin films, magnetron sputtering becomes a very interesting method to prepare such multi-functional thin films. This paper focuses on influences of various deposition processes and deposition rate on the structures and properties of TiO2 thin films. Anatase, rutile or amorphous TiO2 films with various crystalline structures and different photocatalytic, optical and electrical properties can be produced by varying sputtering gases, substrate temperature, annealing process, deposition rate and the characteristics of magnetron sputtering. This may in turn affect the functions of TiO2 films in many applications. Furthermore, TiO2-based composites films can overcome many limitations and improve the properties of TiO2 films.

  7. Surface and Electrical Properties of NiCr Thin Films Prepared by DC Magnetron Sputtering

    Institute of Scientific and Technical Information of China (English)

    ZHOU Jicheng; TIAN Li; YAN Jianwu

    2008-01-01

    Several batches of NiCr alloy thin films with different thickness were prepared in a multi-targets magnetron sputtering apparatus by changing sputtering time while keeping sputtering target power of Ni and Cr fixed. Then the as-deposited films were characterized by energy-dispersive X-Ray spectrometer (EDX),Atomic Force Microscope (AFM) and four-point probe (FPP) to measure surface grain size, roughness and sheet resistance. The film thickness was measured by Alpha-Step IQ Profilers. The thickness dependence of surface roughness, lateral grain size and resistivity was also studied. The experimental results show that the grain size increases with film thickness and the surface roughness reaches the order of nanometer at all film thickness. The as-deposited film resistivity decreases with film thickness.

  8. Ferrites and ceramic composites

    CERN Document Server

    Jotania, Rajshree B

    2013-01-01

    The Ferrite term is used to refer to all magnetic oxides containing iron as major metallic component. Ferrites are very attractive materials because they simultaneously show high resistivity and high saturation magnetization, and attract now considerable attention, because of the interesting physics involved. Typical ferrite material possesses excellent chemical stability, high corrosion resistivity, magneto-crystalline anisotropy, magneto-striction, and magneto-optical properties. Ferrites belong to the group of ferrimagnetic oxides, and include rare-earth garnets and ortho-ferrites. Several

  9. Physical and Degradable Properties of Mulching Films Prepared from Natural Fibers and Biodegradable Polymers

    Directory of Open Access Journals (Sweden)

    Zhijian Tan

    2016-05-01

    Full Text Available The use of plastic film in agriculture has the serious drawback of producing vast quantities of waste. In this work, films were prepared from natural fibers and biodegradable polymers as potential substitutes for the conventional non-biodegradable plastic film used as mulching material in agricultural production. The physical properties (e.g., mechanical properties, heat preservation, water permeability, and photopermeability and degradation characteristics (evaluated by micro-organic culture testing and soil burial testing of the films were studied in both laboratory and field tests. The experimental results indicated that these fiber/polymer films exhibited favorable physical properties that were sufficient for use in mulching film applications. Moreover, the degradation degree of the three tested films decreased in the following order: fiber/starch (ST film > fiber/poly(vinyl alcohol (PVA film > fiber/polyacrylate (PA film. The fiber/starch and fiber/PVA films were made from completely biodegradable materials and demonstrated the potential to substitute non-biodegradable films.

  10. 活性炭负载镍锌铁氧体的制备及电磁性能研究%Preparation and electromagnetism property of activated carbon loaded with Ni-Zn ferrite

    Institute of Scientific and Technical Information of China (English)

    安玉良; 李杰; 袁霞; 隋宏超

    2014-01-01

    以柠檬酸为络合剂制备镍锌铁氧体溶胶,以活性炭为基体负载 Ni-Zn 铁氧体,再通过焙烧制备出形态和结构理想的活性炭/镍锌铁氧体复合材料;详细地考察烧结温度、煅烧气氛及活性炭与铁氧体的配比等工艺参数对复合材料的形态和结构的影响;分别采用X射线衍射(XRD)和扫描电镜(SEM)对制备出的复合材料进行形貌、结构表征分析.采用波导法在8.2~12.4 GHz波段对活性炭负载纳米镍锌铁氧体复合材料进行电磁参数测试,结果表明所制备活性炭负载镍锌铁氧体复合材料具有较高的电、磁损耗角正切值,其吸波性能较好.%The Ni-Zn ferrite sol was synthesized with citric acid as complexing reagent,and the ferrite and activa-ted carbon composite gel was obtained by vaporization treatment,then the activated carbon loaded with Ni-Zn ferrite composite was prepared by calcination treatment of the gel.The effect of process parameters such as the sintering temperature,sintering gas and ratio of carbon/ferrite on the morphology and structure of composite were studied in detail,in which the morphology,structure and compose of composite were characterized by scanning electron microscopy (SEM)and elements X-ray diffraction (XRD).Furthermore,the complex permit-tivity and permeability of the as-prepared composites were characterized in the frequency ranges of 8.2-12.4 GHz by the wave-guide method on the vector network analyzer,in which the higher electrical and magnetic loss tan-gent values of the activated carbon loaded with Ni-Zn ferrite composite were obtained.

  11. Preparation of transparent TiO2 nanocrystalline film for UV sensor

    Institute of Scientific and Technical Information of China (English)

    FU Yao; GAO Wanghe

    2006-01-01

    The nanocrystalline TiO2 film electrodes were prepared by sol-gel method at different calcining temperatures, which had characteristics of different film thickness, uniform transparency, as well as high photoelectric and mechanical stability. Photoelectric measurements show that calcining temperature and film thickness could remarkably influence the photoelectric properties of the electrodes. The film calcined at 450℃ is anatase phase with high crystallinity and strong photoelectric activity, and shows the largest photocurrent. When the temperature is lower than 450℃, the film has weaker crystallinity because of a large number of defects in the film,and this is not favorable for the transport of the photogenerated carriers. And at a temperature higher than 450℃, the photocurrent of the electrode is decreased due to anatase-rutile phase transition in the film. The increase in film thickness is favorable to the enhancement of ultraviolet light (UV) absorption amount, which would improve the photoelectric activity of the film. But, excessive thickness will increase the recombination rate of the electron-hole pairs, and result in a reduction in electrode's photoelectric activity. In addition, the response sensitivity and stability of the photocurrent produced in the electrode are related to bias potential. At a potential of 0.4 V, the electrode shows a saturated photocurrent of 30.8 μA and a response time of ~1 s, suggesting that the prepared TiO2 film electrode can be used for making UV sensors.

  12. Self-assembled mesoporous Co and Ni-ferrite spherical clusters consisting of spinel nanocrystals prepared using a template-free approach.

    Science.gov (United States)

    Yu, Byong Yong; Kwak, Seung-Yeop

    2011-10-21

    Based on a self-assembly strategy, spherical mesoporous cobalt and nickel ferrite nanocrystal clusters with a large surface area and narrow size distribution were successfully synthesized for the first time via a template-free solvothermal process in ethylene glycol and subsequent heat treatment. In this work, the mesopores in the ferrite clusters were derived mainly from interior voids between aggregated primary nanoparticles (with crystallite size of less than 7 nm) and disordered particle packing domains. The concentration of sodium acetate is shown herein to play a crucial role in the formation of mesoporous ferrite spherical clusters. These ferrite clusters were characterized in detail using wide-angle X-ray diffraction, thermogravimetric-differential thermal analysis, (57)Fe Mössbauer spectroscopy, X-ray photoelectron spectroscopy, field-emission scanning electron microscopy, standard and high-resolution transmission electron microscopy, and other techniques. The results confirmed the formation of both pure-phase ferrite clusters with highly crystalline spinel structure, uniform size (about 160 nm) and spherical morphology, and worm-like mesopore structures. The BET specific surface areas and mean pore sizes of the mesoporous Co and Ni-ferrite clusters were as high as 160 m(2) g(-1) and 182 m(2) g(-1), and 7.91 nm and 6.87 nm, respectively. A model for the formation of the spherical clusters in our system is proposed on the basis of the results. The magnetic properties of both samples were investigated at 300 K, and it was found that these materials are superparamagnetic.

  13. Raman spectroscopy of chalcogenide thin films prepared by PLD

    Energy Technology Data Exchange (ETDEWEB)

    Erazu, M.; Rocca, J. [Laboratorio de Solidos Amorfos, INTECIN, Facultad de Ingenieria, Universidad de Buenos Aires - CONICET, Paseo Colon 850, 1063 Buenos Aires (Argentina); Fontana, M., E-mail: merazu@fi.uba.a [Laboratorio de Solidos Amorfos, INTECIN, Facultad de Ingenieria, Universidad de Buenos Aires - CONICET, Paseo Colon 850, 1063 Buenos Aires (Argentina); Urena, A.; Arcondo, B. [Laboratorio de Solidos Amorfos, INTECIN, Facultad de Ingenieria, Universidad de Buenos Aires - CONICET, Paseo Colon 850, 1063 Buenos Aires (Argentina); Pradel, A. [ICG, UMR 5253 CNRS UM 2 ENSCM UM1 equipe PMDP CC3, Universite Montpellier 2, 34095 Montpellier Cedex 5 (France)

    2010-04-16

    Chalcogenide glasses have many technological applications as a result of their particular optical and electrical properties. Ge-Se and Ag-Ge-Se systems were recently studied and tested as new materials for building non-volatile memories. Following these ideas, thin films of Ge-Se and Ag-Ge-Se were deposited using pulsed laser deposition (PLD). Ag was sputtered over binary films (for a composition between 0.05 and 0.25 Ag atomic fraction) and photo-diffused afterwards. Thus, three kinds of samples were analyzed by means of Raman spectroscopy, in order to provide information on the short- and medium-range order: PLD binary films before Ag doping, after Ag doping and PLD ternary films. Before Ag doping, binary films exhibited Ge-Se corner-sharing tetrahedra modes at 190 cm{sup -1}, low scattering from edge-sharing tetrahedra at 210 cm{sup -1}, and Se chains at 260 cm{sup -1} (stretching mode). However, after the diffusion process was complete, we observed an intensity reduction of bands centered at 210 cm{sup -1} and 260 cm{sup -1}. The spectra of the photo-diffused films were similar to those of films deposited using a ternary target. Relaxation effects in binary glasses were also analyzed. Results were compared with those of other authors.

  14. Preparation of iron cobaltite thin films by RF magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Le Trong, H. [Université de Toulouse, UPS, INPT, Institut Carnot CIRIMAT, 118, Route de Narbonne, F-31062 Toulouse cedex 9 (France); CNRS, Institut Carnot Cirimat, F-31062 Toulouse (France); Ho Chi Minh City University of Science, Vietnam National University Ho Chi Minh City, 227 Nguyen Van Cu Q 5, 750000 Ho Chi Minh City (Viet Nam); Bui, T.M.A. [Université de Toulouse, UPS, INPT, Institut Carnot CIRIMAT, 118, Route de Narbonne, F-31062 Toulouse cedex 9 (France); CNRS, Institut Carnot Cirimat, F-31062 Toulouse (France); University of Transport and Communications, Lang Thuong, Dong Da, Hanoi (Viet Nam); Presmanes, L., E-mail: presmane@chimie.ups-tlse.fr [Université de Toulouse, UPS, INPT, Institut Carnot CIRIMAT, 118, Route de Narbonne, F-31062 Toulouse cedex 9 (France); CNRS, Institut Carnot Cirimat, F-31062 Toulouse (France); Barnabé, A.; Pasquet, I.; Bonningue, C.; Tailhades, Ph. [Université de Toulouse, UPS, INPT, Institut Carnot CIRIMAT, 118, Route de Narbonne, F-31062 Toulouse cedex 9 (France); CNRS, Institut Carnot Cirimat, F-31062 Toulouse (France)

    2015-08-31

    Iron cobaltite thin films with spinel structure have been elaborated by radio-frequency (RF) magnetron sputtering from a Co{sub 1.75}Fe{sub 1.25}O{sub 4} target. Influence of argon pressure on structure, microstructure and physical properties of films has been examined. Iron–cobalt oxide thin films essentially consist of one spinel phase when deposited at low pressure (0.5 and 1.0 Pa). At high pressure (2.0 Pa), the global stoichiometry of the film is changed which results in the precipitation of a mixed monoxide of cobalt and iron beside the spinel phase. This in-situ reduction due to an oxygen loss occurring mainly at high deposition pressure has been revealed by X-ray diffraction and Raman spectroscopy. Microstructural evolution of thin film with argon pressure has been shown by microscopic observations (AFM and SEM). The evolution of magnetic and electrical properties, versus argon pressure, has been also studied by SQUID and 4 point probe measurements. - Highlights: • Co{sub 1.75}Fe{sub 1.25}O{sub 4} phase is obtained at room temperature without any annealing. • This phase is a ferrimagnetic semiconductor with a coercive field of 32 kOe at 5 K. • Oxygen content of the thin film is related to the argon pressure during sputtering. • Monoxide phase grows into the film at high argon pressure. • Magnetic coupling effect reveals nanoscale impurities at low argon pressure.

  15. Field Emission Properties of the Graphene Double-Walled Carbon Nanotube Hybrid Films Prepared by Vacuum Filtration and Screen Printing

    OpenAIRE

    Jinzhuo Xu; Tao Feng; Yiwei Chen; Zhuo Sun

    2013-01-01

    The graphene double-walled carbon nanotube (DWCNT) hybrid films were prepared by vacuum filtration and screen printing. Their electron field emission properties have been studied systematically. The electron emission properties of the hybrid films are much better than those of pure DWCNT films and pure graphene films. Comparing with the screen printed films, the vacuum filtered films have many advantages, such as lower turn-on field, higher emission current density, better uniformity, better ...

  16. Polymer bonded ferrite materials as EMC components

    Energy Technology Data Exchange (ETDEWEB)

    Toepfer, J. [Fachhochschule Jena, FB Werkstofftechnik, Carl-Zeiss-Promenade 2, 07745 Jena (Germany); Hermsdorfer Institut fuer Technische Keramik e.V., M.-Curie-Str. 17, 07629 Hermsdorf (Germany); Pawlowski, B. [Hermsdorfer Institut fuer Technische Keramik e.V., M.-Curie-Str. 17, 07629 Hermsdorf (Germany); Graebner, F. [IMG Nordhausen, An der Salza 8a, 99734 Nordhausen (Germany)

    2003-07-01

    Polymer bonded ferrites composed of a mixture of Mn-Zn ferrites or Ni-Zn ferrites in a polymer binder (PE, PA) were prepared and tested as electromagnetic-wave absorbing materials. Test samples and cases were prepared by hot or injection molding. Permeability spectra show loss contributions in the frequency range 100-1000 MHz. Absorption measurements of injection molded polymer-ferrite cases display a 3-5 dB better attenuation characteristics compared to graphite-loaded polyamide housings. (Abstract Copyright [2003], Wiley Periodicals, Inc.) [German] Polymer-gebundene Ferritwerkstoffe auf der Basis von Ferrit (Mn-Zn oder Ni-Zn Ferrite) - Thermoplast Mischungen wurden praepariert und hinsichtlich ihrer Eignung zur Absorption elektromagnetischer Strahlung untersucht. Es wurden sowohl Testproben wie auch komplette Gehaeusekomponenten durch Heisspressen oder Spritzgiessen hergestellt. Die Permeabilitaetsspektren weisen verlustbehaftete Komponenten im Frequenzbereich von 100-1000 MHz auf. Schirmdaempfungsmessungen an spritzgegossenen Gehaeuseteilen zeigen eine um 3-5 dB bessere Daempfung im Vergleich zu Graphit-gefuellten Polyamid-Gehaeusen. (Abstract Copyright [2003], Wiley Periodicals, Inc.)

  17. Preparation and characterization of sponge film made from feathers

    Energy Technology Data Exchange (ETDEWEB)

    Zhuang, Yuan; Wu, Xiaoqian [College of Environmental Science and Engineering, Donghua University, Shanghai 201620 (China); Cao, Zhangjun [College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620 (China); Zhao, Xiaoxiang; Zhou, Meihua [College of Environmental Science and Engineering, Donghua University, Shanghai 201620 (China); Gao, Pin, E-mail: gaopin@mail.dhu.edu.cn [College of Environmental Science and Engineering, Donghua University, Shanghai 201620 (China)

    2013-12-01

    Feather wastes generated from poultry farms will pose a problem for disposal, but they are sustainable resources of keratin. Reduction is one of the commonly used methods to obtain soluble keratin from feather. However, the residues generated during feather reduction reaction were rarely investigated. In this study, the residues were transformed into a porous and flexible sponge film by freeze-drying without pretreatment or addition of cross-linking agents. Glycerol was used to alter the physical and chemical characteristics of the sponge film. The film was characterized with a fiber strong stretch instrument, a Fourier transform infrared spectrophotometer, scanning electron microscopy, an elemental analyzer, a differential scanning calorimeter and an automatic air permeability apparatus. Tensile strength and melting point of the sponge film with the optimum glycerol content were 6.2 MPa and 170 °C respectively. Due to air permeability of 368 mm/s, the film can potentially be used in medicine, biology, textile, environmental technology, and so on. It is ecologically friendly and will produce additional benefits from the renewable materials. The film was utilized as adsorbents to remove Cr(VI) from aqueous solutions and as a filtering material for air pollution. Its maximum Cr(VI) uptake capacity was about 148.8 mg/g and the removal rate of PM{sub 10} was 98.3%. - Graphical abstract: The reduction residues were made into a smooth, elastic, porous and flexible sponge film through freeze drying, no pretreatment and no cross-linking agent added. - Highlights: • The residue from feather waste reduction was turned into a sponge film. • A glycerol content of 5% produced a sponge with the optimum characteristics. • The sponge was uniform, stable up to 160 °C, and had an air permeability of 368 mm/s. • Feather-derived sponge film has potential applications in medicine and technology.

  18. Comparison of physicomechanical properties of films prepared from organic solutions and aqueous dispersion of Eudragit RL

    Directory of Open Access Journals (Sweden)

    H Afrasiabi Garekani

    2011-05-01

    Full Text Available Background and the purpose of the study: Mechanical properties of films prepared from aqueous dispersion and organic solutions of Eudragit RL were assessed and the effects of plasticizer type, concentration and curing were examined. Methods: Films were prepared from aqueous dispersion and solutions of Eudragit RL (isopropyl alcohol-water 9:1 containing 0, 10 or 20% (based on polymer weight of PEG 400 or Triethyl Citrate (TEC as plasticizer using casting method. Samples of films were stored in oven at 60ºC for 24 hrs (Cured. The stress-strain curve was obtained for each film using material testing machine and tensile strength, elastic modulus, %elongation and work of failure were calculated. Results and major conclusion: The films with no plasticizer showed different mechanical properties depending on the vehicle used. Addition of 10% or 20% of plasticizer decreased the tensile strength and elastic modulus and increased %elongation and work of failure for all films. The effect of PEG400 on mechanical properties of Eudragit RL films was more pronounced. The differences in mechanical properties of the films due to vehicle decreased by addition of plasticizer and increase in its concentration. Curing process weakened the mechanical properties of the films with no plasticizer and for films with 10% plasticizer no considerable difference in mechanical properties was observed before and after curing. For those with 20% plasticizer only films prepared from aqueous dispersion showed remarkable difference in mechanical properties before and after curing. Results of this study suggest that the mechanical properties of the Eudragit RL films were affected by the vehicle, type of plasticizer and its concentration in the coating liquid.

  19. Comparison of barium titanate thin films prepared by inkjet printing and spin coating

    Directory of Open Access Journals (Sweden)

    Jelena Vukmirović

    2015-09-01

    Full Text Available In this paper, barium titanate films were prepared by different deposition techniques (spin coating, office Epson inkjet printer and commercial Dimatix inkjet printer. As inkjet technique requires special rheological properties of inks the first part of the study deals with the preparation of inks, whereas the second part examines and compares structural characteristics of the deposited films. Inks were synthesized by sol-gel method and parameters such as viscosity, particle size and surface tension were measured. Deposited films were examined by optical and scanning electron microscopy, XRD analysis and Raman spectroscopy. The findings consider advantages and disadvantages of the particular deposition techniques.

  20. Preparation and characterization of perfluorosulfonic resin/titania hybrid transparent films

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Preparation and characterization of perfluorosulfonic resin/titania organic-inorganic hybrid films were presented. The transparent hybrid films were prepared by hydrothermal treatment at low temperature of a mixed solution of tetrabutyl titanate and perfluorosulfonic resin with the help of acetylacetone. The characterization was carried out by SEM,XRD,FT-IR,UV-Vis and TGA. The results showed that the perfluorosulfonic resin/titania hybrid transparent films were composed of titania particles dispersed in the perfluorosulfonic resin matrix very well and the titania was of anatase phase. Its diameter de-creased with increasing weight ratio of titania to perfluorosulfonic resin.

  1. Preparation and characterization of perfluorosulfonic resin/titania hybrid transparent films

    Institute of Scientific and Technical Information of China (English)

    LI JianMei; XUE MinZhao; ZHANG YongMing; LIU YanGang

    2007-01-01

    Preparation and characterization of perfluoroaulfonic resin/titaniaorganic-inorganic hybrid films were presented. The transparent hybrid films were prepared by hydrothermal treatment at low temperature of a mixed solution of tetrabutyl titanata and perfluorosulfonic resin with the help of acetylacetone. The charactarization was carried out by SEM, XRD, FT-IR, UV-Vis and TGA. The results showed that the perfiuorosulfonic resin/titania hybrid transparent films were composed of titania particles dispersed in the perfluorosulfonic resin matrix very well and the titania was of anatase phase. Its diameter decreased with increasing weight ratio of titania to perfluorosulfonic resin.

