Combinatorial thin film materials science: From alloy discovery and optimization to alloy design

International Nuclear Information System (INIS)

Gebhardt, Thomas; Music, Denis; Takahashi, Tetsuya; Schneider, Jochen M.

2012-01-01

This paper provides an overview of modern alloy development, from discovery and optimization towards alloy design, based on combinatorial thin film materials science. The combinatorial approach, combining combinatorial materials synthesis of thin film composition-spreads with high-throughput property characterization has proven to be a powerful tool to delineate composition–structure–property relationships, and hence to efficiently identify composition windows with enhanced properties. Furthermore, and most importantly for alloy design, theoretical models and hypotheses can be critically appraised. Examples for alloy discovery, optimization, and alloy design of functional as well as structural materials are presented. Using Fe-Mn based alloys as an example, we show that the combination of modern electronic-structure calculations with the highly efficient combinatorial thin film composition-spread method constitutes an effective tool for knowledge-based alloy design.

Structural specifics of the condensate prepared by thermal evaporation of alloys of As2S3-Yb systems

International Nuclear Information System (INIS)

Ehfendiev, Eh.G.; Mamedov, A.I.; Il'yasov, T.M.; Rustamov, P.G.

1987-01-01

The problem aimed at preparation of the films of As 2 S 3 -Yb system, at studying their substructure depending on condensation conditions and defining noncrystallinity region of this system in the film state, is formulated. It is shown that in representative samples of As 2 S 3 -Yb system the vitrification region is extended up to 7 at.% Yb, in the films noncrystallinity region is extended up to 30 at.% Yb. With up to 30 at.% increase of ytterbium amount in initial alloys a tendency to crystallization in amorphous condensate structure is noticed. In evaporation of As 2 S 3 + 40 at.% Yb and As 2 S 3 + 50 at.% Yb, unknown in the film state YbAs 2 S 4 , Yb 3 As 4 S 9 and YbAs 4 S 7 phases are prepared, and the latter is formed in case of As 2 S 3 + 50 at.% Yb alloy at small evaporation rates (∼10 A/s). Substructure of As 2 S 3 + 50 at.% Yb alloy prepared condensate is more dependent on evaporation rate than in evaporation of As 2 S 3 + 40 at.% Yb alloy. In this case, evaporation rates being ∼ 100 A/s, the condensate has a polycrystal structure, and at small rates of ∼ 10 A/c, condensate structure is primarily blocked

The Comparison of Biocompatibility Properties between Ti Alloys and Fluorinated Diamond-Like Carbon Films

Directory of Open Access Journals (Sweden)

Chavin Jongwannasiri

2012-01-01

Full Text Available Titanium and titanium alloys have found several applications in the biomedical field due to their unique biocompatibility. However, there are problems associated with these materials in applications in which there is direct contact with blood, for instance, thrombogenesis and protein adsorption. Surface modification is one of the effective methods used to improve the performance of Ti and Ti alloys in these circumstances. In this study, fluorinated diamond-like carbon (F-DLC films are chosen to take into account the biocompatible properties compared with Ti alloys. F-DLC films were prepared on NiTi substrates by a plasma-based ion implantation (PBII technique using acetylene (C2H2 and tetrafluoromethane (CF4 as plasma sources. The structure of the films was characterized by Raman spectroscopy. The contact angle and surface energy were also measured. Protein adsorption was performed by treating the films with bovine serum albumin and fibrinogen. The electrochemical corrosion behavior was investigated in Hanks’ solution by means of a potentiodynamic polarization technique. Cytotoxicity tests were performed using MTT assay and dyed fluorescence. The results indicate that F-DLC films present their hydrophobic surfaces due to a high contact angle and low surface energy. These films can support the higher albumin-to-fibrinogen ratio as compared to Ti alloys. They tend to suppress the platelet adhesion. Furthermore, F-DLC films exhibit better corrosion resistance and less cytotoxicity on their surfaces. It can be concluded that F-DLC films can improve the biocompatibility properties of Ti alloys.