  2. Structural and magnetic properties of Ni{sub 0.8}Co{sub 0.2−2x}Cu{sub x}Mn{sub x}Fe{sub 2}O{sub 4} spinel ferrites prepared via solution combustion route

    Energy Technology Data Exchange (ETDEWEB)

    Jadhav, Pragati [Thick and Thin Film Device Laboratory, Department of Physics, Shivaji University, Kolhapur 416004, Maharashtra (India); Patankar, Ketaki, E-mail: ketakiketan@gmail.com [Department of Physics, Rajaram College, Kolhapur 416004, Maharashtra (India); Mathe, Vikas [Novel Materials Research Laboratory, Department of Physics, Savitribai Phule University, Pune 411007, Maharashtra (India); Tarwal, N.L. [Lal Bahadur Shastri College, Satara 415001 (India); Research Institute for Solar and Sustainable Energies (RISE), Gwangju Institute of Science and Technology (GIST), Gwangju 500 712 (Korea, Republic of); Jang, Jae-Hung [Research Institute for Solar and Sustainable Energies (RISE), Gwangju Institute of Science and Technology (GIST), Gwangju 500 712 (Korea, Republic of); Puri, Vijaya, E-mail: vrp_phy@unishivaji.ac.in [Thick and Thin Film Device Laboratory, Department of Physics, Shivaji University, Kolhapur 416004, Maharashtra (India)

    2015-07-01

    Ni{sub 0.8}Co{sub 0.2−2x}Cu{sub x}Mn{sub x}Fe{sub 2}O{sub 4} ferrites (with x=0.01, 0.03, 0.05, 0.07 and 0.09) were prepared using solution combustion route. X-ray diffraction analysis indicates the presence of the characteristic most intense (311) peak along with other reflections confirming the formation of spinel ferrite in each composition. SEM images show formation of porous structured agglomerates with submicron sized grains. The microstrain measurement of ferrite series is non-linear with variation in dopant concentration for a given magnetic field. The magnetic hysteresis at room temperature indicates the ferrimagnetic behavior of synthesized ferrite system. The magnetic and mechanical properties were seen to be comparatively higher for x=0.07 composition. The presence of sexset in Mössbauer spectra confirms the ferrimagnetic nature of all the ferrites. - Highlights: • Quaternary ferrites prepared by solution combustion route reported for the first time. • The pole to pole variation in the immediately close compositions has been reported for the first time and explained in the light of cation distribution. • x=0.07 composition yields better magnetic as well as magnetomechanical properties.

  3. Preparation and Magnetic Property of Lanthanon Doped Mn-Zn Ferrite%稀土元素掺杂Mn-Zn铁氧体的制备及磁性能

    Institute of Scientific and Technical Information of China (English)

    罗广圣; 姜贵文; 刘兵发; 周正有

    2012-01-01

    Lanthanon doped Mn-Zn ferrites (Mn0.5. Zn0.5RExFe-xO4) were prepared by using oxide coprecipitation method with FeSO, · 7H2O,MnSO4 · H2O,ZnSO4 · 7H2Oand RE2O3(RE=Y,Nd,Gd,Dy),HCl as the raw materials, sodium hydroxide solution as the precipitating agent and hydrogen peroxide as the oxidizing reagent. The samples of Mn0.5Z0.5RExFez-xO4 were characterized by FT-IR,XRD and VSM The effect of lanthanon doping category and amount were discussed on structure and magnetic properties of Mn-Zn ferrites. The experiment results indicate that lanthanon doping amount should not exceed 0.02 to maintain Mn-Zn ferrites" regular cubic spinal crystal structure and their good magnetic properties. The average crystalline size of Mn-Zn ferrites' particles decrease monotonously with the increasing of the content (X) and the saturation magnetization intensity of doped lanthanon Y or Nd of Mn-Zn ferrites is weakening, while the saturation magnetization intensity of a few amount of doped lanthanon Gd or Dy of Mn-Zn ferrites is greater than that of pure Mn-Zn ferrites. At x=0.02,the saturation magnetization intensity of doped lanthanon Gd or Dy of Mn-Zn ferrites reached the maximum of 26. 5 emu/g and 29. 3 emu/g respectively.%以FeSO4·7H2O、MnSO4·H2O、ZnSO4·7H2O、RE2O3 (RE=Y、Nd、Gd、Dy)、HC1为原料,NaOH溶液为沉淀剂、H2 O2为氧化剂,采用氧化共沉淀法制备出稀土元素掺杂(RE=Y、Nd、Gd、Dy) Mn-Zn铁氧体(Mn0.5Zn0.5RExFe1-zO4),通过傅里叶变换红外光谱仪(IR),X射线衍射仪(XRD)和振动样品磁强计(VSM)对样品进行表征,讨论了稀土元素掺杂的种类和量对样品的结构和磁性能的影响.结果表明:要得到单相尖晶石结构Mn-Zn铁氧体,稀土元素掺杂量应控制在x≤0.02;Mn0.5Zn0.5RExFe1-xO4的晶粒度随掺杂含量x的增大单调减少;掺杂稀土元素Y、Nd对Mn-Zn铁氧体的磁性有削弱作用,不宜掺杂;而少量的稀土元素Gd、Dy掺杂有利于样品的饱和磁化强度的提高,x=0.02

  4. Temperature stabilization of microwave ferrite devices

    Science.gov (United States)

    Kaminsky, R.; Wendt, E. J.

    1978-01-01

    Thin-film heating element for strip-line circulator is sandwiched between insulation and copper laminations. Disks conform to shape of circulator ferrite disks and are installed between copper-clad epoxy ground planes. Heater design eliminates external cartridges and reduces weight by approximately one-third.

  5. Synthesis and Properties of ZnO/Al Thin Films Prepared by Dip-Coating Process

    OpenAIRE

    Juhņeviča, I; Mašonkina, M; Mežinskis, G; Gabrene, A

    2015-01-01

    In this work sol–gel dip-coating technique was used to synthesize ZnO and ZnO/Al films. The influence of annealing regime and dopant concentration on the structural properties of ZnO and aluminum doped ZnO (ZnO/Al) films was investigated. The surface morphology and crystallinity of ZnO films were determined using atomic force microscopy and Xray diffraction, respectively. The experimental results show that ZnO and ZnO/Al films prepared using “shock” conditions have smo...

  6. Study of photoconductivity in Ni doped CdS thin films prepared by spray pyrolysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Patidar, Manju Mishra, E-mail: manjumishra.iuc@gmail.com; Gangrade, Mohan; Nath, R.; Ganesan, V. [UGC-DAE Consortium for Scientific Research, Khandawa Road, Indore 452001 (India); Ajay, Akhil [Physics Department, University of Delhi, Delhi-110007 (India); Wala, Arwa Dewas [Holkar Science College, Indore - 452001 (India); N, Kiran [Physics Department, University of Mysore, Mysore-570005 (India); Panda, Richa [AITR, Bhopal-462044 (India)

    2014-04-24

    Ni-doped cadmium sulphide [Cd{sub 1−x}Ni{sub x}S, (x=0, 0.03, 0.05 and 0.20)] thin films were investigated for photoconductive properties. The films were prepared by spray Pyrolysis technique (SPT). AFM and two probe resistivity measurements were carried out to analyze the morphological and electrical properties of the films. AFM shows the note worthy changes in the morphology where the nanorod structures in CdS is changed into nano particles with the Ni doping. The presence of persistence photo current is demonstrated and extensive photoconductivity analysis has been studied on these films.

  7. Preparation of self-sustained film by sol-gel method

    Institute of Scientific and Technical Information of China (English)

    曹冰; 朱从善

    1999-01-01

    Large size self-sustained film with considerable thickness ranging from 30 to 500 μm was prepared with sol-gel method by using dimethyldiethoxysilane/tetraethoxysilane composite alkoxide as precursor. The film exhibits good plasticity as well. Various factors that may influence the film properties were investigated. IR and AFM techniques were adopted to study the film structure and surface morphology. Gas chromatogram/mass spectrum technique was also adopted to characterize the network structure of the material through identification of different polymers formed during hydrolysis and condensation course.

  8. Electrochemical preparation of La-Co-Fe alloy films in dimethylsulfoxide (DMSO)

    Institute of Scientific and Technical Information of China (English)

    袁定胜; 黄开胜; 刘冠昆; 童叶翔; 沙励嫦

    2001-01-01

    Potentiostatic and pulse electrolysis techniques were used to prepare La-Co-Fe alloy films using ethylenediamine (EN) as complexant. Surfaces of alloy films obtained by these two techniques are smooth, adhesive, compact and metallic luster. The contents of La in alloy films obtained by potentiostatic electrolysis technique are in the range of 13.23%~47.67%. The contents of La in alloy films deposited by pulse electrolysis technique are in the range of 10.67%~16.29%.

  9. Preparation and characterization of ZnTe thin films by SILAR method

    Energy Technology Data Exchange (ETDEWEB)

    Kale, S.S. [Inorganic Nano-Materials Laboratory, Department of Chemistry, Hanyang University, Sungdong-Ku, Seoul 133-791 (Korea, Republic of); Mane, R.S. [Inorganic Nano-Materials Laboratory, Department of Chemistry, Hanyang University, Sungdong-Ku, Seoul 133-791 (Korea, Republic of); Pathan, H.M. [Eco-Nano Research Centre, Korea Institute of Science and Technology, P.O. Box 131, Chongryang, Seoul 130-650 (Korea, Republic of); Shaikh, A.V. [AKI' s Poona College of Arts, Science and Commerce, Pune (India); Joo, Oh-Shim [Eco-Nano Research Centre, Korea Institute of Science and Technology, P.O. Box 131, Chongryang, Seoul 130-650 (Korea, Republic of); Han, Sung-Hwan [Inorganic Nano-Materials Laboratory, Department of Chemistry, Hanyang University, Sungdong-Ku, Seoul 133-791 (Korea, Republic of)]. E-mail: shhan@hanyang.ac.kr

    2007-02-28

    Nanocrystalline zinc telluride (ZnTe) thin films were prepared by using successive ionic layer adsorption and reaction (SILAR) method from aqueous solutions of zinc sulfate and sodium telluride. The films were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis and optical absorption measurement techniques. The synthesized ZnTe thin films were nanocrystalline with densely aggregated particles in nanometer scale and were free from the voids or cracks. The optical band gap energy of the film was found to be thickness dependent. The elemental chemical compositional stoichiometric analysis revealed good Zn:Te elemental ratio of 53:47.

  10. Preparation and characterization of ZnTe thin films by SILAR method

    Science.gov (United States)

    Kale, S. S.; Mane, R. S.; Pathan, H. M.; Shaikh, A. V.; Joo, Oh-Shim; Han, Sung-Hwan

    2007-02-01

    Nanocrystalline zinc telluride (ZnTe) thin films were prepared by using successive ionic layer adsorption and reaction (SILAR) method from aqueous solutions of zinc sulfate and sodium telluride. The films were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis and optical absorption measurement techniques. The synthesized ZnTe thin films were nanocrystalline with densely aggregated particles in nanometer scale and were free from the voids or cracks. The optical band gap energy of the film was found to be thickness dependent. The elemental chemical compositional stoichiometric analysis revealed good Zn:Te elemental ratio of 53:47.

  11. Thin Films with Low Zn Content Prepared by Chemical Bath Deposition

    Directory of Open Access Journals (Sweden)

    Caijuan Tian

    2012-01-01

    Full Text Available Chemical bath deposition (CBD was used for the growth of thin films with low Zn content. The influence of preparation conditions, such as pH, temperature, and concentration, on film properties was investigated. The chemical growth mechanism of thin films was analyzed, and optimized growth conditions for the thin films were established. The fill factor and short-circuit current were improved while was used to replace CdS as the window layer in CdTe solar cells.

  12. Studies on preparation and characterization of indium doped zinc oxide films by chemical spray deposition

    Indian Academy of Sciences (India)

    Benny Joseph; P K Manoj; V K Vaidyan

    2005-08-01

    The preparation of indium doped zinc oxide films is discussed. Variation of structural, electrical and optical properties of the films with zinc acetate concentration and indium concentration in the solution are investigated. XRD studies have shown a change in preferential orientation from (002) to (101) crystal plane with increase in indium dopant concentration. Films deposited at optimum conditions have a low resistivity of 1.33 × 10-4 m with 94% transmittance at 550 nm. SEM studies have shown smooth polycrystalline morphology of the films. Figure of merit is evaluated from electrical resistivity and transmittance data.

  13. Pharmaceutical films made from the waste material from the preparation of propolis extracts: development and characterization

    Directory of Open Access Journals (Sweden)

    Lucas de Alcântara Sica de Toledo

    2015-12-01

    Full Text Available abstract This study investigated the development and characterized the physicochemical properties of films obtained from by-products (BP from the preparation of propolis extracts. Films were produced in the presence and absence of a polymeric adjuvant (gelatin or ethylcellulose and propylene glycol by a solvent casting method. Density, surface topography by scanning electron microscopy, mechanical properties (folding endurance, tensile strength and percentage elongation, water vapour permeability (WVP, moisture uptake capacity, thermogravimetry, differential scanning calorimetry and Fourier transform infrared spectroscopy (FTIR were determined. The films were a transparent, light greenish-yellow colour, with a uniform surface, and were flexible and easy to handle. The thickness and density of the preparations indicated that the compounds were homogeneously dispersed throughout the film. Mechanical properties were influenced by the film composition; films containing gelatin were more resistant to stress, while those containing ethylcellulose were more flexible. Increasing the adjuvant concentration decreased the elasticity and the rupture resistance, but increased the moisture uptake capacity and WVP of the formulations. BP was thermally stable as were the films. FTIR tests suggested interactions between BP and the adjuvants. This work could contribute to the utilization of BP to prepare films for food and pharmaceutical uses

  14. Implications of total content of silicon, aluminium, chromium and formation of thin ferrite films on low ductility at high temperature in non oriented electrical steels

    Directory of Open Access Journals (Sweden)

    Equihua-Guillén, F.

    2011-10-01

    Full Text Available This work shows evidence of the implications of total additions of silicon, aluminium and chromium on low ductility during hot rolling in non-oriented electrical steels. This paper explains the reason of ductility loss at temperatures between 950 - 1000°C in electrical steels which exhibit higher Ar3 transformation temperature than C-Mn and microalloyed steels. The empirical equations to determine Ar3 temperature do not consider silicon and aluminium elements. The results show that high content of silicon, aluminium and residual concentration of chromiun considerably increases Ar3 transformation temperature in non-oriented electrical steels. The low ductility at high temperature occurs between Ae3 and Ar3 transformation temperatures. In addition, the results of this work show evidence of thin ferrite films formed near Ar3 temperature and their implications on ductility loss at high temperature.

    Este trabajo muestra evidencia de las implicaciones de la cantidad total de silicio, aluminio y cromo sobre la baja ductilidad en aceros eléctricos durante la laminación en caliente. Este artículo explica la razón de la pérdida de ductilidad a temperaturas entre 950 y 1.000°C en aceros eléctricos. Las ecuaciones empíricas para determinar la temperatura Ar3 no consideran los elementos aluminio y silicio. Los resultados muestran que altos contenidos de silicio, aluminio y la concentración residual de cromo incrementan considerablemente la temperatura de transformación Ar3 en aceros eléctricos de grano no orientado. La baja ductilidad a elevada temperatura ocurre entre las temperaturas de transformación Ae3 y Ar3. Adicionalmente, los resultados de este trabajo muestran evidencia de películas delgadas de ferrita formadas a temperaturas cercanas a Ar3 y sus implicaciones sobre la pérdida de

  15. Preparation of BiFeO3 thin films by pulsed laser deposition method

    Institute of Scientific and Technical Information of China (English)

    ZHANG Guan-jun; CHENG Jin-rong; CHEN Rui; YU Sheng-wen; MENG Zhong-yan

    2006-01-01

    BiFeO3 (BFO) thin films were prepared on Pt(111)/TiO2/SiO2/Si(100) substrates by the pulsed-laser deposition (PLD) technique at a low temperature of 450℃. The XRD results indicate that the BFO thin films are of perovskite structure with the presence of small amount of second phases. The oxygen pressures have great effect on the crystalline structures and dielectric properties of BFO thin films. The dielectric constant of the BFO thin films decreases with increasing oxygen pressures,achieving 186,171 and 160 at the frequency of 104 Hz for the oxygen pressures of 0.666,1.333 and 13.332 Pa,respectively. The BFO thin films prepared at the oxygen pressure of 0.666 Pa reveal a saturated hysteresis loop with the remanent polarization of 7.5 μC/cm2 and the coercive field of 176 kV/cm.

  16. PLD prepared nanostructured Pt-CeO2 thin films containing ionic platinum

    Science.gov (United States)

    Vorokhta, M.; Khalakhan, I.; Matolínová, I.; Nováková, J.; Haviar, S.; Lančok, J.; Novotný, M.; Yoshikawa, H.; Matolín, V.

    2017-02-01

    The composition of nanostructured Pt-CeO2 films on graphite substrates prepared by pulsed laser deposition has been investigated by means of hard X-ray photoelectron spectroscopy, scanning electron microscopy, high resolution transmission electron microscopy, and atomic force microscopy. The influence of morphology of the graphite substrates was investigated with respect to the relative concentrations of ionic and metallic Pt species in the films. It was found that the degree of Pt2+ enrichment is directly related to the surface morphology of graphite substrates. In particular, the deposition of Pt-CeO2 films on rough graphite substrate etched in oxygen plasma yielded nanostructured Pt-CeO2 catalyst films with high surface area and high Pt2+/Pt0 ratio. The presented results demonstrate that PLD is a suitable method for the preparation of thin Pt-CeO2 catalyst films for fuel cell applications.

  17. Composition, XRD and morphology study of laser prepared LiNbO{sub 3} films

    Energy Technology Data Exchange (ETDEWEB)

    Jelinek, M.; Remsa, J.; Kocourek, T. [Institute of Physics ASCR v.v.i., Prague 8 (Czech Republic); Czech Technical University in Prague, Faculty of Biomedical Engineering, Sitna, Kladno (Czech Republic); Havranek, V. [Nuclear Physics Institute ASCR, Rez near Prague (Czech Republic); Vincze, A.; Bruncko, J. [International Laser Centre, Bratislava 4 (Slovakia); Studnicka, V. [Institute of Physics ASCR v.v.i., Prague 8 (Czech Republic); Rubesova, K. [Institute of Chemical Technology, Prague 6 (Czech Republic)

    2013-03-15

    LiNbO{sub 3} films were deposited by PLD from LiNbO{sub 3} crystalline or from three different stoichiometric or Li-enriched LiNbO{sub 3} targets. Polycrystalline films were prepared on SiO{sub 2}/Si or sapphire substrates at temperatures T{sub S} {proportional_to}650-750 C. Main attention was paid to the influence of targets preparation and the deposition conditions on films composition, morphology and crystallinity. The thin-film morphology was determined by SEM microscopy. The composition was measured by SIMS, RBS, PIXE and PIGE methods. Highly oriented, smooth and stoichiometric LiNbO{sub 3} films were synthesized. (orig.)

  18. Preparation of Nano-Graphite Films and Field Emission Properties

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yong-Mei; ZHANG Bing-Lin; YAO Ning; LU Zhan-Ling; ZHANG Xin-Yue

    2004-01-01

    @@ Nano-graphite films have been deposited on n-Si substrates by microwave plasma chemical vapour deposition. The surface morphology and microstructure of the films were tested by scanning electron microscopy, x-ray diffraction and Raman spectroscopy. In the field emission measurement, a turn-on field of 0. 5 V/μm and a high emission-site density of 105/cm2 on a tested emission area of (34 × 35 mm2) have been obtained.

  19. A New Method for Preparing Superconducting MgB2 Films from Diborane

    Institute of Scientific and Technical Information of China (English)

    王殿生; 傅兴华; 张正平; 杨健

    2002-01-01

    We report on a new preparation method for magnesium diboride (MgB2) films by chemical vapour deposition(CVD) from diborane (B2H6). It is a two-step ex situ approach, with the precursor boron films grown by CVD from B2H6 at 460°C, followed by a post-annealing process in magnesium (Mg) vapour at 830°C. The prepared MgB2 thin films on Al2O3 polycrystalline substrates have an onset transition temperature of 35K and a zeroresistance temperature of about 24K. Well-crystallized MgB2 grains have clearly been observed in the SEM images and confirmed by x-ray diffraction analysis. The advantages of the proposed method are the feasibility to prepare large-area superconducting films and the compatibility with semiconductor technology.

  20. Property comparisons between NiZn ferrites prepared using NiO raw materials of different suppliers%采用不同厂家的NiO原料制备的NiZn铁氧体性能对比

    Institute of Scientific and Technical Information of China (English)

    聂敏; 徐方舟; 孙蒋平; 申志刚

    2011-01-01

    In this research, conventional oxide ceramic method was used to prepare NiZn ferrites, and the effect of NiO raw materials of different suppliers on the magnetic properties of corresponding materials was studied. The experimental results showed that the purity, particle size and surface morphology of NiO raw material seriously affect the reactivity and magnetic properties of the prepared materials. NiO raw material with high purity, homogeneous particle size and pinecone shape is the best choice for preparing high performance NiZn ferrite.%采用传统氧化物法制备NiZn铁氧体材料,考查不同厂家的NiO原料对于高性能NiZn铁氧体材料电磁性能的影响.实验表明,NiO原料的纯度、颗粒尺寸、颗粒形貌严重影响材料的烧结活性和电磁性能.高纯度、颗粒尺寸较均匀、形状为松果状的NiO原料是制备高性能NiZn铁氧体材料的最佳选择.

  1. Preparation and evaluation of thin-film sodium tungsten bronzes

    Science.gov (United States)

    Kautz, H. E.; Fielder, W. L.; Singer, J.; Fordyce, J. S.

    1974-01-01

    Thin films of sodium tungsten bronze (NaxWO3) were investigated as reversible sodium ion electrodes for solid electrolytes. The films were made by electron beam evaporation of the three phases, W metal, Na2WO4, and WO3, followed by sintering. The substrates were sodium beta alumina disks and glass slides. X-ray diffraction analyses of the films showed that sintering in dry nitrogen with prior exposure to air lead to mixed phases. Sintering in vacuum with no air exposure produced tetragonal I bronze with a nominal composition of Na0.31WO3, single phase within the limits of X-ray diffraction detectability. The films were uniform and adherent on sodium beta alumina substrates. The ac and dc conductivities of the beta alumina were measured with the sodium tungsten bronze films as electrodes. These experiments indicated that the tetragonal I bronze electrodes were not completely reversible. This may have resulted from sodium ion blocking within the bronze film or at the bronze beta alumina interface. Methods for attempting to make more completely reversible electrodes are suggested.

  2. Methods for preparing colloidal nanocrystal-based thin films

    Energy Technology Data Exchange (ETDEWEB)

    Kagan, Cherie R.; Fafarman, Aaron T.; Choi, Ji-Hyuk; Koh, Weon-kyu; Kim, David K.; Oh, Soong Ju; Lai, Yuming; Hong, Sung-Hoon; Saudari, Sangameshwar Rao; Murray, Christopher B.

    2016-05-10

    Methods of exchanging ligands to form colloidal nanocrystals (NCs) with chalcogenocyanate (xCN)-based ligands and apparatuses using the same are disclosed. The ligands may be exchanged by assembling NCs into a thin film and immersing the thin film in a solution containing xCN-based ligands. The ligands may also be exchanged by mixing a xCN-based solution with a dispersion of NCs, flocculating the mixture, centrifuging the mixture, discarding the supernatant, adding a solvent to the pellet, and dispersing the solvent and pellet to form dispersed NCs with exchanged xCN-ligands. The NCs with xCN-based ligands may be used to form thin film devices and/or other electronic, optoelectronic, and photonic devices. Devices comprising nanocrystal-based thin films and methods for forming such devices are also disclosed. These devices may be constructed by depositing NCs on to a substrate to form an NC thin film and then doping the thin film by evaporation and thermal diffusion.

  3. High-mobility ultrathin semiconducting films prepared by spin coating.

    Science.gov (United States)

    Mitzi, David B; Kosbar, Laura L; Murray, Conal E; Copel, Matthew; Afzali, Ali

    2004-03-18

    The ability to deposit and tailor reliable semiconducting films (with a particular recent emphasis on ultrathin systems) is indispensable for contemporary solid-state electronics. The search for thin-film semiconductors that provide simultaneously high carrier mobility and convenient solution-based deposition is also an important research direction, with the resulting expectations of new technologies (such as flexible or wearable computers, large-area high-resolution displays and electronic paper) and lower-cost device fabrication. Here we demonstrate a technique for spin coating ultrathin (approximately 50 A), crystalline and continuous metal chalcogenide films, based on the low-temperature decomposition of highly soluble hydrazinium precursors. We fabricate thin-film field-effect transistors (TFTs) based on semiconducting SnS(2-x)Se(x) films, which exhibit n-type transport, large current densities (>10(5) A cm(-2)) and mobilities greater than 10 cm2 V(-1) s(-1)--an order of magnitude higher than previously reported values for spin-coated semiconductors. The spin-coating technique is expected to be applicable to a range of metal chalcogenides, particularly those based on main group metals, as well as for the fabrication of a variety of thin-film-based devices (for example, solar cells, thermoelectrics and memory devices).

  4. Preparation and characterisation of fluconazole vaginal films for the treatment of vaginal Candidiasis

    Directory of Open Access Journals (Sweden)

    L Kumar

    2013-01-01

    Full Text Available Objective of the present study was to develop and evaluate vaginal films with essential in vitro studies. Films were developed using hydroxypropyl methylcellulose as a polymer and formulations were coded. The developed films were evaluated with Fourier transform infrared spectroscopy, drug content, viscosity, surface pH, thickness, mechanical characterisation and in vitro drug release study. Fourier transform infrared spectroscopy results confirmed that there is no chemical interaction between drug and stabilisers/excipients. The batch variation was not more than 5% for average thickness and weight of the films. The drug content for the prepared formulation was in the range of 72.32±0.18% to 94.48±0.54%. Viscosity of the formulations increased with the increase in concentration of polymer. Mechanical characterisation revealed that tensile strength and percentage elongation of the films improved as there is increase in degree of substitution of the polymer, but the values of modulus decreased which confirmed that all the prepared films are soft in nature. The in vitro study indicated that 1 and 2% concentrations of polymer are the least concentrations to control the release of drug whereas the 4% concentration of polymer is a good and more effective concentration to control the release. Only one prepared formulation released the drug by following anomalous transport whereas other film formulations released the fluconazole by following Fickian diffusion mechanism. Prepared vaginal films may be an important alternative for the treatment of vaginal candidiasis, because these prepared films suggest the benefits of controlled release of fluconazole at the site of absorption.

  5. Preparation of CoP films by ultrasonic electroless deposition at low initial temperature

    Institute of Scientific and Technical Information of China (English)

    Yundan Yu; Zhenlun Song; Hongliang Ge; Guoying Wei

    2014-01-01

    Electroless deposition technology has been considered as a kind of common ways to obtain cobalt alloy films. However, in order to get cobalt alloy films, high temperature (353 K) is necessary during the electroless deposition process which will increase costs and energy consumption. Ultrasonic was introduced during electroless plating process to obtain cobalt alloy films at lower initial temperature. It was found that the cobalt thin films could be prepared at lower initial temperature (323 K) with the introduction of ultrasonic. Therefore, different powers of ultrasonic were applied during the electroless deposition process to prepare CoP thin films on copper substrates from an alkaline bath in this investigation. The effects of different powers of ultrasonic on deposition rate, surface morphology, anticorrosion performance and magnetic property of films were studied. It was found that the deposition rate increased gradually with the rise in ultrasonic powers due to cavitation phenomenon. All the CoP films presented the typical spherical nodular structures with the impact of ultrasonic. Smaller and regular shaped structures could be observed when the films were deposited with higher power of ultrasonic which contributed directly to enhancement of anticorrosion performance. Saturation magnetization and coercivity of thin films increased gradually with the rise in ultrasonic powers during the electroless deposition process due to the higher amounts of cobalt.

  6. Preparation and characterization of osmium hexacyanoferrate films and their electrocatalytic properties

    Energy Technology Data Exchange (ETDEWEB)

    Chen, S.-M. [Department of Chemical Engineering, National Taipei University of Technology, No. 1, Section 3, Chung-Hsiao East Road, Taipei, Taiwan 106 (China)]. E-mail: smchen78@ms15.hinet.net; Liao, C.-J. [Department of Chemical Engineering, National Taipei University of Technology, No. 1, Section 3, Chung-Hsiao East Road, Taipei, Taiwan 106 (China)

    2004-11-15

    Osmium hexacyanoferrate films have been prepared using repeated cyclic voltammetry, and the deposition process and the films' electrocatalytic properties in electrolytes containing various cations have been investigated. The cyclic voltammograms recorded the deposition of osmium hexacyanoferrate films directly from the mixing of Os{sup 3+} and Fe(CN){sub 6}{sup 3-} ions from solutions containing various cations. An electrochemical quartz crystal microbalance, cyclic voltammetry, and UV-visible spectroscopy were used to study the growth mechanism of the osmium hexacyanoferrate films. The osmium hexacyanoferrate films showed a single redox couple, and the redox reactions included 'electron transfer' and 'proton transfer' with a formal potential that demonstrates a proton effect in acidic solutions up to a 12 M aqueous HCl solution. The electrochemical and electrochemical quartz crystal microbalance results indicate that the redox process was confined to the immobilized osmium hexacyanoferrate film. The electrocatalytic reduction of dopamine, epinephrine, norepinephrine, S{sub 2}O{sub 3}{sup 2-}, and SO{sub 5}{sup 2-} by the osmium hexacyanoferrate films was performed. The preparation and electrochemical properties of co-deposited osmium(III) hexacyanoferrate and copper(II) hexacyanoferrate films were determined, and their two redox couples showed formal potentials that demonstrated a proton effect and an alkaline cation effect, respectively. Electrocatalytic reactions on the hybrid films were also investigated.

  7. CdS thin films prepared by laser assisted chemical bath deposition

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, L.V.; Mendivil, M.I.; Garcia Guillen, G.; Aguilar Martinez, J.A. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, Av. Pedro de Alba s/n, Ciudad Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico); Krishnan, B. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, Av. Pedro de Alba s/n, Ciudad Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico); CIIDIT – Universidad Autonoma de Nuevo Leon, Apodaca, Nuevo Leon (Mexico); Avellaneda, D.; Castillo, G.A.; Das Roy, T.K. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, Av. Pedro de Alba s/n, Ciudad Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico); Shaji, S., E-mail: sshajis@yahoo.com [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, Av. Pedro de Alba s/n, Ciudad Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico); CIIDIT – Universidad Autonoma de Nuevo Leon, Apodaca, Nuevo Leon (Mexico)

    2015-05-01

    Highlights: • CdS thin films by conventional CBD and laser assisted CBD. • Characterized these films using XRD, XPS, AFM, optical and electrical measurements. • Accelerated growth was observed in the laser assisted CBD process. • Improved dark conductivity and good photocurrent response for the LACBD CdS. - Abstract: In this work, we report the preparation and characterization of CdS thin films by laser assisted chemical bath deposition (LACBD). CdS thin films were prepared from a chemical bath containing cadmium chloride, triethanolamine, ammonium hydroxide and thiourea under various deposition conditions. The thin films were deposited by in situ irradiation of the bath using a continuous laser of wavelength 532 nm, varying the power density. The thin films obtained during deposition of 10, 20 and 30 min were analyzed. The changes in morphology, structure, composition, optical and electrical properties of the CdS thin films due to in situ irradiation of the bath were analyzed by atomic force microscopy (AFM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV–vis spectroscopy. The thin films obtained by LACBD were nanocrystalline, photoconductive and presented interesting morphologies. The results showed that LACBD is an effective synthesis technique to obtain nanocrystalline CdS thin films having good optoelectronic properties.

  8. Studies of thin films of Ti- Zr -V as non-evaporable getter films prepared by RF sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Nidhi; Jagannath,; Sharma, R. K.; Gadkari, S. C.; Muthe, K. P.; Mukundhan, R.; Gupta, S. K. [Technical Physics Division, BARC Mumbai-400085 (India)

    2013-02-05

    Non-Evaporable Getter (NEG) films of the Ti-Zr-V prepared on stainless steel substrates by Radio Frequency sputtering. To observe its getter behavior at the lowest activation temperature, the sample is heated continuously at different temperatures (100 Degree-Sign C, 150 Degree-Sign C, 200 Degree-Sign C and 250 Degree-Sign C) for 2 hours. The changes of the surface chemical composition at different temperaturesare analyzed by using XPS and SEM (Scanning Electron Microscopy) techniques. The volume elemental composition of the film has been measured by energy dispersive X-ray spectroscopy (EDX). The in-situ XPS measurements of the activated getter films show the disappearance of the superficial oxide layer through the variation in the oxygen stoichiometry during thermal activation. Results of these studies show that the deposited films of Ti-Zr-V could be used as NEG to produce extreme high vacuum.

  9. Structural investigation of an extended milled ferrite powder

    Energy Technology Data Exchange (ETDEWEB)

    Moisin, A.M.; Macrin, M. (Institutul de Cercetari Electronice, Bucharest (Romania))

    1980-01-01

    An investigation of the structural modifications introduced by the extended milling and annealing processes in the barium ferrite powder during its preparation is presented. X-ray diffraction measuements on a barium ferrite powder in various milling and annealing conditions have been carried out and the results concerning the phase compositions, lattice constants and crystallite sizes are discussed.

  10. Microstructure and magnetic properties of MFe{sub 2}O{sub 4} (M = Co, Ni, and Mn) ferrite nanocrystals prepared using colloid mill and hydrothermal method

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wei, E-mail: wangwei@mail.buct.edu.cn; Ding, Zui; Zhao, Xiruo [State Key Laboratory of Chemical Resource Engineering and School of Science, Beijing University of Chemical Technology, Beijing 100029 (China); Beijing Key Laboratory of Environmentally Harmful Chemical Analysis, Beijing University of Chemical Technology, Beijing 100029 (China); Wu, Sizhu [State Key Laboratory of Organic–Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China); Li, Feng [State Key Laboratory of Chemical Resource Engineering and School of Science, Beijing University of Chemical Technology, Beijing 100029 (China); Yue, Ming [College of Materials Science and Engineering, Beijing University of Technology, Beijing 100022 (China); Liu, J. Ping [Department of Physics, University of Texas at Arlington, Arlington, Texas 76019 (United States)

    2015-05-07

    Three kinds of spinel ferrite nanocrystals, MFe{sub 2}O{sub 4} (M = Co, Ni, and Mn), are synthesized using colloid mill and hydrothermal method. During the synthesis process, a rapid mixing and reduction of cations with sodium borohydride (NaBH{sub 4}) take place in a colloid mill then through a hydrothermal reaction, a slow oxidation and structural transformation of the spinel ferrite nanocrystals occur. The phase purity and crystal lattice parameters are estimated by X-ray diffraction studies. Scanning electron microscopy and transmission electron microscopy images show the morphology and particle size of the as-synthesized ferrite nanocrystals. Raman spectrum reveals active phonon modes at room temperature, and a shifting of the modes implies cation redistribution in the tetrahedral and octahedral sites. Magnetic measurements show that all the obtained samples exhibit higher saturation magnetization (M{sub s}). Meanwhile, experiments demonstrate that the hydrothermal reaction time has significant effects on microstructure, morphologies, and magnetic properties of the as-synthesized ferrite nanocrystals.

  11. The comparative study of the structural and the electrical properties of the nano spinel ferrites prepared by the soft mehanochemical synthesis

    Directory of Open Access Journals (Sweden)

    Sekulić D.L.

    2014-01-01

    Full Text Available Nano spinel ferrites MFe2O4 (M=Ni, Mn, Zn were obtained by soft mechanochemical synthesis in a planetary ball mill. The appropriate mixture of oxide and hydroxide powders was used as initial compounds. All of this mixture of powders was mechanically activated, uniaxial pressed and sintered at 1100°C/2h. The phase composition of the powders and sintered samples were analyzed by XRD and Raman spectroscopy. Morphologies were examined by SEM. In this study, the AC-conductivity and DC-resistivity of sintered samples of MFe2O4 (M= Ni, Mn, Zn ferrites were measured at different frequencies and at room temperature. The values of the electrical conductivities show an increase with increasing temperature, which indicated the semiconducting behavior of the studied ferrites. The conduction phenomenon of the investigated samples could be explained on the basis of hopping model. The complex impedance spectroscopy analysis was used to study the effect of grain and grain boundary on the electrical properties of all three obtained ferrites [Projekat Ministarstva nauke Republike Srbije, br. III 45003

  12. Preparation and characterization of biodegradable active PLA film for food packaging

    Science.gov (United States)

    Di Maio, L.; Scarfato, P.; Avallone, E.; Galdi, M. R.; Incarnato, L.

    2014-05-01

    In this work we report on the preparation and characterization of a biodegradable active PLA film (aPLA), intended for food packaging applications. The film was obtained by cast extrusion blending a commercial PLA matrix with an active system, developed in our laboratory and based on PLA microparticles containing a-tocopherol (aTCP) as natural antioxidant agent. In order to optimize the film composition and processing, the active microparticles were preliminarily characterized with the aim to evaluate their morphology (size and shape), thermal resistance and a-tocopherol content. The aPLA film, produced with a 5wt% of aTCP, was characterized in terms of performance and activity. The experimental results demonstrated that the aPLA film has mechanical, thermal, barrier and optical properties adequate for packaging applications and shows oxygen scavenging activity and prolonged exhaustion lag time, compared to pure PLA films.

  13. Preparation and Characterization of Polyvinylidene Fluoride/Graphene Superhydrophobic Fibrous Films

    Directory of Open Access Journals (Sweden)

    Rasoul Moradi

    2015-08-01

    Full Text Available A new strategy to induce superhydrophobicity via introducing hierarchical structure into the polyvinylidene fluoride (PVDF film was explored in this study. For this purpose nanofibrous composite films were prepared by electrospinning of PVDF and PVDF/graphene blend solution as the main precursors to produce a net-like structure. Various spectroscopy and microscopy methods in combination with crystallographic and wettability tests were used to evaluate the characteristics of the synthesized films. Mechanical properties have been studied using a universal stress-strain test. The results show that the properties of the PVDF nanofibrous film are improved by compositing with graphene. The incorporation of graphene flakes into the fibrous polymer matrix changes the morphology, enhances the surface roughness, and improves the hydrophobicity by inducing a morphological hierarchy. Superhydrophobicity with the water contact angle of about 160° can be achieved for the PVDF/graphene electrospun nanocomposite film in comparison to PVDF pristine film.

  14. Preparation of TiO2 Thin Film and Its Antibacterial Activity

    Institute of Scientific and Technical Information of China (English)

    XU Wei-guo; CHEN An-min; ZHANG Qiang

    2004-01-01

    TiO2 nanometer thin films with photocatalytic antibacterial activity were prepared by the sol-gelmethod on fused quartz and soda lime glass precoated with a SiO2 layer. The thin films were characterized by X-ray photoelectron spectroscopy ( XPS ), scanning electron microscopy (SEM), and X- ray diffraction ( XRD ). Theresults show that sodium and calcium diffusion into nascent TiO2 film is effectively retarded by the SiO2 layer pre-coated on the soda lime glass. The antibacterial activity of the films was determined. The crystalline of TiO2 nano-meter thin film has important effects on the antibacterial activity of the film.

  15. Preparation and Properties of Ag-TiO2 Thin Films on Glass Substrates

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Ag-TiO2 thin films were prepared on glasses.The morphology and structure of Ag-TiO2 films were investigated by XRD, SEM and FT-IR.The photocatalytic and hydrophilic properties of Ag-TiO2 thin films were also evaluated by examining photocatalytic degradation dichlorophos under sunlight illumination and the change of contact angle respectively.The research results show that the Ag-TiO2 thin film is mainly composed of 20-100nm Ag and TiO2 particles.The Ag-TiO2 thin films possess a super-hydrophilic ability and higher photocatalytic activity than that of pure TiO2 thin film.

  16. Effect of Soft-annealing on the Properties of CIGSe Thin Films Prepared from Solution Precursors

    Energy Technology Data Exchange (ETDEWEB)

    Sung, Shijoon; Park, Misun; Kim, Daehwan; Kang, Jinkyu [Daegu Gyeongbuk Institute of Science and Technology, Daegu (Korea, Republic of)

    2013-05-15

    Solution-based deposition of CuIn{sub x}Ga{sub 1-x}Se{sub 2} (CIGSe) thin films is well known non-vacuum process for the fabrication of CIGSe solar cells. However, due to the usage of organic chemicals in the preparation of CIG precursor solutions, the crystallization of the polycrystalline CIGSe and the performance of CIGSe thin film solar cells were significantly affected by the carbon residues from the organic chemicals. In this work, we have tried to eliminate the carbon residues in the CIG precursor thin films efficiently by using soft-annealing process. By adjusting soft-annealing temperature, it is possible to control the amount of carbon residues in CIG precursor thin films. The reduction of the carbon residues in CIG precursors by high temperature soft-annealing improves the grain size and morphology of polycrystalline CIGSe thin films, which are also closely related with the electrical properties of CIGSe thin film solar cells.

  17. Preparation and characterization of nanostructured CuO thin films for photoelectrochemical splitting of water

    Indian Academy of Sciences (India)

    Diwakar Chauhan; V R Satsangi; Sahab Dass; Rohit Shrivastav

    2006-12-01

    Nanostructured copper oxide thin films (CuO) were prepared on conducting glass support (SnO2: F overlayer) via sol–gel starting from colloidal solution of copper (II) acetate in ethanol. Films were obtained by dip coating under room conditions (temperature, 25–32°C) and were subsequently sintered in air at different temperatures (400–650°C). The evolution of oxide coatings under thermal treatment was studied by glancing incidence X-ray diffraction and scanning electron microscopy. Average particle size, resistivity and band gap energy were also determined. Photoelectrochemical properties of thin films and their suitability for splitting of water were investigated. Study suggests that thin films of CuO sintered at lower temperatures (≈ 400°C) are better for photoconversion than thick films or the films sintered at much higher temperatures. Plausible explanations have been provided.

  18. Preparation and characterization of GaN films grown on Ga-diffused Si(111) substrates

    Institute of Scientific and Technical Information of China (English)

    SUN Zhencui; CAO Wentian; WEI Qinqin; WANG Shuyun; XUE Chengshan; SUN Haibo

    2005-01-01

    Hexagonal GaN films were prepared by nitriding Ga2O3 films with flowing ammonia. Ga2O3 films were deposited on Ga-diffused Si (111) substrates by radio frequency (r.f.) magnetron sputtering. This paper have investigated the change of structural properties of GaN films nitrided in NH3 atmosphere at the temperatures of 850, 900, and 950℃ for 15min and nitrided at the temperature of 900℃ for 10, 15, and 20 min, respectively. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) were used to analyze the structure, surface morphology and composition of synthesized samples. The results reveal that the as-grown films are polycrystalline GaN with hexagonal wurtzite structure and GaN films with the highest crystal quality can be obtained when nitrided at 900℃ for 15 min.

  19. Preparation and Characterization of Chitosan/Agar Blended Films: Part 2. Thermal, Mechanical, and Surface Properties

    Directory of Open Access Journals (Sweden)

    Esam A. Elhefian

    2012-01-01

    Full Text Available Chitosan/agar (CS/AG films were prepared by blending different proportions of chitosan and agar (considering chitosan as the major component in solution forms. The thermal stability of the blended films was studied using thermal gravimetric analysis (TGA. It was revealed that chitosan and agar form a compatible blend. Studying the mechanical properties of the films showed a decrease in the tensile strength and elongation at break with increasing agar content. Blending of agar with chitosan at all proportions was found to form hydrogel films with enhanced swelling compared to the pure chitosan one. Static water contact angle measurements confirmed the increasing affinity of the blended films towards water suggesting that blending of agar with chitosan improves the wettability of the obtained films.

  20. Dielectric dilatometry on thin Teflon-PTFE films prepared by pulsed-laser deposition

    Science.gov (United States)

    Schwoediauer, Reinhard; Bauer-Gogonea, Simona; Bauer, Stefan; Heitz, J.; Arenholz, Enno; Baeuerle, Dieter

    1999-12-01

    Polytetrafluoroethylene (Teflon PTFE) films were grown by pulsed-laser deposition (PLD). Films prepared by ablation from press-sintered targets are found to be highly crystalline, with spherulite sizes adjustable over more than one order in magnitude by suitable thermal annealing. As revealed by dielectric dilatometry, PLD-PTFE films show characteristics remarkably similar to those of conventional PTFE, i.e. the same structural first-order phase transitions. Dielectric losses are low and indicate no tendency to film oxidation. PLD-PTFE films additionally show an excellent charge-stability, comparable and even superior to commercially available Teflon-PTFE foils. PLD-PTFE enlarges the family of Teflon materials and may thus become interesting for potential miniaturized electret devices. Furthermore, dielectric dilatometry provides an elegant means for the determination of the coefficient of thermal expansion in thin nonpolar films.