Solar-blind wurtzite MgZnO alloy films stabilized by Be doping

International Nuclear Information System (INIS)

Su, Longxing; Zhu, Yuan; Zhang, Quanlin; Chen, Mingming; Ji, Xu; Wu, Tianzhun; Gui, Xuchun; Xiang, Rong; Tang, Zikang; Pan, Bicai

2013-01-01

Mg x Zn 1−x O alloy films were deposited on c-plane sapphire substrates by radio frequency plasma-assisted molecular beam epitaxy (rf-PMBE). The phase segregation occurred when x was larger than 33%. Be doping was found experimentally able to stabilize the high-Mg-content MgZnO alloy. By alloying 1–2% Be into MgZnO, the band gap of as-prepared quaternary alloys can be raised to the solar-blind range (4.5 eV). Calculated formation energy of the alloys based on first principle reveals that a small amount of Be incorporation can reduce the formation energy of high-Mg-content MgZnO alloys and results in a more stable system, which justifies our experimental observations. (paper)

Insitu grown superhydrophobic Zn–Al layered double hydroxides films on magnesium alloy to improve corrosion properties

Energy Technology Data Exchange (ETDEWEB)

Zhou, Meng; Pang, Xiaolu; Wei, Liang; Gao, Kewei, E-mail: kwgao@yahoo.com

2015-05-15

Highlights: • Hierarchical superhydrophobic Zn–Al LDHs film has been fabricated on a magnesium alloy substrate. • The superhydrophobic surface has good long-term stability under atmospheric environment. • The superhydrophobic surface can provide a stable corrosion protection for the Mg alloys. - Abstract: A hierarchical superhydrophobic zinc–aluminum layered double hydroxides (Zn–Al LDHs) film has been fabricated on a magnesium alloy substrate via a facile hydrothermal crystallization method following chemical modification. The characteristics of the films were investigated by X-ray diffraction (XRD), scanning electronic microscope (SEM), and energy dispersive spectroscopy (EDS). XRD patterns and SEM images showed that the micro/nanoscale hierarchical LDHs film surfaces composed of ZnO nanorods and Zn–Al LDHs nanowalls structures. The static contact angle (CA) for the prepared surfaces was observed at around 165.6°. The corrosion resistance of the superhydrophobic films was estimated by electrochemical impedance spectroscopy (EIS) and potentiondynamic polarization measurement. EIS and polarization measurements revealed that the superhydrophobic Zn–Al LDHs coated magnesium alloy had better corrosion resistance in neutral 3.5 wt.% NaCl solution.

Insitu grown superhydrophobic Zn–Al layered double hydroxides films on magnesium alloy to improve corrosion properties

International Nuclear Information System (INIS)

Zhou, Meng; Pang, Xiaolu; Wei, Liang; Gao, Kewei

2015-01-01

Highlights: • Hierarchical superhydrophobic Zn–Al LDHs film has been fabricated on a magnesium alloy substrate. • The superhydrophobic surface has good long-term stability under atmospheric environment. • The superhydrophobic surface can provide a stable corrosion protection for the Mg alloys. - Abstract: A hierarchical superhydrophobic zinc–aluminum layered double hydroxides (Zn–Al LDHs) film has been fabricated on a magnesium alloy substrate via a facile hydrothermal crystallization method following chemical modification. The characteristics of the films were investigated by X-ray diffraction (XRD), scanning electronic microscope (SEM), and energy dispersive spectroscopy (EDS). XRD patterns and SEM images showed that the micro/nanoscale hierarchical LDHs film surfaces composed of ZnO nanorods and Zn–Al LDHs nanowalls structures. The static contact angle (CA) for the prepared surfaces was observed at around 165.6°. The corrosion resistance of the superhydrophobic films was estimated by electrochemical impedance spectroscopy (EIS) and potentiondynamic polarization measurement. EIS and polarization measurements revealed that the superhydrophobic Zn–Al LDHs coated magnesium alloy had better corrosion resistance in neutral 3.5 wt.% NaCl solution

Large-Grain Tin-Rich Perovskite Films for Efficient Solar Cells via Metal Alloying Technique.