  1. Characteristics of W Doped Nanocrystalline Carbon Films Prepared by Unbalanced Magnetron Sputtering.

    Science.gov (United States)

    Park, Yong Seob; Park, Chul Min; Kim, Nam-Hoon; Kim, Jae-Moon

    2016-05-01

    Nanocrystalline tungsten doped carbon (WC) films were prepared by unbalanced magnetron sputtering. Tungsten was used as the doping material in carbon thin films with the aim of application as a contact strip in an electric railway. The structural, physical, and electrical properties of the fabricated WC films with various DC bias voltages were investigated. The films had a uniform and smooth surface. Hardness and frication characteristics of the films were improved, and the resistivity and sheet resistance decreased with increasing negative DC bias voltage. These results are associated with the nanocrystalline WC phase and sp(2) clusters in carbon networks increased by ion bombardment enhanced with increasing DC bias voltage. Consequently, the increase of sp(2) clusters containing WC nanocrystalline in the carbon films is attributed to the improvement in the physical and electrical properties.

  2. Preparation and characterization of DC sputtered molybdenum thin films

    Directory of Open Access Journals (Sweden)

    Abd El-Hady B. Kashyout

    2011-03-01

    Full Text Available Molybdenum (Mo thin films have been deposited on soda-lime glass substrates using a DC magnetron sputtering system. Their electrical resistivity, and their morphological, structural and adhesive properties have been examined with respect to the deposition power, deposition time and substrate temperature. The electrical resistivity of the Mo films could be reduced by increasing any of the above parameters. Within the range of the investigated deposition parameters, the films showed a mono-crystalline nature with a preferred orientation along the (1 1 0 plane. The Mo films adhesion to the soda-lime glass could be improved by increasing the substrate temperature. At a deposition power of 200 W, deposition time of 20 min and substrate temperature of 450 °C, Mo thin film exhibiting mono-crystalline structure with thickness equal to 450 nm and electrical resistivity equal to 1.85 × 10−4 Ω cm was obtained.

  3. High index of refraction films for dielectric mirrors prepared by metal-organic chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Brusasco, R.M.

    1989-01-01

    A wide variety of metal oxides with high index of refraction can be prepared by Metal-Organic Chemical Vapor Deposition. We present some recent optical and laser damage results on oxide films prepared by MOCVD which could be used in a multilayer structure for highly reflecting (HR) dielectric mirror applications. The method of preparation affects both optical properties and laser damage threshold. 10 refs., 8 figs., 4 tabs.

  4. GaAs Films Prepared by RF-Magnetron Sputtering

    Energy Technology Data Exchange (ETDEWEB)

    L.H. Ouyang; D.L. Rode; T. Zulkifli; B. Abraham-Shrauner; N. Lewis; M.R. Freeman

    2001-08-01

    The authors reported on the optical absorption, adhesion, and microstructure of RF-magnetron sputtered films of hydrogenated amorphous and microcrystalline GaAs films for the 1 to 25 {micro}m infrared wavelength rate. Sputtering parameters which were varied include sputtering power, temperature and pressure, and hydrogen sputtering-gas concentration. TEM results show a sharp transition from purely amorphous GaAs to a mixture of microcrystalline GaAs in an amorphous matrix at 34 {+-} 2 C. By optimizing the sputtering parameters, the optical absorption coefficient can be decreased below 100 cm{sup -1} for wavelengths greater than about 1.25 {micro}m. These results represent the lowest reported values of optical absorption for sputtered films of GaAs directly measured by spectrophotometry for the near-infrared wavelength region.

  5. Standard Operating Procedure for the Preparation of Lead-Containing Paint Films and Lead-in-Paint Diagnostic Test Materials

    Science.gov (United States)

    This SOP describes the preparation of stand-alone, lead paint films, prepared according to the old paint recipes. Further, this SOP describes the use of these paint films for the preparation of simulated old paints on a variety of substrates. Substrates used included wood, stee...

  6. Preparation and characterization of highly photosensitive ZnO thin films

    Science.gov (United States)

    Jiménez González, Antonio E.; Nair, P. K.

    1996-07-01

    Highly photosensitive ZnO films were prepared by the chemical technique Successive Ion Layer Adsorption and Reaction (SILAR). The films posses high optical transmittance (>90%) in the VIS and IR ranges. The cristallinity, orientation of the crystallites and surface morphology undergo changes with annealing. The optical transmittance and reflectance measurements indicated changes in the position of the optical absorption edge: shifting from 353 nm to 366 nm when annealed at 450 °C for 2 hours. The films are highly photosensitive, offering photocurrent to dark current ratio of 105, in as prepared films under 900 Wm-2 illumination from a solar simulator. Annealing in oxygen, hydrogen and vacuum improved the dark conductivity and the photoconductivity of the films. This effect is related to the modification of the defect statistics of the films and involves cation interstitials and anion vacancies. The studies indicate that the ZnO films prepared by the SILAR process may be used, with appropriated postdeposition treatments, for specific applications.

  7. Preparation of conductive PDDA/(PEDOT:PSS) multilayer thin film: influence of polyelectrolyte solution composition.

    Science.gov (United States)

    Jurin, F E; Buron, C C; Martin, N; Filiâtre, C

    2014-10-01

    Self-assembled multilayer films made of PEDOT:PSS poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) and PDDA poly(diallyldimethylammonium chloride) were prepared using layer-by-layer method. In order to modify the growth regime of the multilayer, to fabricate an electrical conductive film and to control its thickness, the effects of pH, type of electrolyte, ionic strength and polyelectrolyte concentration were investigated. Optical reflectometry measurements show that the pH of the solutions has no effect on the film growth while the adsorbed amount increases more rapidly when BaCl2 is used instead of NaCl as electrolyte. An increase in the ionic strength (with NaCl) induces a change in the growth regime from a linear to an exponential one at low polyelectrolyte concentration. As UV-vis measurements indicate, no decomplexation of PEDOT was recorded after film preparation. With polyelectrolyte concentration below 1 g L(-1), no conductive films were obtained even if 50 bilayers were deposited. A conductive film was prepared with a polyelectrolyte concentration of 1 g L(-1) and the measured conductivity was 0.3 S m(-1). A slight increase in conductivity was recorded when BaCl2 was used probably due to a modification of the film structure. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. [Research on the polycrystalline CdS thin films prepared by close-spaced sublimation].

    Science.gov (United States)

    Yang, Ding-Yu; Xia, Geng-Pei; Zheng, Jia-Gui; Feng, Liang-Huan; Cai, Ya-Ping

    2009-01-01

    In the present paper, the factors of influence on the deposition rate of CdS films prepared by close-spaced sublimation (CSS) were first studied systematically, and it was found from the experiments that the deposition rate increased with the raised temperature of sublimation source, while decreased with the raised substrate temperature and the deposition pressure. The structure, morphology and light transmittance of the prepared samples were tested subsequently, and the results show: (1) The CdS films deposited under different oxygen partial pressure all present predominating growth lattice orientation (103), and further more the films will be strengthened after annealed under CdCl2 atmosphere. (2) The AFM images of CdS show that the films are compact and uniform in grain diameter, and the grain size becomes larger with the increased substrate temperature. Along with it, the film roughness was also augmented. (3) The transmittance in the shortwave region of visible light through the CdS films would be enhanced when its thickness is reduced, and that will help improve the shortwave spectral response of CdTe solar cells. Finally, the prepared CdS films were employed to fabricate CdTe solar cells, which have achieved a conversion efficiency of 10.29%, and thus the feasibility of CSS process in the manufacture of CdTe solar cells was validated primarily.

  9. Effect of annealing on phase transition in poly(vinylidene fluoride) films prepared using polar solvent

    Indian Academy of Sciences (India)

    S Satapathy; Santosh Pawar; P K Gupta; K B R Varma

    2011-07-01

    The -phase poly (vinylidene fluoride) (PVDF) films are usually prepared using dimethyl sulfoxide (DMSO) solvent, regardless of preparation temperature. Here we report the crystallization of both and -phase PVDF films by varying preparation temperature using DMSO solvent. The -phase PVDF films were annealed at 70, 90, 110, 130 and 160°C for five hours. The changes in the phase contents in the PVDF at different annealing conditions have been described. When thin films were annealed at 90°C for 5 h, maximum percentage of -phase appears in PVDF thin films. The -phase PVDF films completely converted to -phase when they were annealed at 160°C for 5 h. From X-ray diffraction (XRD), Fourier transform infrared spectrum (FTIR), differential scanning calorimetry (DSC) and Raman studies, it is confirmed that the PVDF thin films, cast from solution and annealed at 90°C for 5 h, have maximum percentage of -phase. The -phase PVDF shows a remnant polarization of 4.9 C/cm2 at 1400 kV/cm at 1 Hz.

  10. Latest progress of low temperature sintering ferrite powder%发展我国电子元件工业的思路

    Institute of Scientific and Technical Information of China (English)

    李盛涛; 李建英; 张伟强

    2001-01-01

    The progress of low temperature sintering ferrite powder are reviewed on the basis of the major projects under The State 863 Plan and the important theses of The 8th International Conference on Ferrite. NiCuZn ferrite, MgCuZn ferrite and hexagonal crystal system Co2Z ferrite prepared by solid phase reaction are presented. And the achievement of newly developed NicuZu ferrite and hexagonal crystal system Co2Z ferrite prepared by soft chemical technique are reported.(14 refs.)

  11. Ferroelectric-Like Properties of Amorphous Metal Oxide Thin Films Prepared by Sol-Gel Technique.

    Science.gov (United States)

    Xu, Yuhuan

    1995-01-01

    Advances in the field of both optical and electrical integrated circuit devices require new thin film materials. Ferroelectric materials have attractive properties such as hysteresis behavior, pyroelectricity, piezoelectricity and nonlinear optical properties. Many ferroelectric thin films have been successfully prepared from metal organic compounds via sol-gel processing. Thus far, research has concentrated upon polycrystalline or epitaxial ferroelectric films. For amorphous ferroelectric thin films, preliminary experimental results in our laboratory indicated that these amorphous films possessed good ferroelectric -like properties. The purpose of this research is (1) to fabricate amorphous metal oxide thin films by the sol-gel technique, (2) to determine whether these amorphous metal oxide thin films have ferroelectric-like properties and (3) to propose a theoretical model ("ferrons model") to explain the ferroelectric-like properties of amorphous thin films, which deals with a structure of permanent dipoles of "partially ordered clusters" (ferrons) in the amorphous films. The theoretical model is based on our experimental results of thin films of two amorphous materials (barium titanite and lead zirconate titanate). This research may provide a new functional material which could be useful for producing integrated electronic and electrooptic devices.

  12. Characterization of sol-gel-prepared Ti02 thin film for O2 sensing

    Science.gov (United States)

    Atashbar, Massood Z.; Ghantasala, Muralihar K.; Wlodarski, Wojtek

    1997-11-01

    This paper presents the results of our investigation on deposition and characterization of sol-gel prepared TiO2 thin films for oxygen sensing applications. The properties of pure TiO2 thin films are compared with those doped with niobium oxide and 1%pt. These films are characterized using Rutherford backscattering spectroscopy (RBS), x-ray diffraction (XRD) and scanning electron microscopy (SEM) to study their chemical composition, structure and surface morphology respectively. Both kinds of the films are stoichiometric. Pure TiO2 as well as doped films were amorphous as deposited. Pure TiO2 films after annealing to 450 degrees Celsius and above showed the formation of anatase phase, while the doped films still predominantly amorphous, barely showing the onset of crystallinity. Pure films after annealing to 600 degrees Celsius appear to have become granular and porous. Doping with niobium oxide and Pt resulted in modification of film microstructure also. As a result of doping, the gas sensitivity of the films is increased from 8 to 24 and operating temperature decreased from 320 degrees Celsius to 190 degrees Celsius.

  13. Characterisation of Pb thin films prepared by the nanosecond pulsed laser deposition technique for photocathode application

    Energy Technology Data Exchange (ETDEWEB)

    Lorusso, A., E-mail: antonella.lorusso@le.infn.it [Dipartimento di Matematica e Fisica “E. De Giorgi” and Istituto Nazionale di Fisica Nucleare, Università del Salento, Lecce 73100 (Italy); Gontad, F. [Dipartimento di Matematica e Fisica “E. De Giorgi” and Istituto Nazionale di Fisica Nucleare, Università del Salento, Lecce 73100 (Italy); Broitman, E. [Department of Physics, Chemistry and Biology (IFM), Linköping University, Linköping SE-581 83 (Sweden); Chiadroni, E. [Laboratori Nazionali di Frascati, Istituto Nazionale di Fisica Nucleare, Frascati 00044 (Italy); Perrone, A. [Dipartimento di Matematica e Fisica “E. De Giorgi” and Istituto Nazionale di Fisica Nucleare, Università del Salento, Lecce 73100 (Italy)

    2015-03-31

    Pb thin films were prepared by the nanosecond pulsed laser deposition technique on Si (100) and polycrystalline Nb substrates for photocathode application. As the photoemission performances of a cathode are strongly affected by its surface characteristics, the Pb films were grown at different substrate temperatures with the aim of modifying the morphology and structure of thin films. An evident morphological modification in the deposited films with the formation of spherical grains at higher temperatures has been observed. X-ray diffraction measurements showed that a preferred orientation of Pb (111) normal to the substrate was achieved at 30 °C while the Pb (200) plane became strongly pronounced with the increase in the substrate temperature. Finally, a Pb thin film deposited on Nb substrate at 30 °C and tested as the photocathode showed interesting results for the application of such a device in superconducting radio frequency guns. - Highlights: • Pb thin films obtained by the nanosecond pulsed laser deposition technique at different substrate temperature. • The substrate temperature modifies the morphology and structure of Pb films. • Pb thin film was deposited at room temperature for photocathode application. • The Pb thin film photocathode was tested and the quantum efficiency of the device improved after laser cleaning treatment of the film surface.

  14. Preparation and Performance of Rare Earths Chemical Conversion Film on Magnesium Alloy

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Golden yellow cerium conversion film was obtained on magnesium alloys surface by immersion method and the preparation parameters were established. The influence of different process parameters on the surface morphology and performance of the conversion film were analyzed by means of SEM and electrochemical method. Formation dynamics about cerium conversion film on magnesium alloy in solution containing cerium salt and the anti-corrosion behavior of the conversion film in 3.5% NaCl solution were studied by electrochemical method respectively. The results shows that the conversion film is more compact at room temperature when concentration of cerium sulfate is 10 g·L-1 in the solution; the open circuit potential of the magnesium sample moves up to positive direction about 100 mV, the surface of conversion film becomes even and lustrous, and the adhesion intensity of conversion film increases when adding aluminum nitrate into the solution containing cerium salt. The pH value of the solution and immersion time of the sample in the solution also affect the surface morphology and anti-corrosion property of the conversion film. After covered by rare earths conversion film, the anti-corrosion property of magnesium alloy is obviously improved. Rare earth conversion film has self-repairing capability in corrosion medium.

  15. Preparation of UV curing crosslinked polyviologen film and its photochromic and electrochromic performances

    Science.gov (United States)

    Gao, Li-ping; Ding, Guo-jing; Wang, Yue-chuan; Yang, Yu-lin

    2011-11-01

    Polyether urethane diacrylate matrix (PEUDA) and acrylate-functional viologen (ACV2+) were successfully synthesized and characterized in detail by FTIR and 1H NMR spectra, respectively. Subsequently, they were used to prepare UV curing crosslinked polyviologen film in combination with 2-hydroxyethyl methacrylate (HEMA), trimethylolpropane ethoxylate triacrylate (TMPTA) and diphenyl (2, 4, 6-trimethylbenzoyl) phosphine oxide (TPO). UV curing approach confined the polyviologen film on ITO electrode, which imparted the film excellent adhesion ability to ITO glass, good solvent resistance, excellent chemical stability, excellent optical and electrochemical properties. The crosslinked PACV2+ film exhibited excellent photochromic and electrochromic performances. After UV illumination for 60 s, the crosslinked PACV2+ film can swiftly change its color from pale yellow to deep blue, while the optical transmission of crosslinked PACV2+ film at 610 nm did not change significantly and still retained about 63.6% after 30 cycles. Simultaneously, the cyclic voltammetry experiment showed the PACV2+ film can undergo repeatable electrochemical redox reactions with good reversibility beyond the 10th scan. Furthermore, the electrochromic device composed of the PACV2+ film and gel electrolyte film can undergo reversible color change in response to the external voltages of -2.0 V and 2.0 V, respectively, while the contrast of EC device at 610 nm did not change significantly and still retained about 39.5% after 10 cycles. This UV curing approach to preparing viologen-functional film offers a method to preparing large-scale photo- and electrochromic device, which is relatively simple, high productivity, energy saving, and environmental protection.

  16. Self-standing elastomeric composites based on lithium ferrites and their dielectric behavior

    Energy Technology Data Exchange (ETDEWEB)

    Soreto Teixeira, S.; Graça, M. P. F.; Costa, L. C. [I3N and Physics Department, University of Aveiro, 3810-193 Aveiro (Portugal); Dionisio, M. [REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Ilcíkova, M.; Mosnacek, J.; Spitalsky, Z. [Polymer Institute, Slovak Academy of Sciences, Dúbravská cesta 9, Bratislava (Slovakia); Krupa, I. [Polymer Institute, Slovak Academy of Sciences, Dúbravská cesta 9, Bratislava (Slovakia); Center for Advanced Materials, Qatar University, P.O. Box 2713, Doha (Qatar)

    2014-12-14

    Lithium ferrite (LiFe{sub 5}O{sub 8}) is an attractive material for technological applications due to its physical properties, which are significantly dependent on the preparation method and raw materials. In this work, LiFe{sub 5}O{sub 8} crystallites were obtained by controlled heat-treatment process at 1100 °C, of a homogeneous mixture of Li{sub 2}O-Fe{sub 2}O{sub 3} powders, prepared by wet ball-milling and using lithium and iron nitrates as raw materials. The main goal was the preparation of a flexible and self-standing tick composite film by embedding lithium ferrite particles in a polymeric matrix, taking advantage of the good mechanical properties of the polymer and of the electrical and dielectric properties of the ferrite. The selected polymer matrix was styrene-b-isoprene-b-styrene copolymer. To prepare the composites, the lithium ferrite particles were chemically modified in order to functionalize their surface. To analyse the influence of the particles surface modification, different composites were made, with modified and unmodified particles. The structure of the obtained composites was studied by FTIR, XRD, TGA, and DSC techniques. The dielectric properties were analysed, in the frequency range between 10 Hz and 1 MHz and in function of temperature in the range between −73 °C and 127 °C. These properties were related with the structure and concentration of the particles in the matrix network. The composites with the modified particles present higher dielectric constant, maintaining values of loss tangent sufficiently low (<10{sup −2}) that can be considered interesting for technological applications.

  17. Properties and characterization of bionanocomposite films prepared with various biopolymers and ZnO nanoparticles.

    Science.gov (United States)

    Kanmani, Paulraj; Rhim, Jong-Whan

    2014-06-15

    This study was aimed to develop biopolymer based antimicrobial films for active food packaging and to reduce environmental pollution caused by accumulation of synthetic packaging. The ZnO NPs were incorporated as antimicrobials into different biopolymers such as agar, carrageenan and CMC. Solvent casting method was performed to prepare active nanocomposite films. Methods such as FE-SEM, FT-IR and XRD were used to characterize resulting films. Physical, mechanical, thermal and antimicrobial properties were also examined. Remarkable surface morphological differences were observed between control and nanocomposite films. The crystallinity of ZnO was confirmed by XRD analysis. The addition of ZnO NPs increased color, UV barrier, moisture content, hydrophobicity, elongation and thermal stability of the films, while decreased WVP, tensile strength and elastic modulus. ZnO NPs impregnated films inhibited growth of L. monocytogenes and E. coli. So these newly prepared nanocomposite films can be used as active packaging film to extend shelf-life of food.

  18. Film properties of alumina passivation layer for silicon solar cells prepared by spin-coating method

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Ryosuke, E-mail: rwatanabe@st.seikei.ac.jp; Kawashima, Mizuho; Saito, Yoji

    2015-09-01

    We prepared alumina passivation films deposited by a sol-gel wet process for silicon substrates. Aluminum acetylacetonate was used as a precursor, and the solution was spin-coated onto silicon substrates. Calcination temperature dependence of the passivation quality of the films was evaluated mainly by measuring effective lifetime using a photo conductance decay technique and capacitance–voltage measurements. Also, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy were carried out to evaluate film properties. A large amount of negative fixed charge density (Q{sub f} = − 3.1 × 10{sup 12} cm{sup −2}) exists in the films calcined at 300 °C. On the other hand, a long effective lifetime of 400 μs was obtained for the sample calcined at 600 °C, and the passivation films had a large amount of positive fixed charge density (Q{sub f} = 3.6 × 10{sup 12} cm{sup −2}) with a low interface state density. - Highlights: • Alumina passivation films for silicon solar cells were prepared by spin-coating. • Electronic properties and the quality of passivation films were investigated. • Carrier lifetime was enhanced for the samples that were calcined above 400 °C. • The films calcined at 300 °C have high amount of negative fixed charge.

  19. New crosslinked cast films based on poly(vinyl alcohol: Preparation and physico-chemical properties

    Directory of Open Access Journals (Sweden)

    C. Birck

    2014-12-01

    Full Text Available In this paper, we propose a green route to prepare insoluble poly(vinyl alcohol (PVOH cast films with potential application as antimicrobial packaging. First PVOH films were cast from different aqueous solutions and analyzed by Differential Scanning Calorimetry (DSC and Dynamic Mechanical Analysis (DMA to determine their physical properties under two storage conditions. In order to obtain insoluble films, PVOH was then crosslinked by citric acid (CTR as confirmed by Nuclear Magnetic Resonance (NMR analyses. The crosslinking reaction parameters (curing time, crosslinker content were studied by comparing the characteristics of PVOH/CTR films, such as free COOH content and glass transition temperature (Tg value, as well as the impact of the crosslinking reaction on mechanical properties. It was found that for 40 and 10 wt% CTR contents, 120 and 40 min of crosslinking times were necessary to bind all CTR respectively. Brittle films were obtained for 40 wt% CTR whereas 10 wt% CTR content led to ductile films. Finally, films containing hydroxypropyl-β-cyclodextrin (HPβCD, chosen as a potential vector of antimicrobial agent, were prepared. The obtained results show that the incorporation of HPβCD in the PVOH matrix does not mainly influence the physical and mechanical properties of the films.

  20. Preparation and Characterization of Silver Liquid Thin Films for Magnetic Fluid Deformable Mirror

    Directory of Open Access Journals (Sweden)

    Lianchao Zhang

    2015-01-01

    Full Text Available Silver liquid thin film, formed by silver nanoparticles stacking and spreading on the surface of the liquid, is one of the important parts of magnetic fluid deformable mirror. First, silver nanoparticles were prepared by liquid phase chemical reduction method using sodium citrate as reducing agent and stabilizer and silver nitrate as precursor. Characterization of silver nanoparticles was studied using X-ray diffractometer, UV-vis spectrophotometer, and transmission electron microscope (TEM. The results showed that silver nanoparticles are spherical and have a good monodispersity. Additionally, the effect of the reaction conditions on the particle size of silver is obvious. And then silver liquid thin films were prepared by oil-water two-phase interface technology using as-synthesized silver nanoparticles. Properties of the film were investigated using different technology. The results showed that the film has good reflectivity and the particle size has a great influence on the reflectivity of the films. SEM photos showed that the liquid film is composed of multilayer silver nanoparticles. In addition, stability of the film was studied. The results showed that after being stored for 8 days under natural conditions, the gloss and reflectivity of the film start to decrease.

  1. Preparation and Grafting Functionalization of Self-Assembled Chitin Nanofiber Film

    Directory of Open Access Journals (Sweden)

    Jun-ichi Kadokawa

    2016-07-01

    Full Text Available Chitin is a representative biomass resource comparable to cellulose. Although considerable efforts have been devoted to extend novel applications to chitin, lack of solubility in water and common organic solvents causes difficulties in improving its processability and functionality. Ionic liquids have paid much attention as solvents for polysaccharides. However, little has been reported regarding the dissolution of chitin with ionic liquids. The author found that an ionic liquid, 1-allyl-3-methylimidazolium bromide (AMIMBr, dissolved chitin in concentrations up to ~4.8 wt % and the higher contents of chitin with AMIMBr gave ion gels. When the ion gel was soaked in methanol for the regeneration of chitin, followed by sonication, a chitin nanofiber dispersion was obtained. Filtration of the dispersion was subsequently carried out to give a chitin nanofiber film. A chitin nanofiber/poly(vinyl alcohol composite film was also obtained by co-regeneration approach. Chitin nanofiber-graft-synthetic polymer composite films were successfully prepared by surface-initiated graft polymerization technique. For example, the preparation of chitin nanofiber-graft-biodegradable polyester composite film was achieved by surface-initiated graft polymerization from the chitin nanofiber film. The similar procedure also gave chitin nanofiber-graft-polypeptide composite film. The surface-initiated graft atom transfer radical polymerization was conducted from a chitin macroinitiator film derived from the chitin nanofiber film.

  2. Oromucosal film preparations: points to consider for patient centricity and manufacturing processes.

    Science.gov (United States)

    Krampe, Raphael; Visser, J Carolina; Frijlink, Henderik W; Breitkreutz, Jörg; Woerdenbag, Herman J; Preis, Maren

    2016-01-01

    According to the European Pharmacopoeia, oromucosal films comprise mucoadhesive buccal films and orodispersible films. Both oral dosage forms receive considerable interest in the recent years as commercially available pharmaceutical products and as small scale personalized extemporaneous preparations. In this review, technological issues such as viscosity of the casting liquid, mechanical properties of the film, upscaling and the stability of the casting solution and produced films will be discussed. Furthermore, patient-related problems like appearance, mucosal irritation, taste, drug load, safety and biopharmaceutics are described. Current knowledge and directions for solutions are summarized. The viscosity of the casting solution is a key factor for producing suitable films. This parameter is amongst others dependent on the polymer and active pharmaceutical ingredient, and the further excipients that are used. For optimal patient compliance, an acceptable taste and palatability are desirable. Safe and inert excipients should be used and appropriate packaging should be provided to produced films. Absorption through the oral mucosa will vary for each active compound, formulation and patient, which gives rise to pharmacokinetic questions. Finally, the European Pharmacopoeia needs to specify methods, requirement and definitions for oromucosal film preparations based on bio-relevant data.

  3. Preparing hydrophobic nanocellulose-silica film by a facile one-pot method.

    Science.gov (United States)

    Le, Duy; Kongparakul, Suwadee; Samart, Chanatip; Phanthong, Patchiya; Karnjanakom, Surachai; Abudula, Abuliti; Guan, Guoqing

    2016-11-20

    Hydrophobic nanocellulose-silica film was successfully prepared by a facile one-pot method using tetraethoxysilane (TEOS) and dodecyl triethoxylsilane (DTES). Morphological characterization of the hydrophobic nanocellulose-silica (NC-SiO2-DTES) film showed well self-assembled DTES modified silica spherical nanoparticles with the particle sizes in the range of 88-126nm over the nanocellulose film. The hydrophobicity of the NC-SiO2-DTES film was achieved owing to the improvement of roughness of the nanocellulose film by coating dodecyl- terminated silica nanoparticles. An increase in DTES loading amount and reaction time increased the hydrophobicity of the film, and the optimum condition for NC-SiO2-DTES film preparation was achieved at DTES/TEOS molar ratio of 2.0 for 8h reaction time. Besides, the NC-SiO2-DTES film performed superoleophilic property with octane and hexadecane contact angles of 0°. It also showed an excellent hydrophobic property over all pH values ranged from 1 to 14.

  4. Preparation, and Structural and Magnetic Properties of Ca Substituted Magnesium Ferrite with Composition MgCaxFe2−xO4 (x = 0.00, 0.01, 0.03, 0.05, 0.07

    Directory of Open Access Journals (Sweden)

    K. K. Bamzai

    2014-01-01

    Full Text Available Calcium substituted magnesium ferrite with composition MgCaxFe2−xO4 (where x = 0.00, 0.01, 0.03, 0.05, 0.07 was prepared by ceramic technique. These compositions were then subjected to detailed study for structural and magnetic properties. X-ray diffraction studies reveal the formation of single phase cubic spinel. The values of lattice constant increase with the increase in calcium concentration from x = 0.00 to x = 0.03 and then decrease. Scanning electron microscopic (SEM technique was used to study the morphology of the grown materials. The grain size was calculated using average intercept line method. The elemental composition of pure and calcium substituted magnesium ferrite was obtained from energy dispersive X-ray analysis (EDAX spectrum. The hysteresis loop confirms the magnetic behaviour of the prepared composition, which is then discussed on the basis of cation distribution. The parameters such as saturation magnetization, coericivity, and retentivity are calculated. The Curie temperature was found to decrease with increasing calcium content.

  5. Optimization of AZO films prepared on flexible substrates

    Indian Academy of Sciences (India)

    C C Hu; T W Lu; C Y Chou; J T Wang; H H Huang; C Y Hsu

    2014-10-01

    Transparent conductive Al2O3-doped zinc oxide (in AZO, Al2O3 content is ∼ 2 wt%) thin films are deposited on flexible polyethylene terephthalate (PET) substrates, using radio frequency (rf) magnetron sputtering. The Taguchi method with an 9 (34) orthogonal array, a signal-to-noise ratio and analysis of variance (ANOVA) was used to determine the performance characteristics of the coating operations. Using grey relational analysis, the optimization of these deposition process parameters for AZO thin films with multiple characteristics was performed. The electrical resistivity of AZO/PET films is reduced from 2.6 × 10-2 to 5.5 × 10-3 -cm and the visible range transmittance is > 83%, using the grey relational analysis. ANOVA results for the grey relational grade indicate that rf power and working pressure are the two most influential factors. The effect of the rf power (in the range from 30 to 70 W) and the argon working pressure (in the range from 0.90 to 1.1 Pa) on the morphology and optoelectronic performance of AZO films are also investigated. An analysis of the influence of the dominant parameters in the optimal design region is helpful for adjustment of the coating parameters.

  6. Surface textured molybdenum doped zinc oxide thin films prepared for thin film solar cells using pulsed direct current magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Y.C., E-mail: ielinyc@cc.ncue.edu.tw; Wang, B.L.; Yen, W.T.; Shen, C.H.

    2011-06-01

    In this study, we examined the effect of etching on the electrical properties, transmittance, and scattering of visible light in molybdenum doped zinc oxide, ZnO:Mo (MZO) thin films prepared by pulsed direct current magnetron sputtering. We used two different etching solutions - KOH and HCl - to alter the surface texture of the MZO thin film so that it could trap light. The experimental results showed that an MZO film with a minimum resistivity of about 8.9 x 10{sup -4} {Omega} cm and visible light transitivity of greater than 80% can be obtained without heating at a Mo content of 1.77 wt.%, sputtering power of 100 W, working pressure of 0.4 Pa, pulsed frequency of 10 kHz, and film thickness of 500 nm. To consider the effect of resistivity and optical diffuse transmittance, we performed etching of an 800 nm thick MZO thin film with 0.5 wt.% HCl for 3-6 s at 300 K. Consequently, we obtained a resistivity of 1.74-2.75 x 10{sup -3} {Omega} cm, total transmittance at visible light of 67%-73%, diffuse transmittance at visible light of 25.1%-28.4%, haze value of 0.34-0.42, and thin film surface crater diameters of 220-350 nm.

  7. Preparation of stable aqueous solution of keratins, and physiochemical and biodegradational properties of films.

    Science.gov (United States)

    Yamauchi, K; Yamauchi, A; Kusunoki, T; Kohda, A; Konishi, Y

    1996-08-01

    A stable aqueous solution of reduced keratins was prepared by extracting the proteins from wool (Corriedale) with a mixture of urea, mercaptanol, surfactant, and water at 40-60 degrees C. Sodium dodecyl sulfate was especially effective as a surfactant, not only in promoting extraction but also in stabilizing the aqueous protein solution. The proteins had the following constants: MW, 52,000-69,000 daltons; cysteine content, 8-9 mol%; pl about 6.7. A clear film was readily prepared from a keratin solution containing glycerol. The film was insoluble in water and organic solvents including dimethyl sulfoxide. The keratin film was permeable to glucose, urea, and sodium chloride. The keratin film was degraded in vitro (by trypsin) and in vivo (by subcutaneous embedding in mice).

  8. Studies on Preparation of Co-Bi Alloy Films by Electrodeposition From Nonaqueous Medium

    Institute of Scientific and Technical Information of China (English)

    LI Gao-ren; TONG Ye-xiang; LIU Guan-kun

    2003-01-01

    Cyclic voltammetry and potentiostatic electrolysis were used to investigate the preparation of Co-Bi alloy films in a LiClO4-DMSO system. The experimental results indicate that the Co-Bi alloy films containing 14.35%-29.77% Co can be prepared via potentionstatic electrolysis on Cu substrates, at deposition potential -1.10--1.65 V(vs. SCE) and by controlling the system composition and deposition condition. They are uniform gray films with a metallic luster and they are adhered firmly to the Cu substrate. The films were analyzed by EDS, SEM and XRD. After heat treatment of crystallization at 275 ℃ for 1 h, the alloy phase of Co-Bi can be confirmed via the XRD pattern.

  9. Continuous Preparation of Carbon Nanotube Film and Its Applications in Fuel and Solar Cells.

    Science.gov (United States)

    Luo, Xiao Gang; Huang, Xin Xin; Wang, Xiao Xia; Zhong, Xin Hua; Meng, Xin Xin; Wang, Jian Nong

    2016-03-01

    So far, simultaneously realizing the continuous, controllable, and scalable preparation of carbon nanotube (CNT) film has remained a big challenge. Here, we report a scalable approach to continuously prepare CNT film with good control of film size and thickness. This is achieved through the layer-by-layer condensation and deposition of a cylindrical CNT assembly that is continuously produced from a floating catalyst CVD reactor on a paper strip. The promising applications of such a film are demonstrated by directly using it as an effective protecting layer for the Pt/C catalyst in proton exchange membrane fuel cells and as an efficient counter electrode material in quantum-dot-sensitized solar cells.

  10. Preparation of porous titanium oxide films onto indium tin oxide for application in organic photovoltaic devices

    Energy Technology Data Exchange (ETDEWEB)

    Macedo, Andreia G. [Laboratorio de Dispositivos Nanoestruturados, Departamento de Fisica, Universidade Federal do Parana, Curitiba, Parana (Brazil); Mattos, Luana L.; Spada, Edna R.; Serpa, Rafael B.; Campos, Cristiani S. [Laboratorio de Sistemas Nanoestruturados, Departamento de Fisica, Universidade Federal de Santa Catarina, Florianopolis, Santa Catarina (Brazil); Grova, Isabel R.; Ackcelrud, Leni [Laboratorio de Polimeros Paulo Scarpa, Departamento de Quimica, Universidade Federal do Parana, Curitiba, Parana (Brazil); Reis, Francoise T.; Sartorelli, Maria L. [Laboratorio de Sistemas Nanoestruturados, Departamento de Fisica, Universidade Federal de Santa Catarina, Florianopolis, Santa Catarina (Brazil); Roman, Lucimara S., E-mail: lsroman@fisica.ufpr.br [Laboratorio de Dispositivos Nanoestruturados, Departamento de Fisica, Universidade Federal do Parana, Curitiba, Parana (Brazil)

    2012-05-01

    In this work, porous ordered TiO{sub 2} films were prepared through sol gel route by using a monolayer of polystyrene spheres as template on indium-tin oxide/glass substrate. These films were characterized by SEM, AFM, Raman spectroscopy, UV-vis absorbance and XRD. The UV-vis absorbance spectrum show a pseudo band gap (PBG) with maxima at 460 nm arising from the light scattering and partial or total suppression of the photon density of states, this PBG can be controlled by the size of the pore. We also propose the use of this porous film as electron acceptor electrode in organic photovoltaic cells; we show that devices prepared with porous titania displayed higher efficiencies than devices using compact titania films as electrode. Such behaviour was observed in both bilayer and bulk heterojunction devices.

  11. Preparation of transparent conductive ZnO:Tb films and their photoluminescence properties

    Institute of Scientific and Technical Information of China (English)

    Fang Ze-Bo; Tan Yong-Sheng; Liu Xue-Qin; Yang Ying-Hu; Wang Yin-Yue

    2004-01-01

    Tb-doped Zinc oxide (ZnO:Tb) films were prepared by RF reactive magnetron sputtering of a Zn target withsome Tb-chips attached. The results show that the appropriate Tb ions incorporated into ZnO films can improve the structural and electrical properties of ZnO films. Photoluminescence (PL) measurements show that the characteristic emission lines correspond to the intra-4fn-shell transitions in Tbs+ ions at room temperature. Under the optimal conditions, the ZnO:Tb films were prepared with the lowest resistivity (ρ) of 9.34 × 10-4Ωcm, transmittance over 80% at the visible region and the strong blue emission.

  12. Electrochemical preparation of Er-Co-Bi thin film in organic bath by cyclic electrodeposition method

    Institute of Scientific and Technical Information of China (English)

    李高仁; 童叶翔; 刘冠昆

    2004-01-01

    Cyclic electrodeposition was used to investigate the preparation of Er-Co-Bi alloy thin film in DMSO system. Experimental results indicate that Er-Co-Bi alloy thin film containing 14.83 %- 32.65 % Er is prepared from 0. 1 mol/L ErCl3 +0. 1 mol/L CoCl2 + 0.1 mol/L Bi(NO3 )3 + 0.1 mol/L LiCl+DMSO system by cyclic electrodeposition on Cu substrate. The optimum cyclic potential of electrodeposition is that upper potential is within a potential range from -0.50 V to -1.00 V and lower potential is within a potential range from -2.00 V to -2.60 V.The surface of alloy thin film observed by scanning electron microscope is black, adhesive and has metallic luster.The film is amorphous proved by the X-ray diffractometry.

  13. Characteristics of zinc oxide nanorod array/titanium oxide film heterojunction prepared by aqueous solution deposition

    Science.gov (United States)

    Lee, Ming-Kwei; Hong, Min-Hsuan; Li, Bo-Wei

    2016-07-01

    The characteristics of a ZnO nanorod array/TiO2 film heterojunction were investigated. A TiO2 film was prepared on glass by aqueous solution deposition with precursors of ammonium hexafluorotitanate and boric acid at 40 °C. Then, a ZnO seed layer was prepared on a TiO2 film/glass substrate by RF sputtering. A vertically oriented ZnO nanorod array was grown on a ZnO seed layer/TiO2 film/glass substrate by aqueous solution deposition with precursors of zinc nitrate and hexamethylenetetramine (HMT) at 70 °C. After thermal annealing in N2O ambient at 300 °C, this heterojunction used as an oxygen gas sensor shows much better rise time, decay time, and on/off current ratio than as-grown and annealed ZnO nanorods.

  14. Preparation of polysilsesquioxane-urethaneacrylate copolymer film reinforced with chitin nanofibers.

    Science.gov (United States)

    Ifuku, Shinsuke; Ikuta, Akiko; Hosomi, Tetsuya; Kanaya, Shingo; Shervani, Zameer; Morimoto, Minoru; Saimoto, Hiroyuki

    2012-07-01

    Chitin nanofibers (CNFs) reinforced silsesquioxane-urethaneacrylate (SSQ-UA) copolymer films were prepared. CNFs-SSQ-UA nanocomposite films were highly transparent due to the filling of nanometer sized (10-20 nm) CNFs inside the hybrid organic-inorganic SSQ-UA copolymer. CNFs due to their crystalline structure drastically increased Young's moduli and the tensile strengths of the composite and decreased the thermal expansion. High thermal stability of polysilsesquioxane improved heat resistance of CNFs.

  15. Preparation and Characterization of Polyvinylidene Fluoride/Graphene Superhydrophobic Fibrous Films

    OpenAIRE

    Rasoul Moradi; Javad Karimi-Sabet; Mojtaba Shariaty-Niassar; Mohammad A. Koochaki

    2015-01-01

    A new strategy to induce superhydrophobicity via introducing hierarchical structure into the polyvinylidene fluoride (PVDF) film was explored in this study. For this purpose nanofibrous composite films were prepared by electrospinning of PVDF and PVDF/graphene blend solution as the main precursors to produce a net-like structure. Various spectroscopy and microscopy methods in combination with crystallographic and wettability tests were used to evaluate the characteristics of the synthesized f...

  16. Preparation and Properties of Functional Graphene/Thermoplastic Polyurethane Composite Film

    OpenAIRE

    ZHENG Hui-dong; OU Zhong-xing; ZHENG Yu-ying; XIAO Dong-sheng; CAO Ning-ning

    2016-01-01

    The modified graphene oxide(DD-GO) was reacted by the Didodecyldimethylammonium bromide (DDAB) and graphene oxide,and then reduced via L-ascorbic acid to obtain functional graphene(DD-RGO). Functional graphene (DD-RGO)/thermoplastic polyurethane (TPU) composite films were prepared by solution on the coating machine. The morphology and properties of DD-RGO/TPU composite films were investigated by FTIR, XRD, FE-SEM, oxygen transmission rate tester and high resistance meter. The results show tha...

  17. Iron Oxide Films Prepared by Rapid Thermal Processing for Solar Energy Conversion

    DEFF Research Database (Denmark)

    Wickman, B.; da Silva Fanta, Alice Bastos; Burrows, Andrew

    2017-01-01

    considerably. Herein, we present hematite thin films fabricated via one-step oxidation of Fe by rapid thermal processing (RTP). In particular, we investigate the effect of oxidation temperature on the PEC properties of hematite. Films prepared at 750 °C show the highest activity towards water oxidation......, potentially also on nanostructured electrodes, where retaining high surface area is crucial to maximize performance....

  18. Facile preparation of smooth perovskite films for efficient meso/planar hybrid structured perovskite solar cells.

    Science.gov (United States)

    Zhang, Meng; Yu, Hua; Yun, Jung-Ho; Lyu, Miaoqiang; Wang, Qiong; Wang, Lianzhou

    2015-06-21

    Smooth organolead halide perovskite films for meso/planar hybrid structured perovskite solar cells were prepared by a simple compressed air blow-drying method under ambient conditions. The resultant perovskite films show high surface coverage, leading to a device power conversion efficiency of over 10% with an open circuit voltage up to 1.003 V merely using pristine poly(3-hexylthiophene) (P3HT) as a hole transporter.

  19. Amorphous Indium Selenide Thin Films Prepared by RF Sputtering: Thickness-Induced Characteristics.

    Science.gov (United States)

    Han, Myoung Yoo; Park, Yong Seob; Kim, Nam-Hoon

    2016-05-01

    The influence of indium composition, controlled by changing the film thickness, on the optical and electrical properties of amorphous indium selenide thin films was studied for the application of these materials as Cd-free buffer layers in CI(G)S solar cells. Indium selenide thin films were prepared using RF magnetron sputtering method. The indium composition of the amorphous indium selenide thin films was varied from 94.56 to 49.72 at% by increasing the film thickness from 30 to 70 nm. With a decrease in film thickness, the optical transmittance increased from 87.63% to 96.03% and Eg decreased from 3.048 to 2.875 eV. Carrier concentration and resistivity showed excellent values of ≥1015 cm(-3) and ≤ 10(4) Ω x cm, respectively. The conductivity type of the amorphous indium selenide thin films could be controlled by changing the film-thickness-induced amount of In. These results indicate the possibility of tuning the properties of amorphous indium selenide thin films by changing their composition for use as an alternate buffer layer material in CI(G)S solar cells.

  20. [Preparation and spectral characterization of CdS(y)Te(1-y) thin films].