Science.gov (United States)

Tavakoli, Mohammad Mahdi; Zakeeruddin, Shaik Mohammed; Grätzel, Michael; Fan, Zhiyong

2018-03-01

Fast research progress on lead halide perovskite solar cells has been achieved in the past a few years. However, the presence of lead (Pb) in perovskite composition as a toxic element still remains a major issue for large-scale deployment. In this work, a novel and facile technique is presented to fabricate tin (Sn)-rich perovskite film using metal precursors and an alloying technique. Herein, the perovskite films are formed as a result of the reaction between Sn/Pb binary alloy metal precursors and methylammonium iodide (MAI) vapor in a chemical vapor deposition process carried out at 185 °C. It is found that in this approach the Pb/Sn precursors are first converted to (Pb/Sn)I 2 and further reaction with MAI vapor leads to the formation of perovskite films. By using Pb-Sn eutectic alloy, perovskite films with large grain sizes up to 5 µm can be grown directly from liquid phase metal. Consequently, using an alloying technique and this unique growth mechanism, a less-toxic and efficient perovskite solar cell with a power conversion efficiency (PCE) of 14.04% is demonstrated, while pure Sn and Pb perovskite solar cells prepared in this manner yield PCEs of 4.62% and 14.21%, respectively. It is found that this alloying technique can open up a new direction to further explore different alloy systems (binary or ternary alloys) with even lower melting point. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Magnetic properties and crystal texture of Co alloy thin films prepared on double bias Cr

Science.gov (United States)

Deng, Y.; Lambeth, D. N.; Lee, L.-L.; Laughlin, D. E.

1993-05-01

A double layer Cr film structure has been prepared by sputter depositing Cr on single crystal Si substrates first without substrate bias and then with various substrate bias voltages. Without substrate bias, Cr{200} texture grows on Si at room temperature; thus the first Cr layer acts like a seed Cr layer with the {200} texture, and the second Cr layer, prepared with substrate bias, tends to replicate the {200} texture epitaxially. CoCrTa and CoNiCr films prepared on these double Cr underlayers, therefore, tend to have a {112¯0} texture with their c-axes oriented in the plane of the film. At the same time, the bias sputtering of the second Cr layer increases the coercivity of the subsequently deposited magnetic films significantly. Comparison studies of δM curves show that the use of the double Cr underlayers reduces the intergranular exchange interactions. The films prepared on the Si substrates have been compared with the films prepared on canasite and glass substrates. It has also been found that the magnetic properties are similar for films on canasite and on glass.

RF magnetron sputtered TiNiCu shape memory alloy thin film

International Nuclear Information System (INIS)

Fu Yongqing; Du Hejun

2003-01-01

Shape memory alloys (SMAs) offer a unique combination of novel properties, such as shape memory effect, super-elasticity, biocompatibility and high damping capacity, and thin film SMAs have the potential to become a primary actuating mechanism for micro-actuators. In this study, TiNiCu films were successfully prepared by mix sputtering of a Ti 55 Ni 45 target with a separated Cu target. Crystalline structure, residual stress and phase transformation properties of the TiNiCu films were investigated using X-ray diffraction (XRD), differential scanning calorimeter (DSC), and curvature measurement methods. Effects of the processing parameters on the film composition, phase transformation and shape-memory effects were analyzed. Results showed that films prepared at a high Ar gas pressure exhibited a columnar structure, while films deposited at a low Ar gas pressure showed smooth and featureless structure. Chemical composition of TiNiCu thin films was dependent on the DC power of copper target. DSC, XRD and curvature measurement revealed clearly the martensitic transformation of the deposited TiNiCu films. When the free-standing film was heated and cooled, a 'two-way' shape-memory effect can be clearly observed