    Science.gov (United States)

    Li, Wei; Feng, Liang-Huan; Wu, Li-Li; Zhang, Jing-Quan; Li, Bing; Lei, Zhi; Cai, Ya-Ping; Zheng, Jia-Gui; Cai, Wei; Zhang, Dong-Min

    2008-03-01

    CdS(y)Te(1-y) (0 thin films were prepared on glass substrates by co-evaporation of powders of CdTe and CdS. For the characterization of the structure and composition of the CdS(y)Te(1-y) thin films the X-ray diffraction (XRD) and energy-dispersive spectroscopy (EDS) were used. The results indicate that the values of sulfur content y detected and controlled by the quartz wafer detector show good agreement with the EDS results. The films were found to be cubic for x or = 0.3. The 20-50 nm of grain sizes for CdS(y)Te(1-y) thin films were calculated using a method of XRD analysis. Finally, the optical properties of CdS(y)Te(1-y) thin films were characterized by UV-Vis-NIR spectroscopy alone. According to a method from Swanepoel, together with the first-order Sellmeier model, the thickness, of d-535 nm, energy gap of E(g)-1.41 eV, absorption coefficient, alpha(lambda) and refractive index, n(lambda) of CdS(0.22) Te(0.78) thin films were determined from the transmittance at normal incidence of light in the wavelength range 300-2 500 nm. The results also indicate that the CdS(y)Te(1-y) thin films with any composition (0 thin films can be implemented for other semiconductor thin films.

  1. Preparation and Characterization of Hydroxypropyl Methylcellulose/Polycarbophil Mucoadhesive Blend Films Using a Mixture Design Approach.

    Science.gov (United States)

    Kraisit, Pakorn; Limmatvapirat, Sontaya; Nunthanid, Jurairat; Sriamornsak, Pornsak; Luangtana-Anan, Manee

    2017-03-01

    The objectives of this study were to prepare the hydroxypropyl methylcellulose (HPMC)/polycarbophil (PC) mucoadhesive blend film and to investigate the main and interaction effect of HPMC and PC mixtures on the physicochemical and mechanical properties of blend films using a simplex lattice mixture design approach. The cubic and quadratic models were selected to analyze mucoadhesive properties in terms of work of adhesion and maximum detachment force, respectively. It was shown that HPMC/PC blend film had higher mucoadhesive properties than pure HPMC film. The suitable models for analyzing swelling index of blend films at various times were assessed. The puncture strength, % elongation and hydrophilicity of films were also examined. The pure HPMC film displayed more homogeneous and smoother structures compared with the blend film, as observed by scanning electron microscope and atomic force microscopy. Intermolecular hydrogen bonding between HPMC and PC was detected using Fourier transform infrared and X-ray diffraction. Therefore, the blend film shows high potential for use as a buccal delivery system.

  2. Preparation and Properties of Doped Lanthanum Gallate Film on a Ni/SDC Porous Anode Support

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A 65.8-μm dense doped lanthanum gallate La0.8Sr0.2Ga0.85Mg0.15O2.825 (LSGM)film was prepared on a porous Ni/SDC(samarium doped ceria, Ce0.8Sm0.2O1.9) anode support by colloid suspension deposition with incomplete crystallization LSGM powder as a starting material. The phase composition and micromorphology of the LSGM film were characterized by X-ray diffraction and scanning electron microscopy. The electrical properties of the LSGM film and the performances of the LSGM film solid oxide fuel cell were also analyzed. The results show that both the dense LSGM film on the porous anode support, and the required phase composition of the LSGM film were obtained simultaneously by sintering at 1400℃ for 6 h. The adhesion between the LSGM film and the porous anode support is very strong. The electrical conductivities of the LSGM film on the porous anode support are 0. 113 and 0. 173 S/cm at 800and 850 ℃, respectively. The maximum output power density of the LSGM film cell is 177 mW/cm2 at 700 ℃.

  3. Structure, Morphology and Chemical Synthesis of Mg1-xZnxFe2O4 Nano-Ferrites Prepared by Citrate-Gel Auto Combustion Method

    Directory of Open Access Journals (Sweden)

    D.Ravikumar

    2014-04-01

    Full Text Available Mg-Zn Nano ferrites having chemical formula Mg1-xZnxFe2O4(where x=0.0, 0.2, 0.4, 0.6, 0.8, 1.0 were synthesized by the citrate-gel auto combustion method. Synthesized powders were sintered at 500oC for four hours in air and characterized by XRD, SEM and EDS.XRD analysis shows that cubic spinal structure of the ferrites and the crystalline sizes (D were found in the range 25-35 nm. The values of the lattice parameter (a increases and X-ray density (dx increases with doping of Zn content. Scanning Electron Microscopy (SEM studies revealed Nano nature of the samples. An elemental composition of the samples was studied by using Energy Dispersive Spectroscopy (EDS. The observed results can be explained on the basis of composition and crystallite size.

  4. Simple way for preparation of ZnO films by surfactant mediated spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Stambolova, Irina; Blaskov, Vladimir; Shipochka, Maria [Institute of General and Inorganic Chemistry, BAS, Acad. G. Bonchev St., bl.11, 1113 Sofia (Bulgaria); Vassilev, Sasho [Institute of Electrochemistry and Energy Systems, BAS, Acad. G. Bonchev St., bl.10, 1113 Sofia (Bulgaria); Petkova, Vilma [Institute of Mineralogy and Crystallography ' Acad. Ivan Kostov' , BAS, Acad. G. Bonchev St., bl.107, 1113 Sofia (Bulgaria); Loukanov, Alexandre, E-mail: alexandre_loukanov@abv.bg [Laboratory of Engineering NanoBiotechnology, Department of Engineering Geoecology, University of Mining and Geology ' St. Ivan Rilski' , Sofia 1700 (Bulgaria)

    2012-08-01

    Highlights: Black-Right-Pointing-Pointer ZnO was prepared by surfactant mediated spray pyrolysis. Black-Right-Pointing-Pointer The film surface morphology can be enhanced by PVA addition. Black-Right-Pointing-Pointer The PVA improves significant the photocatalytic activity of ZnO. Black-Right-Pointing-Pointer The zinc acetate precursor is preferred for film preparation than nitrate one. - Abstract: Nanocrystalline porous ZnO films are deposited onto alumina foil substrates by polyvinyl alcohol (PVA) modified spray pyrolysis. Water and ethanol-water mixture were used for preparation of the sols. The effect of polyvinyl alcohol on the morphological and photocatalytical properties of ZnO films was studied. It was found that the polyvinyl alcohol plays important role in formation of porous films structure with ganglia like morphology. Relatively compact granular morphology was observed for the ZnO samples, grown without organic surfactant. The X-ray diffraction patterns revealed the formation of phase-pure ZnO thin films. The FTIR spectra and DTA-TG analyses of the precursor mixtures: Zn(CH{sub 3}COOH){sub 2}{center_dot}2H{sub 2}O and Zn(NO{sub 3}){sub 2}{center_dot}6H{sub 2}0 with PVA revealed that ZnO is formed before the final decomposition of the polymer at 350 Degree-Sign C. It was observed that both: the acetate precursor and the organic surfactant could enhance significantly the photocatalytic properties of the ZnO films. The films obtained from sols, containing PVA showed better photocatalytic decolorization of Malachite Green dye, than the films, deposited from unmodified sols.

  5. The influence of precursor films on CIGS films prepared by ion beam sputtering deposition

    Science.gov (United States)

    Zhao, Jun; Fan, Ping; Liang, Guangxing; Zheng, Zhuanghao; Zhang, Dongping; Chen, Chaoming

    2013-12-01

    The CuInGa(CIG) precursor films were grown by ion beam sputtering continuously CuGa/CuIn and CuIn/CuGa, and then selenized CIG to fabricate CIGS absorber films on molybdenum substrates . They were annealed in the same vacuum chamber and under the same temperature (500°C). The CIGS thin films were characterized with X-ray diffraction (XRD), Energy dispersive spectroscopy (EDS) and scanning electron microscopy (SEM) in order to study the microstructures, composition, surface morphology, electrical properties, respectively. The results showed that the CIGS thin films appeared smooth and compact with a sequence of Mo/CuGa/CuIn/Se, which were mainly of chalcopyrite structure. The CIGS thin films got the strongest diffraction peak intensity and were with good crystalline quality.

  6. Electrochromic NiO thin films prepared by spin coating

    Science.gov (United States)

    Özütok, F.; Demiri, S.; Özbek, E.

    2017-02-01

    Recently, smart windows are very important because they are often being used in smart buildings and car glasses (windows). At this point, producing effective electrochromic materials is so necessary. In this study, we produced NiO thin films by using spin coating technique on In-doped SnO2 (ITO) substrate. Nickel proportions of these nickel oxide (NiO) films are 3, 5 and 7 %. Nickel acetate tetrahydrate is the initial solution and solvents are ethylene gl ycol and n-hexzane. Structural properties and surface images are investigated by using x-ray diffactometer (XRD) and scanning electron microscope (SEM) device, respectively. In addition, electrochemical behavior is investigated by cyclic voltammetry. A correlation between surface morphology and electrochromic performance was observed as well.

  7. Preparation and characterization of tungsten diselenide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Pouzet, J.; Bernede, J.C. (Lab. de Physique des Materiaux pour l' Electronique, Faculte des Sciences et des Techniques, 44 - Nantes (France)); Khellil, A. (Lab. de Micro-Optoelectronique, Univ. d' Oran-Es-Senia (Algeria)); Essaidi, H.; Benhida, S. (Lab. de Physique des Materiaux pour l' Electronique, Faculte des Sciences et des Techniques, 44 - Nantes (France))

    1992-02-28

    WSe{sub 2} layers synthesized by annealing tungsten foils and r.f.-sputtered tungsten thin films under selenium pressure have been investigated by scanning electron microscopy, X-ray analysis, X-ray photoelectron spectroscopy (XPS), optical absorption and electrical resistance measurements. It has been found that stoichiometric layers are obtained after appropriate processing at a temperature lower than the glass melting temperature. The films crystallize in the hexagonal structure. The crystallites develop preferentially along the c axis. The binding energies deduced from the XPS lines were found to be in good agreement with those of the reference powder. The electrical resistance is governed by hopping conduction in the low temperature range (80-250 K) and by grain-boundary-scattering mechanisms at higher temperature. (orig.).

  8. Preparation and characterization of crystalline titania film on polyimide substrate by SILAR

    Science.gov (United States)

    Shi, Yaping; Wu, Yiyong; Sun, Chengyue; Huo, Mingxue

    2014-10-01

    Crystalline titania films were prepared on the flexible polyimide (Kapton) substrates using the successive ionic layer adsorption and reaction (SILAR) technique modified with mixed organic amine template agents at room temperature. The titania film with the organic amine template agents presents orderly stacked morphology with cross linked V-shaped strips, and it composes of mainly anatase and minor rutile phases with N doping. Structural and morphology analysis indicates that there includes two parallel deposition growth processes: One is adsorption of the template agents and reaction with Ti4+ ions on the constraint region; and the other is a normal SILAR process of including the adsorption of Ti4+ ions and reaction with hydroxyl groups. The organic amine templates and their specific adsorption induce and direct the crystallization of the titania films. Crystal structure of the titania film was confirmed by its excellent photo catalytic property of the films, detected by the degradation test of MB.

  9. Preparation and study of thickness dependent electrical characteristics of zinc sulfide thin films

    Indian Academy of Sciences (India)

    A U Ubale; D K Kulkarni

    2005-02-01

    Zinc sulfide thin films have been deposited onto glass substrates by chemical bath deposition. The various deposition parameters such as volume of sulfide ion source, pH of bath, deposition time, temperature etc are optimized. Thin films of ZnS with different thicknesses of 76–332 nm were prepared by changing the deposition time from 6–20 h at 30°C temperature. The effect of film thickness on structural and electrical properties was studied. The electrical resistivity was decreased from 1.83 × 105 -cm to 0.363 × 105 -cm as film thickness decreased from 332 nm to 76 nm. The structural and activation energy studies support this decrease in the resistivity due to improvement in crystallinity of the films which would increase the charge carrier mobility and decrease in defect levels with increase in the thickness.

  10. Electrical properties of chemically prepared nonstoichiometric CuIn(S,Se)2 thin films

    Indian Academy of Sciences (India)

    R H Bari; L A Patil; A Soni; G S Okram

    2007-04-01

    Polycrystalline thin films of copper indium sulphoselenide [CuIn(S,Se)2] were deposited on glass substrate by chemical bath deposition technique. The deposition parameters such as pH, temperature and time were optimized. A set of films having different elemental compositions was prepared by varying Cu/In ratio from 1.87–12.15. The films were characterized by X-ray diffraction (XRD) and energy dispersive X-ray analysis (EDAX). The chemical composition of the CuIn(S,Se)2 was found to be nonstoichiometric. The d.c. conductivities of the films were studied below and near room temperature. The thermo-electric power of the films was also measured and type of semiconductivity was ascertained.

  11. Preparation and Photochromic Properties of Hybrid Thin Films Based on Heteropolyoxometallate and Polyacrylamide

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    series of photochromic hybrid films were prepared through entrapping Dawson type tungsten heteropolyoxometallates (P2W18O626-) and molybdenum heteropolyoxometallate (P2Mo18O626-) into polyacrylamide matrix. FTIR results showed that the Dawson geometry of heteropolyoxometallates is still preserved inside the composites and strong coulombic interaction is built between heteropolyoxometallates and polyacrylamide via hydrogen bonding. Irradiated with ultraviolet light, the transparent films change from colorless to blue and show reversible photochromism.The bleaching process occurs when the films are in contact with air or O2 in the dark. The molybdenum heteropolyoxometallate hybrid film has higher photochromic efficiency and slower bleaching reaction than tungsten heteropolyoxometallate hybrid film. ESR results indicated that polyacrylamide is a hydrogen donor and the photoreduced process is in accordance with the radical mechanism.

  12. Preparation, Growth Mechanisms and Characterizations of ZnSe Films via the Solvothermal Method

    Institute of Scientific and Technical Information of China (English)

    LI Huan-yong; JIE Wan-qi; ZHAO Hai-tao

    2006-01-01

    With diethylamine as a solvent, ZnSe films were formed on the Si substrate directly from zinc and selenium through the modified solvothermal method. The effects of holding temperature, deposition time and substrate surface treatment on the quality and morphologies of the ZnSe films were investigated. The growth mechanism of ZnSe films was proved to be a layer-nucleation growth process, which was tied in with the Stranski-Krastanov (SK) model. ZnSe films were identified by the X-ray diffraction pattern (XRD), the scanning electron microscope (SEM), the X-ray photoelectron spectroscope (XPS) and the photoluminescence (PL) techniques. The results indicate that the modified solvothermal method with diethylamine as a solvent is suitable to prepare high quality ZnSe films.

  13. Preparation and Structural Characterization of Superionic Conductor RbAg4I5 Crystalline Grain Film

    Science.gov (United States)

    Cao, Yang; Sun, Hong-San; Sun, Jia-Lin; Tian, Guang-Yan; Xing, Zhi; Guo, Ji-Hua

    2003-05-01

    Superionic conductor RbAg4I5 crystalline grain films were prepared by vacuum thermal evaporation on NaCl crystalline substrates. The surface morphology, microstructure and the electronic energy states of the films were examined by atomic force microscopy, transmission-electron microscopy, x-ray diffraction and x-ray photoelectron spectroscopy. The results show that the obtained RbAg4I5 layer has an epitaxial film of perfect crystalline structure, and the unit cell of crystalline grain RbAg4I5 films belongs to cubic crystal system. The principal x-ray diffraction peaks at d = 3.7447 and 1.8733 Å are related to the structure of ternary compound RbAg4I5 films.

  14. New process for preparing complex-shaped dielectric film similar to Mylar

    Science.gov (United States)

    Lagasse, R. R.; Kraynik, A. M.

    1982-02-01

    A new thermoforming/heat-treatment process yields complex-shaped dielectric film having electrical and shrinkage properties similar to those of flat Mylar film. This similarity should extend to other physical properties because the new process is directly analogous to the process used to prepare Mylar. Commercially available poly(ethylene terephthalate) film is formed into a cavity at approx. 110 C and then heat treated at approx. 180 C. A laboratory-scale forming apparatus has produced cylindrically shaped films having depth/diameter ratio approx. 1, a tapered wall-section, and variation in wall thickness of 3X. Evaluation of other forming methods suggest that the production rate and thickness uniformity can be improved with existing technology. Thermal shrinkage at 150 C, 1 kHz dielectric constant from -55 to +70 C, leakage current at 1 kV, and breakdown voltage have been measured for both the complex-shaped film and Mylar.

  15. Preparation and characterization of nanostructured ZnO thin films for photoelectrochemical splitting of water

    Indian Academy of Sciences (India)

    Monika Gupta; Vidhika Sharma; Jaya Shrivastava; Anjana Solanki; A P Singh; V R Satsangi; S Dass; Rohit Shrivastav

    2009-02-01

    Nanostructured zinc oxide thin films (ZnO) were prepared on conducting glass support (SnO2: F overlayer) via sol–gel starting from colloidal solution of zinc acetate 2-hydrate in ethanol and 2-methoxy ethanol. Films were obtained by spin coating at 1500 rpm under room conditions (temperature, 28–35°C) and were subsequently sintered in air at three different temperatures (400, 500 and 600°C). The evolution of oxide coatings under thermal treatment was studied by glancing incidence X-ray diffraction and scanning electron microscopy. Average particle size, resistivity and bandgap energy were also determined. Photoelectrochemical properties of thin films and their suitability for splitting of water were investigated. Study suggests that thin films of ZnO, sintered at 600°C are better for photoconversion than the films sintered at 400 or 500°C. Plausible explanations have been provided.

  16. The Preparation and Characterization of Amorphous SiCN Thin Films

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Radio Frequency plasma enhanced Chemical Vapor Deposition (RF CVD) using N2, SiH4 and C2H4 as the reaction sources was used to prepare amorphous ternary SixCyNz thin films. The chemical states of the C, Si and N atoms in the films were characterized by X-ray photoelectron spectroscopy (XPS) and Fourier Transform Infrared Spectroscopy (FTIR). The refractive index n, extinction coefficient k and optical band gap Eopt of the thin films were investigated by UV-visible spectrophotometer and spectroscopic ellipsometer.The results show that a complex chemical bonding network rather than a simple mixture of Si3N4,SiC,CNx and a-C etc. , may exist in the ternary thin films. The n's of the films are within the range of 1.90-2. 45, and Eopt's of all samples are within the range of 2.71 -2. 86 eV.

  17. Preparation of Ag-doped TiO2 Thin Film by Sol-gel Method

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The Ag-TiO2 thin film has been prepared on glass substrate by sol-gel process. The structure and properties of the materials were studied by DTA, XRD, and EPR.The photocatalytic activity was examined by the photocatalytic degradation of dichlorophos. The analysis results indicate that the photocatalytic activity of the Ag-TiO2 thin film is higher than that of pure TiO2 thin film. It is also influenced by the content of anatase and heating temperature. The ESR result shows that the Ag-TiO2 thin film has more hydroxide radicals than pure TiO2 thin film after illuminated by UV light.

  18. Preparation of γ-Al2O3 films by laser chemical vapor deposition

    Science.gov (United States)

    Gao, Ming; Ito, Akihiko; Goto, Takashi

    2015-06-01

    γ- and α-Al2O3 films were prepared by chemical vapor deposition using CO2, Nd:YAG, and InGaAs lasers to investigate the effects of varying the laser wavelength and deposition conditions on the phase composition and microstructure. The CO2 laser was found to mostly produce α-Al2O3 films, whereas the Nd:YAG and InGaAs lasers produced γ-Al2O3 films when used at a high total pressure. γ-Al2O3 films had a cauliflower-like structure, while the α-Al2O3 films had a dense and columnar structure. Of the three lasers, it was the Nd:YAG laser that interacted most with intermediate gas species. This promoted γ-Al2O3 nucleation in the gas phase at high total pressure, which explains the cauliflower-like structure of nanoparticles observed.

  19. ZnO THIN FILMS PREPARED BY SPRAY-PYROLYSIS TECHNIQUE FROM ORGANO-METALLIC PRECURSOR

    Directory of Open Access Journals (Sweden)

    Martin Mikulics

    2012-07-01

    Full Text Available Presented experiments utilize methanolic solution of zinc acetyl-acetonate as a precursor and sapphire (001 as a substrate for deposition of thin films of ZnO. The X-ray diffraction analysis revealed polycrystalline character of prepared films with preferential growth orientation along c-axis. The roughness of prepared films was assessed by AFM microscopy and represented by roughness root mean square (RMS value in range of 1.8 - 433 nm. The surface morphology was mapped by scanning electron microscopy showing periodical structure with several local defects. The optical transmittance spectrum of ZnO films was measured in wavelength range of 200-1000 nm. Prepared films are transparent in visible range with sharp ultra-violet cut-off at approximately 370 nm. Raman spectroscopy confirmed wurtzite structure and the presence of compressive stress within its structure as well as the occurrence of oxygen vacancies. The four-point Van der Pauw method was used to study the transport prosperities. The resistivity of presented ZnO films was found 8 × 10–2 Ω cm with carrier density of 1.3 × 1018 cm–3 and electron mobility of 40 cm2 V–1 s–1.

  20. Microstructural changes and effect of variation of lattice strain on positron annihilation lifetime parameters of zinc ferrite nanocomposites prepared by high enegy ball-milling

    Directory of Open Access Journals (Sweden)

    Abhijit Banerjee

    2012-12-01

    Full Text Available Zn-ferrite nanoparticles were synthesized at room temperature by mechanical alloying the stoichiometric (1:1 mol% mixture of ZnO and α-Fe2O3 powder under open air. Formation of both normal and inverse spinel ferrite phases was noticed after 30 minutes and 2.5 hours ball milling respectively and the content of inverse spinel phase increased with increasing milling time. The phase transformation kinetics towards formation of ferrite phases and microstructure characterization of ball milled ZnFe2O4 phases was primarily investigated by X-ray powder diffraction pattern analysis. The relative phase abundances of different phases, crystallite size, r.m.s. strain, lattice parameter change etc. were estimated from the Rietveld powder structure refinement analysis of XRD data. Positron annihilation lifetime spectra of all ball milled samples were deconvoluted with three lifetime parameters and their variation with milling time duration was explained with microstructural changes and formation of different phases with increase of milling time duration.

  1. Ruthenium disulfide thin films prepared by the successive ionic layer adsorption and reaction (SILAR) method

    Institute of Scientific and Technical Information of China (English)

    LIU Xiaoxin; JIN Zhengguo; ZHAO Juan; BU Shaojing

    2004-01-01

    RuS2 thin films were prepared by the cost-effective chemical method-successive ionic layer adsorption and reaction (SILAR). The structural, optical, and electrical properties were investigated using X-ray diffraction, scanning electron microscopy, optical transmittance, and electrical resistivity methods. The results indicate that the films are homogeneous and dense; the structure of the as-deposited fdms is amorphous and they crystallize after annealed at 500°C for 30 min. The band gap of the as-deposited films is found to be 1.85 eV, and the electrical resistivity of them is in the order of 105 Ω.cm.

  2. PREPARATION AND CHARACTERIZATION OF SOLUBLE EGGSHELL MEMBRANE PROTEIN/CHITOSAN BLEND FILMS

    Institute of Scientific and Technical Information of China (English)

    Qing-lei Qi; Qiang Li; Jian-wei Lu; Zhao-xia Guo; Jian Yu

    2009-01-01

    Biopolymer chitosan was used to modify the mechanical properties of soluble eggshell membrane protein (SEP) films. The SEP/chitosan blend films were prepared by solution casting from 10% aqueous acetic acid. Tensile strength and elongation at break of the blend films increased with increasing amount of chitosan. Microphase separation was observed by field emission scanning electron microscopy, although interaction between the two components was revealed by FTIR. The biocompatibility of SEP/chitosan blend flints containing 10%-50% of chitosan, as demonstrated by cell culture of NIH3T3, was much better than that of pure chitosan.

  3. Preparation and Characterization of Nano-ZnFe2O4/TiO2 Films

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The nano-ZnFe2O4/TiO2 films possess the functions of desulfurization and degradation for organic pollutants. The sols of ZnFe2O4/TiO2 were prepared by sol-gel method and coated on glass and porous ceramic by vertical coating and dipping-lift processes, respectively, and the samples were obtained after drying and sintering. The composition, appearance, absorption spectrum of the films,and the influence of the film on porous ceramic performances were analyzed using SEM, AFM, UVVis spectrometer, and mercury porosimeter, respectively, to determine the operation parameters of the multifunction porous ceramic elements for gas-purification.

  4. Photoelectric Characteristics of Nano TiO2 Film Prepared By Spraying Pyrolysis Method

    OpenAIRE

    Cuong Tran Kim

    2015-01-01

    The nanocrystalline TiO2 (nc TiO2) film was prepared by spraying pyrolysis method. Starting material for the synthesis was TiCl4. Phase compositions and crystalline sizes were examined by pattern of XRD, and surface morphology of the thin film was analyzed by SEM and AFM. Optical characteristics were examined by UV – Vis and luminescent spectra (PL). Electric characteristics were examined by measuring resistance changing of films versus temperature. The experimental data ...

  5. Preparation of Composite Films of a Conjugated Polymer and C60NWs and Their Photovoltaic Application

    OpenAIRE

    Takatsugu Wakahara; Kun’ichi Miyazawa; Osamu Ito; Nobutaka Tanigaki

    2016-01-01

    Composite films of conjugated polymers, such as poly[2-methoxy-5-(3′,7′-dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV) and poly(3-hexylthiophene) (P3HT), with C60 nanowhiskers (C60NWs) were prepared. The photoluminescence originating from the conjugated MDMO-PPV polymers was effectively quenched in the composite film, indicating a strong interaction between the conjugated polymer and C60NWs. The photovoltaic devices were fabricated using C60NW (conjugated polymer) composite films, result...

  6. Preparation of Composite Films of a Conjugated Polymer and C60NWs and Their Photovoltaic Application

    OpenAIRE

    Takatsugu Wakahara; Kun’ichi Miyazawa; Osamu Ito; Nobutaka Tanigaki

    2016-01-01

    Composite films of conjugated polymers, such as poly[2-methoxy-5-(3′,7′-dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV) and poly(3-hexylthiophene) (P3HT), with C60 nanowhiskers (C60NWs) were prepared. The photoluminescence originating from the conjugated MDMO-PPV polymers was effectively quenched in the composite film, indicating a strong interaction between the conjugated polymer and C60NWs. The photovoltaic devices were fabricated using C60NW (conjugated polymer) composite films, result...

  7. Electrochemical preparation and abnormal infrared effects of nanostructured Ni thin film

    Institute of Scientific and Technical Information of China (English)

    WANG Hanchun; ZHOU Zhiyou; TANG Wei; YAN Jiawei; SUN Shigang

    2004-01-01

    Nanometer-scale thin film of Ni supported on glassy carbon (nm-Ni/GC) was prepared by electrochemical deposition through cyclic voltammetry (CV). The properties of nm-Ni/GC were studied by electrochemical in situ FTIR reflection spectroscopy using CO adsorption as probe reaction. It has revealed that the nm-Ni/GC exhibits abnormal infrared effects (AIREs). The study has extended the investigation of the AIREs that we have discovered initially on nanostruetured film materials of platinum group metals and alloys to nanostructured film materials of iron group metals.

  8. Preparation of Poly (ethylene oxide) (PEO) Modified Tungsten Oxide Hybrid Films via Sol-Gel Processing

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Poly (ethylene axide) (PEO) modified WO3 thin films were prepared on glass substrates with special temperature.The sol-gel transition proess was investigated by using DTA-TG,SEM and XRD.The electrochemical characteristic of the films was studied by cyclic voltmmetry measurement.The results show that PEO has heavy effects on the crystallization of WO3 during structure evolution because of the interaction between PEO and WO3.It increases the crystallization temperature of the gels and thus improves the electrochemical properties and cyclic life of WO3 film as electrochromic materials.

  9. Ultrasonically assisted intercalation of Ni in Al2O3 thin film prepared by SILAR technique

    Science.gov (United States)

    Dhanayat, Swapnali; Digraskar, Renuka; Gattu, Ketan; Upadhye, Deepak; Mahajan, Sandeep; Sharma, Ramphal; Ghule, Anil

    2013-06-01

    The Al2O3 thin film were prepared by successive ionic layer adsorption and reaction (SILAR) technique and annealed at 250 °C. Thereafter, Ni was ultrasonically intercalated in Al2O3 thin films for different sonication time period of 5 and 10s, and subsequently annealed at 250 °C to form NiO-Al2O3. The films were further characterized using scanning electron microscopy, energy dispersive X-ray analysis, UV-Vis spectrophotometer and I-V system, to study morphological, compositional, optical and electrical properties.

  10. Preparation of properties of SWNT/graphene oxide type flexible transparent conductive films.

    Science.gov (United States)

    Kim, Jin Ho; Jung, Jae Mok; Kwak, Jun Young; Jeong, Jung Hyun; Choi, Byung Chun; Lim, Kwon Taek

    2011-08-01

    Single walled carbon nanotube (SWNT)/graphene oxide (GO) hybrid films were prepared by a facile bar coating method on a polyethylene terephthalate substrate using a mixed solution of SWCNTs and GO. An acryl type polymer was employed as a dispersion agent to obtain SWCNT and GO suspension in ethyl alcohol. The SWCNT/GO hybrid films were highly transparent and electrically conductive, showing 80% transmittance and 1.8 x 10(3) ohm/sq surface resistance. The surface resistance of the SWCNT/GO film could be further improved to 750 ohm/sq by hydrazine vapor reduction.

  11. A New Approach for Preparing Effective Inhibition Film on Copper Based on Self-assembled Process

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A new method for preparing effective inhibition film on copper has been developed. Phenylthiourea (PT) was first absorbed to copper surface to form a monolayer. 1-Dodecanethiol (DT) was then assembled on the surface for modification. Finally, AC voltage was loaded on copper covered the mixed film to improve it further. After these processes, an effective inhibition film was gained because of its high charge transfer resistance and low corrosion current density shown in electrochemical impedance spectra and polarization. The inhibition efficiency was more than 97%.

  12. Electrical and optical properties of CZTS thin films prepared by SILAR method

    OpenAIRE

    2016-01-01

    In the present work, Cu2ZnSnS4 (CZTS) thin film was deposited onto the glass substrate by simple and economic SILAR method and its structural, morphological, optical and electrical properties were analyzed. X-ray diffraction (XRD) analysis confirms the formation of CZTS with kesterite structure and the average crystallite size is found to be 142 nm. Scanning electron microscope (SEM) image shows that the film has homogeneous, agglomerated surface without any cracks. The prepared CZTS film sho...

  13. Preparation and characterization of bionanocomposite film based ontapioca starch/bovine gelatin/nanorod zinc oxide

    DEFF Research Database (Denmark)

    Mehdi Marvizadeh, Mohammad; Oladzadabbasabadi, Nazila; Mohammadi Nafchi, Abdorreza

    2017-01-01

    To exploring a nano-packaging materials for using as coating or edible films, tapioca starch/gelatin/nanorod ZnO (ZnOsingle bondN) bionanocomposites were prepared via solution casting technique. The effects of nanofiller addition on the mechanical, physicochemical, and crystalline structures.......5% ZnOsingle bondN into biopolymer matrix. In summary combined starch/gelatin films supported by ZnOsingle bondN showed better properties compared to starch or gelatin alone. Thus, the bionanocomposite films can be used in food, medicine, and pharmaceutical packaging....

  14. Preparation of polycrystalline CdS thin films by chemical bath deposition

    Energy Technology Data Exchange (ETDEWEB)

    Lee, E.A.; Kim, B.S.; Shin, S.H.; Park, J.I.; Park, K.J. [National Industrial Technology Inst., Kwacheon (Korea, Republic of). Div. of Inorganic Chemistry

    1996-12-31

    CdS has been recognized as a promising n-type window material for CdTe/CdS and CuInSe{sub 2}/CdS heterojunction thin film solar cells. The authors prepared CdS thin films from a solution containing cadmium acetate, thiourea, ammonia, and ammonium acetate. They varied fabrication conditions such as the concentrations of reactants, reaction temperature, and heat treatment, to investigate the changes in structural and optical properties of the film. Effects of substrate on the properties were also investigated.

  15. Chemical Structure of Carbon Nitride Films Prepared by MW-ECR Plasma Enhanced Magnetron Sputtering

    Institute of Scientific and Technical Information of China (English)

    XUJun,GAOPeng; DINGWan-yu; LIXin; DENGXin-lu; DONGChuang

    2004-01-01

    Amorphous carbon nitride thin films were prepared by plasma-enhanced DC magnetron sputtering using twinned microwave electron cyclotron resonance plasma sources. Chemical structure of deposited films was investigated using X-ray photoelectron spectroscopy and Fourier transtorm infrared spectroscopy. The results indicate that the deposition rate is strongly affected by direct current bias, and the films are mainly composed of a single amorphous carbon nitride phase with N/C ratio close to C3N4, and the bonding is predominantly of C-N type.

  16. STUDY ON Ni-Cr SYSTEM SOLAR SELECTIVE THIN FILMS PREPARED BY MAGNETRON REACTIVE SPUTTERING PROCESS

    Institute of Scientific and Technical Information of China (English)

    B.W. Wang; H. Shen

    2002-01-01

    Ni-Cr System solar selective thin solid films were prepared by d.c. magnetron reactivesputtering under the atmosphere of O2 and N2. Ni-Cr alloy was chosen as targetmaterial and copper sheets as substrate. Using SEM, Spectrophotometer and Talystepto analyze the relations between the selective characteristic and the structure, theformation and the thickness of the thin films. The aim is to obtain good solar selectivethin films with high absorptance and low emittance, which is applied to flat plate solarheat collectors.

  17. Regenerated cellulose/halloysite nanotube nanocomposite films prepared with an ionic liquid

    Energy Technology Data Exchange (ETDEWEB)

    Soheilmoghaddam, Mohammad [Department of Polymer Engineering, Faculty of Chemical Engineering, Universiti Teknologi Malaysia (UTM), Johor (Malaysia); Wahit, Mat Uzir, E-mail: mat.uzir@cheme.utm.my [Center for Composites, Universiti Teknologi Malaysia (UTM), 81310 Skudai, Johor (Malaysia); Mahmoudian, Shaya [Department of Textile Engineering, Kashan Branch, Islamic Azad University, Kashan (Iran, Islamic Republic of); Hanid, Nurbaiti Abdul [Department of Polymer Engineering, Faculty of Chemical Engineering, Universiti Teknologi Malaysia (UTM), Johor (Malaysia)

    2013-09-16

    Regenerated cellulose/halloysite nanotube (RC/HNT) nanocomposite films were successfully prepared in ionic liquid, 1-butyl-3-methylimidazolium chloride (BMIMCl) using solution casting method. The structural, morphological, thermal and mechanical properties of RC/HNT nanocomposites were investigated. X-ray diffraction analysis revealed a cellulose II crystalline structure and well dispersed HNT in RC/HNT nanocomposite films. At 6 wt.% HNT film, tensile strength and Young's modulus of RC films improved by 55.3% and 100%, respectively. Moisture absorption by the nanocomposites in an environment with 75% constant relative humidity was reduced by the addition of HNT to the RC. The presence of HNT enhanced the thermal stability and char yield of RC. The significant reinforcing effects of HNTs demonstrated that there is a possible interface interaction between cellulose and HNT which yielded better thermal and mechanical properties of the nanocomposite films as compared to pure RC. - Highlights: • The RC/HNT nanocomposite films were prepared via ionic liquid, BMIMCl. • XRD diffraction patterns and FESEM revealed well dispersed HNT in cellulose matrix. • The nanocomposite films exhibited excellent mechanical properties. • Moisture absorption and diffusion coefficient of RC reduced by HNT incorporation. • Addition of HNT enhanced thermal stability and activation energy of the RC.

  18. Antimicrobial activity of thin solid films of silver doped hydroxyapatite prepared by sol-gel method.

    Science.gov (United States)

    Iconaru, Simona Liliana; Chapon, Patrick; Le Coustumer, Philippe; Predoi, Daniela

    2014-01-01

    In this work, the preparation and characterization of silver doped hydroxyapatite thin films were reported and their antimicrobial activity was characterized. Silver doped hydroxyapatite (Ag:HAp) thin films coatings substrate was prepared on commercially pure Si disks by sol-gel method. The silver doped hydroxyapatite thin films were characterized by various techniques such as Scanning electron microscopy (SEM) with energy Dispersive X-ray attachment (X-EDS), Fourier transform infrared spectroscopy (FT-IR), and glow discharge optical emission spectroscopy (GDOES). These techniques have permitted the structural and chemical characterisation of the silver doped hydroxyapatite thin films. The antimicrobial effect of the Ag:HAp thin films on Escherichia coli and Staphylococcus aureus bacteria was then investigated. This is the first study on the antimicrobial effect of Ag:HAp thin films obtained by sol-gel method. The results of this study have shown that the Ag:HAp thin films with x(Ag) = 0.5 are effective against E. coli and S. aureus after 24 h.

  19. Antimicrobial Activity of Thin Solid Films of Silver Doped Hydroxyapatite Prepared by Sol-Gel Method

    Directory of Open Access Journals (Sweden)

    Simona Liliana Iconaru

    2014-01-01

    Full Text Available In this work, the preparation and characterization of silver doped hydroxyapatite thin films were reported and their antimicrobial activity was characterized. Silver doped hydroxyapatite (Ag:HAp thin films coatings substrate was prepared on commercially pure Si disks by sol-gel method. The silver doped hydroxyapatite thin films were characterized by various techniques such as Scanning electron microscopy (SEM with energy Dispersive X-ray attachment (X-EDS, Fourier transform infrared spectroscopy (FT-IR, and glow discharge optical emission spectroscopy (GDOES. These techniques have permitted the structural and chemical characterisation of the silver doped hydroxyapatite thin films. The antimicrobial effect of the Ag:HAp thin films on Escherichia coli and Staphylococcus aureus bacteria was then investigated. This is the first study on the antimicrobial effect of Ag:HAp thin films obtained by sol-gel method. The results of this study have shown that the Ag:HAp thin films with xAg=0.5 are effective against E. coli and S. aureus after 24 h.

  20. Preparation of silica films on Ru(0001): A LEEM/PEEM study

    Science.gov (United States)

    Klemm, H. W.; Peschel, G.; Madej, E.; Fuhrich, A.; Timm, M.; Menzel, D.; Schmidt, Th.; Freund, H.-J.

    2016-01-01

    We use an aberration corrected spectro-microscope, the low energy electron microscope/photoelectron emission microscope (LEEM/PEEM) SMART, to follow the preparation and structure of a bilayer silica film on Ru(0001) as a function of temperature and oxidation conditions. This allows us to analyze the growth process at different length scales in order to judge on the overall quality and the morphology of the film. It is found that the film growth occurs in a crystalline and a vitreous phase as previously discovered using scanning tunneling microscopy. However, the present experiment allows an analysis on the sub-micron level to gain insight into the growth process at a mesoscopic scale. We find that the fully oxidized film can be prepared but that this film contains holes. These are unavoidable and are important to consider, if one wants to use the films for ensemble averaging experiments to investigate migration and reaction of molecules between the silica film and the Ru(0001) substrate.

  1. Preparation and characterization of nanostructured Pt/TiO2 thin films treated using electron beam.

    Science.gov (United States)

    Shin, Joong-Hyeok; Woo, Hee-Gweon; Kim, Bo-Hye; Lee, Byung Cheol; Jun, Jin

    2010-05-01

    Pt nanoparticle-doped titanium dioxide (Pt/TiO2) thin films were prepared on a silicon wafer substrate by sol-gel spin coating process. The prepared thin films were treated with electron beam (EB at 1.1 MeV, 100, 200, 300 kGy) at air atmosphere. The effect of EB-irradiation on the composition of the treated thin films, optical properties and morphology of thin films were investigated by various analytical techniques such as X-ray photoelectron spectroscopy (XPS), spectroscopic ellipsometry (SE), X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The crystal structure of the TiO2 layer was found to be an anatase phase and the size of TiO2 particles was determined to be about 13 nm. Pt nanoparticles with diameter of 5 nm were observed on surface of the films. A new layer (presumed to be Pt-Ti complex and/or PtO2 compound) was created in the Pt/TiO2 thin film treated with EB (300 kGy). The transmittance of thin film decreased with EB treatment whereas the refractive index increased.

  2. Preparation and characterization of gamma irradiated Starch/PVA/ZnO nanocomposite films

    Science.gov (United States)

    Akhavan, Azam; Khoylou, Farah; Ataeivarjovi, Ebrahim

    2017-09-01

    In this study starch/PVA/ZnO nanocomposite films with antibacterial activity were prepared and modified using gamma irradiation for packaging applications. ZnO nanoparticles (NPs) were synthesized from Zn(OH)2 using hydrothermal process and characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The prepared ZnO NPs were incorporated into blend films of starch and poly (vinyl alcohol) (PVA) with different concentrations from 0.1 to 1 wt% using solution casting method. The results of SEM confirmed good dispersion of ZnO NPs into the films while FTIR spectroscopy showed interactions between ZnO particles and starch/PVA blend. The nanocomposite films were irradiated at the dose range of 1-5 kGy. It was found that gamma irradiation induces a significant reduction in water absorptions of the films at the dose of 3 kGy. Different trends were observed for the tensile and elongation properties of the irradiated films. Based on the results, the bacterial growth on the films was effectively inhibited when the dosage of ZnO NPs was only 0.5 wt%.

  3. The structure of Cu-Al films prepared by unbalanced DC magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Musil, J.; Bell, A.J. [Czech Acad. of Sci., Prague (Czech Republic). Inst. of Phys.; Chepera, M.; Zeman, J. [Military Technical Institute, PO Box 574, 602 00 (Czech Republic)

    1997-11-25

    Recently, the formation of nanostructured and amorphous materials has been the focus of intense research owing to interest from a basic scientific point of view and their potential technological value. This paper reports on the variation in, and control of, the structure of Cu-Al films prepared in a state-of-the-art unbalanced DC magnetron sputtering system. The structure is shown to be considerably influenced by ion bombardment during growth with both the energy and ratio of impinging ions: arriving atoms playing dominant roles. In addition, the addition of different quantities of Al to the thin film is shown to have a dramatic impact on the structure. The conditions under which nanocrystalline Cu-Al films can be prepared are given. The films were deposited by the magnetron sputter ion plating (MSIP) process using negative substrate biases up to 1000 V and at different argon pressures down to 0.04 Pa. The structure of the films were determined from XRD analyses. An attempt to correlate obtained XRD spectra with the structure of the film is suggested. The resistivities of the films were measured using the four-point probe method, whilst the content of Al was determined from EDX measurements. (orig.) 15 refs.

  4. Fe-doped epitaxial YBCO films prepared by chemical solution deposition

    Institute of Scientific and Technical Information of China (English)

    Hong Zhang; Yong Zhao; Wentao Wang; Min Pan; Ming Lei

    2014-01-01

    YBa2Cu3O7-d (YBCO)-coated conductors have wide-ranging potential in large-scale applications such as superconducting maglev trains and superconducting elec-tric cables, but low current carrying capability restrains the practical application of YBCO-coated conductors at high temperatures and high magnetic fields. It is crucial to develop YBCO-coated conductors with high critical cur-rent density. In this paper, epitaxial, dense, smooth, and crack-free Fe-doped YBCO films were prepared on a LaAlO3 single crystal substrate via a fluorine-free polymer-assisted metal organic deposition method. The effects of the dilute Fe doping on microstructure and superconduc-ting character of YBCO films were investigated. The crit-ical temperature for superconducting of the Fe-doped YBCO films decreases slightly. However, the in-field critical current density of YBCO films improves with dilute Fe doping of amounts less than x=0.005, compared to the pure YBCO film. Therefore, the current carrying capability of YBCO film can improve by doping with appropriate amounts of Fe. This means that dilute Fe doping in YBCO films may be a feasible way to prepare high-performance coated conductors.

  5. Structural and magnetic properties of Ni{sub 0.15}Mg{sub 0.1}Cu{sub 0.3}Zn{sub 0.45}Fe{sub 2}O{sub 4} ferrite prepared by NaOH-precipitation method

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Wei-xiao; Wang, Zhi, E-mail: zhiwang@tju.edu.cn

    2015-09-15

    Highlights: • NiMgCuZn ferrites were successfully prepared by low-temperature sintering. • NiMgCuZn ferrites have the advantages of both NiCuZn and MgCuZn ferrites. • NiMgCuZn ferrites exhibit high Curie temperature & high stability of permeability. - Abstract: The Ni{sub 0.15}Mg{sub 0.1}Cu{sub 0.3}Zn{sub 0.45}Fe{sub 2}O{sub 4} ferrite powders have been prepared by NaOH co-precipitation method and characterized by X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). The XRD patterns confirm the single phase spinel structure of synthesized nanoparticles. The average crystallite size of the particles increases from 12 to 36 nm with calcining temperature (T{sub a}) from 500 to 800 °C. The saturation magnetization (M{sub s}) of the superparamagnetic particles was deduced by Langevin theory. Subsequently, the densification characteristics and magnetic properties of the low-temperature 950 °C-sintered ferrite bulk samples were also investigated. The magnetic measurement showed that the sintered bulk sample of T{sub a} = 600 °C has the highest initial permeability (μ{sub i}), lowest coercivity (H{sub c}), largest saturation magnetization (M{sub s}) and satisfactory thermal stability of μ{sub i}. The microstructures of sintered samples were examined using field emission scanning electric microscope (FESEM). The T{sub a} has significant influence on the bulk density, initial permeability, saturation magnetization and coercivity of Ni{sub 0.15}Mg{sub 0.1}Cu{sub 0.3}Zn{sub 0.45}Fe{sub 2}O{sub 4} ferrite.

  6. High quality antireflective ZnS thin films prepared by chemical bath deposition

    Energy Technology Data Exchange (ETDEWEB)

    Tec-Yam, S.; Rojas, J.; Rejon, V. [Centro de Investigacion y de Estudios Avanzados del IPN, Unidad Merida, Departamento de Fisica Aplicada, Km. 6 Antigua Carretera a Progreso, AP 73-Cordemex, 97310 Merida Yucatan (Mexico); Oliva, A.I., E-mail: oliva@mda.cinvestav.mx [Centro de Investigacion y de Estudios Avanzados del IPN, Unidad Merida, Departamento de Fisica Aplicada, Km. 6 Antigua Carretera a Progreso, AP 73-Cordemex, 97310 Merida Yucatan (Mexico)

    2012-10-15

    Zinc sulfide (ZnS) thin films for antireflective applications were deposited on glass substrates by chemical bath deposition (CBD). Chemical analysis of the soluble species permits to predict the optimal pH conditions to obtain high quality ZnS films. For the CBD, the ZnCl{sub 2}, NH{sub 4}NO{sub 3}, and CS(NH{sub 2}){sub 2} were fixed components, whereas the KOH concentration was varied from 0.8 to 1.4 M. Groups of samples with deposition times from 60 to 120 min were prepared in a bath with magnetic agitation and heated at 90 Degree-Sign C. ZnS films obtained from optimal KOH concentrations of 0.9 M and 1.0 M exhibited high transparency, homogeneity, adherence, and crystalline. The ZnS films presented a band gap energy of 3.84 eV, an atomic Zn:S stoichiometry ratio of 49:51, a transmittance above 85% in the 300-800 nm wavelength range, and a reflectance below 25% in the UV-Vis range. X-ray diffraction analysis revealed a cubic structure in the (111) orientation for the films. The thickness of the films was tuned between 60 nm and 135 nm by controlling the deposition time and KOH concentration. The incorporation of the CBD-ZnS films into ITO/ZnS/CdS/CdTe and glass/Mo/ZnS heterostructures as antireflective layer confirms their high optical quality. -- Highlights: Black-Right-Pointing-Pointer High quality ZnS thin films were prepared by chemical bath deposition (CBD). Black-Right-Pointing-Pointer Better CBD-ZnS films were achieved by using 0.9 M-KOH concentration. Black-Right-Pointing-Pointer Reduction in the reflectance was obtained for ZnS films used as buffer layers.

  7. Preparation of chitosan films using different neutralizing solutions to improve endothelial cell compatibility.

    Science.gov (United States)

    He, Qing; Ao, Qiang; Gong, Yandao; Zhang, Xiufang

    2011-12-01

    The development of chitosan-based constructs for application in large-size defects or highly vascularized tissues is still a challenging issue. The poor endothelial cell compatibility of chitosan hinders the colonization of vascular endothelial cells in the chitosan-based constructs, and retards the establishment of a functional microvascular network following implantation. The aim of the present study is to prepare chitosan films with different neutralization methods to improve their endothelial cell compatibility. Chitosan salt films were neutralized with either sodium hydroxide (NaOH) aqueous solution, NaOH ethanol solution, or ethanol solution without NaOH. The physicochemical properties and endothelial cell compatibility of the chitosan films were investigated. Results indicated that neutralization with different solutions affected the surface chemistry, swelling ratio, crystalline conformation, nanotopography, and mechanical properties of the chitosan films. The NaOH ethanol solution-neutralized chitosan film (Chi-NaOH/EtOH film) displayed a nanofiber-dominant surface, while the NaOH aqueous solution-neutralized film (Chi-NaOH/H(2)O film) and the ethanol solution-neutralized film (Chi-EtOH film) displayed nanoparticle-dominant surfaces. Moreover, the Chi-NaOH/EtOH films exhibited a higher stiffness as compared to the Chi-NaOH/H(2)O and Chi-EtOH films. Endothelial cell compatibility of the chitosan films was evaluated with a human microvascular endothelial cell line, HMEC-1. Compared with the Chi-NaOH/H(2)O and Chi-EtOH films, HMECs cultured on the Chi-NaOH/EtOH films fully spread and exhibited significantly higher levels of adhesion and proliferation, with retention of the endothelial phenotype and function. Our findings suggest that the surface nanotopography and mechanical properties contribute to determining the endothelial cell compatibility of chitosan films. The nature of the neutralizing solutions can affect the physicochemical properties and

  8. Preparation of yttria-stabilized zirconia films for solid oxide fuel cells by electrophoretic deposition method

    Energy Technology Data Exchange (ETDEWEB)

    Ishihara, Tatsumi; Sato, Keiji; Mizuhara, Yukako; Takita, Yusaku (Oita Univ. (Japan). Faculty of Engineering)

    1992-06-01

    The electrophoretic deposition (EPD) method was applied for the preparation of yttria-stabilized zirconia (YSZ) films for a solid oxide fuel cell (SOFC). Dense YSZ films with uniform thickness can be readily prepared by EPD method. When the planar SOFC was fabricated by using La[sub 0.6]Sr[sub 0.4]MnO[sub 3] as a cathode and electroless plating Pt as an anode, the open circuit voltage and the maximum power density attained were 1.03 V and 1.87 W cm[sup -2], respectively. (author).

  9. Electrical properties of silver selenide thin films prepared by reactive evaporation

    Indian Academy of Sciences (India)

    M C Santhosh Kumar; B Pradeep

    2002-10-01

    The electrical properties of silver selenide thin films prepared by reactive evaporation have been studied. Samples show a polymorphic phase transition at a temperature of 403 ± 2 K. Hall effect study shows that it has a mobility of 2000 cm2V–1s–1 and carrier concentration of 1018 cm–3 at room temperature. The carriers are of -type. X-ray diffraction study indicates that the as-prepared films are polycrystalline in nature. The lattice parameters were found to be = 4.353 Å, = 6.929 Å and = 7.805 Å.

  10. [Study on the Properties of the Pc-Si Films Prepared by Magnetron Co-Sputtering at Low Temperature].

    Science.gov (United States)

    Duan, Liang-fei; Yang, Wen; Zhang, Li-yuan; Li, Xue-ming; Chen, Xiao-bo; Yang, Pei-zhi

    2016-03-01

    The polycrystalline silicon thin films play an important role in the field of electronics. In the paper, α-SiAl composite membranes on glass substrates was prepared by magnetron co-sputtering. The contents of Al radicals encapsulated-in the α-Si film can be adjusted by changing the Al to Si sputtering power ratios. The as-prepared α-Si films were converted into polycrystalline films by using a rapid thermal annealing (RTP) at low temperature of 350 degrees C for 10 minutes in N2 atmosphere. An X-ray diffractometer, and Raman scattering and UV-Visible-NIR Spectrometers were used to characterize the properties of the Pc-Si films. The influences of Al content on the properties of the Pc-Si films were studied. The results showed that the polycrystalline silicon films were obtained from α-SiAl composite films which were prepared by magnetron co-sputtering at a low temperature following by a rapid thermal annealing. The grain size and the degree of crystallization of the Pc-Si films increased with the increase of Al content, while the optical band gap was reduced. The nc-Si films were prepared when the Al to Si sputtering power ratio was 0.1. And a higher Crystallization rate (≥ 85%) of polycrystalline silicon films were obtained when the ratio was 0.3. The band gaps of the polycrystalline silicon films can be controlled by changing the aluminum content in the films.

  11. CO responses of sensors based on cerium oxide thick films prepared from clustered spherical nanoparticles.

    Science.gov (United States)

    Izu, Noriya; Matsubara, Ichiro; Itoh, Toshio; Akamatsu, Takafumi; Shin, Woosuck

    2013-03-08

    Various types of CO sensors based on cerium oxide (ceria) have been reported recently. It has also been reported that the response speed of CO sensors fabricated from porous ceria thick films comprising nanoparticles is extremely high. However, the response value of such sensors is not suitably high. In this study, we investigated methods of improving the response values of CO sensors based on ceria and prepared gas sensors from core-shell ceria polymer hybrid nanoparticles. These hybrid nanoparticles have been reported to have a unique structure: The core consists of a cluster of ceria crystallites several nanometers in size. We compared the characteristics of the sensors based on thick films prepared from core-shell nanoparticles with those of sensors based on thick films prepared from conventionally used precipitated nanoparticles. The sensors prepared from the core-shell nanoparticles exhibited a resistance that was ten times greater than that of the sensors prepared from the precipitated nanoparticles. The response values of the gas sensors based on the core-shell nanoparticles also was higher than that of the sensors based on the precipitated nanoparticles. Finally, improvements in sensor response were also noticed after the addition of Au nanoparticles to the thick films used to fabricate the two types of sensors.

  12. Preparation of ion-exchange thin film using plasma processes. Plasma process wo mochiita ion kokansei usumaku no sakusei

    Energy Technology Data Exchange (ETDEWEB)

    Ogumi, Z.; Uchimoto, Y. (Kyoto University, Kyoto (Japan). Faculty of Engineering)

    1992-10-31

    The present report describes a study which aims at preparation of a new functional film by plasma polymerization. For this purpose, 4-vinylpyridine monomer is plasma-polymerized to obtain a thin film, which is quaternarized with 1-bromopropane to produce an anion exchange thin film, which is laminated on the surface of a cation-exchange film to make a mono-valent cation perm-selective film. In plasma-polymerization, the relations of polymerizing pressure, as parameter, to the deposition rate of the polymerizerd film and the characteristics of compound were clarified. In preparing the anion-exchange thin film, the preparation of uniform ultrathin films with no pinhole was attempted. For this purpose, the transference number of Cl[sup -] was measured so as to confirm that Cl[sup -] is uniformly distributed and fixed cation groups are distributed uniformly in the film. The perm-selective film exhibited a high mono-valent cation perm-selectivity while its film resistance was increased. This increase is found to be broken down to the resistance of the plasma-polymerization film layer and the resistance of the film interface. The latter arises from the implantation of nitrogen-cointaining species in the plasma onto the surface of the cation exchange film. 26 refs., 10 figs., 2 tabs.

  13. Preparation and optical properties of ZnSe films

    Directory of Open Access Journals (Sweden)

    E.M. Sofronova

    2012-12-01

    Full Text Available Microwave method was used for the synthesis and purification of the initial zinc selenide salt. The obtaining powder was used for deposition of the ZnSe thin films on the ultrasonically cleaned glass substrates using the quasi-closed space evaporation under the following conditions: the constant evaporation temperature Te = 800 °C, the temperature of the substrate Ts = 100-600 °C. The investigation of optical characteristics allow to calculate the band gap of condensates and specify their phase composition.

  14. Structural characterization of supported nanocrystalline ZnO thin films prepared by dip-coating

    Energy Technology Data Exchange (ETDEWEB)

    Casanova, J.R. [CITEDEF-CINSO-CONICET Centro de Investigaciones en Solidos, Juan B. de La Salle 4397, B1603ALO, Villa Martelli, Buenos Aires (Argentina); Heredia, E.A., E-mail: eheredia@citedef.gob.ar [CITEDEF-CINSO-CONICET Centro de Investigaciones en Solidos, Juan B. de La Salle 4397, B1603ALO, Villa Martelli, Buenos Aires (Argentina); Bojorge, C.D.; Canepa, H.R. [CITEDEF-CINSO-CONICET Centro de Investigaciones en Solidos, Juan B. de La Salle 4397, B1603ALO, Villa Martelli, Buenos Aires (Argentina); Kellermann, G. [Departamento de Fisica, Universidade Federal do Parana, Curitiba, PR (Brazil); Craievich, A.F. [Instituto de Fisica, Universidade de Sao Paulo, Cidade Universitaria, Sao Paulo, SP (Brazil)

    2011-09-15

    Nanocrystalline ZnO thin films prepared by the sol-gel dip-coating technique were characterized by grazing incidence X-ray diffraction (GIXD), atomic force microscopy (AFM), X-ray reflectivity (XR) and grazing incidence small-angle X-ray scattering (GISAXS). The structures of several thin films subjected to (i) isochronous annealing at 350, 450 and 550 deg. C, and (ii) isothermal annealing at 450 deg. C during different time periods, were characterized. The studied thin films are composed of ZnO nanocrystals as revealed by analysing several GIXD patterns, from which their average sizes were determined. Thin film thickness and roughness were determined from quantitative analyses of AFM images and XR patterns. The analysis of XR patterns also yielded the average density of the studied films. Our GISAXS study indicates that the studied ZnO thin films contain nanopores with an ellipsoidal shape, and flattened along the direction normal to the substrate surface. The thin film annealed at the highest temperature, T = 550 deg. C, exhibits higher density and lower thickness and nanoporosity volume fraction, than those annealed at 350 and 450 deg. C. These results indicate that thermal annealing at the highest temperature (550 deg. C) induces a noticeable compaction effect on the structure of the studied thin films.

  15. Surface modification of silicon-containing fluorocarbon films prepared by plasma-enhanced chemical vapor deposition

    Science.gov (United States)

    Jin, Yoonyoung; Desta, Yohannes; Goettert, Jost; Lee, G. S.; Ajmera, P. K.

    2005-07-01

    Surface modification of silicon-containing fluorocarbon (SiCF) films achieved by wet chemical treatments and through x-ray irradiation is examined. The SiCF films were prepared by plasma-enhanced chemical vapor deposition, using gas precursors of tetrafluoromethane and disilane. As-deposited SiCF film composition was analyzed by x-ray photoelectron spectroscopy. Surface modification of SiCF films utilizing n-lithiodiaminoethane wet chemical treatment is discussed. Sessile water-drop contact angle changed from 95°+/-2° before treatment to 32°+/-2° after treatment, indicating a change in the film surface characteristics from hydrophobic to hydrophilic. For x-ray irradiation on the SiCF film with a dose of 27.4 kJ/cm3, the contact angle of the sessile water drop changed from 95°+/-2° before radiation to 39°+/-3° after x-ray exposure. The effect of x-ray exposure on chemical bond structure of SiCF films is studied using Fourier transform infrared measurements. Electroless Cu deposition was performed to test the applicability of the surface modified films. The x-ray irradiation method offers a unique advantage in making possible surface modification in a localized area of high-aspect-ratio microstructures. Fabrication of a Ti-membrane x-ray mask is introduced here for selective surface modification using x-ray irradiation.

  16. Zinc oxide films prepared by sol-gel spin-coating

    Energy Technology Data Exchange (ETDEWEB)

    Natsume, Y.; Sakata, H. [Tokai Univ., Hiratsuka, Kanagawa (Japan). Dept. of Appl. Chem.

    2000-08-22

    The d.c. electrical conductivity and optical properties of undoped zinc oxide films prepared by the sol-gel process using a spin-coating technique were investigated. The ZnO films were obtained by 10 cycle spin-coated and dried zinc acetate films followed by annealing in air at 500-575 C. The films deposited on the Pyrex glass substrate were polycrystalline and c-axis oriented. A minimum film resistivity gave 28.2 {omega} cm at an annealing temperature of 525 C. The temperature dependence of the conductivity indicated electron transport in the conduction band due to thermal excitation of donor electrons for temperatures from 250 to 300 K. The grain boundary scattering effect due to thermionic emission was confirmed. For temperatures below 250 K nearest-neighbor hopping conduction was dominant in the films. The films were transparent in the visible range above 400 nm and had sharp ultraviolet absorption edges at 380 nm. The absorption edge analysis revealed that the optical band gap energy for the films was 3.20-3.21 eV and the electronic transition was of the direct transition type. From the Urbach tail analysis the width of the localized state E{sub e}=0.07-0.08 eV. (orig.)

  17. Study on AlSb Polycrystalline Thin Films Prepared by Vacuum Co-Evaporation

    Science.gov (United States)

    Song, Huijin; Wu, Lili; Zheng, Jiagui; Feng, Lianghuan; Lei, Zhi; Zhang, Jingquan

    In this paper, the AlSb polycrystalline thin films were prepared by vacuum co-evaporation technology and their structural, optical and electrical properties have been studied. XRD results showed that the as-deposited AlSb amorphous thin films transformed to polycrystalline state after annealed in vacuum at temperatures higher than 540°C. The process of phase change was observed to depend on the annealing temperature and the film composition. Some irreversible changes took place in the annealed films during the measurement of the temperature dependence of the film conductance. The conductance activation energy of the film was 0.132 and 0.32 eV during the heating and cooling process, respectively, which suggests the decrease of Sb vacancies in the AlSb film after the heating. Hall effect and optical absorption measurement showed that the AlSb polycrystalline thin films were p-type, indirect bandgap semiconductors with absorption coefficient higher than 8 × 104 cm-1. TCO/CdS/AlSb photovoltaic devices with the local open circuit voltage of over 200 mV have been fabricated.

  18. Preparation and Characterization of Blended Films from Quaternized Hemicelluloses and Carboxymethyl Cellulose

    Directory of Open Access Journals (Sweden)

    Xian-Ming Qi

    2015-12-01

    Full Text Available Utilization of hemicelluloses from biomass energy is an important approach to explore renewable resources. A convenient, quick, and inexpensive method for the preparation of blended films from quaternized hemicelluloses (QH and carboxymethyl cellulose (CMC was introduced into this study. QH and CMC solution were first mixed to form homogeneous suspension, and then were dried under vacuum to fabricate the blended films. The FT-IR and XRD results indicated that the linkage between QH and CMC was due to the hydrogen bonding and electrostatic interaction. From the results of mechanical properties and water vapor permeability (WVP, the tensile strength of the blended films increased with the QH/CMC content ratio increasing in appropriate range, and the WVP of the blended films decreased. The maximum value of tensile strength of blend film achieved was 27.4 MPa. In addition, the transmittances of the blended films increased with the decreasing of QH/CMC content ratio. When the weight ratio (QH: CMC was 1:1.5, the blend film showed the best light transmittance (45%. All the results suggested that the blended films could be used in areas of application in the coating and packaging fields from the good tensile strength, transmittance, and low WVP.

  19. Preparation and gas sensing properties of novel CdS-supramolecular organogel hybrid films

    Energy Technology Data Exchange (ETDEWEB)

    Xia Huiyun; Peng Junxia; Liu Kaiqiang; Li Chen; Fang Yu [Key Laboratory of Applied Surface and Colloid Chemistry of Ministry of Education, School of Chemistry and Materials Science, Shaanxi Normal University, Xi' an 710062 (China)], E-mail: yfang@snnu.edu.cn

    2008-05-21

    A novel CdS-supramolecular organogel hybrid film with unusual morphology has been fabricated by exposing a supramolecular organogel film containing Cd(Ac){sub 2} in an H{sub 2}S atmosphere at room temperature. The organogel film was prepared by spin-coating a LMOG (low-molecular weight organic gelator) gel of dmethyl sulfoxide onto a glass plate substrate. XRD, SEM, EDS, TG-DTA, UV-vis, PL (photoluminescence) spectroscopy and PL lifetime measurements were employed to characterize the film. It was shown that the organogel film had functioned as a template to control the morphology of the final hybrid film. The quantities and sizes of the CdS particles embedded in the organogel films can be easily altered by varying the initial concentration of Cd(Ac){sub 2}. Importantly, the PL of the hybrid film is sensitive to the presence of some volatile organic monoamines and diamines. The selectivity and reversibility of the sensing process were investigated.

  20. Influence of preparation methods on photoluminescence properties of ZnO films on quartz glass

    Institute of Scientific and Technical Information of China (English)

    ZHAO Lei; LIAN Jian-she; LIU Yu-hua; JIANG Qing

    2008-01-01

    The influence of preparation methods on the photoluminescence properties of ZnO film was studied. Two methods were applied to fabricate ZnO films in a conventional pulsed laser deposition apparatus. One is high temperature (500-700 ℃) oxidation of the metallic zinc film that is obtained by pulsed laser deposition. The other is pulse laser ablation of Zn target in oxygen atmosphere at low temperature (100-250 ℃). The photoluminescence property was detected by PL spectrum. The room temperature PL spectra of the ZnO films obtained by oxidation method show single violet luminescence emission centered at 424 nm (or 2.90 eV) without any accompanied deep-level emission and UV emission. The violet emission is attributed to interstitial zinc in the films. Nanostructure ZnO film with c-axis (002) orientation is obtained by pulsed laser deposition. The ZnO film deposited at 200 ℃ shows single strong ultraviolet emission. The excellent UV emission is attributed to the good crystalline quality of the film and low intrinsic defects at such low temperature.