Preparation of CulnSe2 thin films by paste coating

Institute of Scientific and Technical Information of China (English)

无

2008-01-01

Precursor pastes were obtained by milling Cu-In alloys and Se powders.CuInSe2 thin films were successfully prepared by precursor layers,which were coated using these pastes,and were annealed in a H2 atmosphere.The pastes were tested by laser particle diameter analyzer,simultaneous thermogravimetric and differential thermal analysis instruments (TG-DTA),and X-ray diffractometry (XRD).Selenized films were characterized by XRD,scanning electron microscopy (SEM),and energy dispersive spectroscopy (EDS).The results indicate that chalcopyrite CuInSe2 is formed at 180℃ and the crystallinity of this phase is improved as the temperature rises.All the CuInSe2 thin films,which were annealed at various temperatures,exhibit the preferred orientation along the (112) plane.The compression of precursor layers before selenization step is one oftbe most essential factors for the preparation of perfect CulnSe2 thin films.

A study on electrodeposited NixFe1−x alloy films

Indian Academy of Sciences (India)

Several techniques such as X-ray diffraction [9], VSM. [10], Mössbauer spectroscopy [11], four-point probe [12] etc. are used to investigate the crystallographic, magnetic and magnetotransport properties of NiFe systems. In this study our aim is to prepare NiFe alloy films relatively thicker (in µm scale) than those reported in ...

New barrierless copper-alloy film for future applications

Science.gov (United States)

Lin, Chon-Hsin Lin

2015-09-01

Since Cu metallization results in a conductivity and an electromigration resistance greater than those of Al, it has become popular for making Si-based interconnects for numerous devices in the field of microelectronics. Following the current trend of miniaturization required for most electronic components, there is a greater need for further size reduction in Si-based devices. The most critical side effect of size reduction is the increase in electronic scattering and resistivity when the barrier-layer thickness is further reduced. To explore advanced Cu-metallization methods and to develop a more economical manufacturing process for Cu-alloy films, the development of Cu materials having better quality and higher thermal stability becomes imperative for the metallization and annealing processes. For this purpose, we first fabricated Cu(GeNx) films and examined their thermal stability and electrical reliability after either cyclic or isothermal annealing. The excellent thermal and electrical properties make these new Cu-alloy films highly promising for applications that require more reliable and inexpensive copper interconnects. In this study, we fabricated Cu alloy films by doping a minute amount of Ge or GeNx, respectively, into the Cu films via barrierless Cu metallization, an inexpensive manufacturing method. Using these newly fabricated alloy films, we were able to eliminate or at least substantially reduce the detrimental interaction between the alloy and the barrierless Si substrate. The Cu(GeNx) films also exhibited high thermal stability, low resistivity and leakage current, and long time-dependent dielectric breakdown (TDDB) lifetimes, making such novel films a candidate for high-quality, economical, and more reliable Cu interconnects.

Insitu grown superhydrophobic Zn-Al layered double hydroxides films on magnesium alloy to improve corrosion properties

Science.gov (United States)

Zhou, Meng; Pang, Xiaolu; Wei, Liang; Gao, Kewei

2015-05-01

A hierarchical superhydrophobic zinc-aluminum layered double hydroxides (Zn-Al LDHs) film has been fabricated on a magnesium alloy substrate via a facile hydrothermal crystallization method following chemical modification. The characteristics of the films were investigated by X-ray diffraction (XRD), scanning electronic microscope (SEM), and energy dispersive spectroscopy (EDS). XRD patterns and SEM images showed that the micro/nanoscale hierarchical LDHs film surfaces composed of ZnO nanorods and Zn-Al LDHs nanowalls structures. The static contact angle (CA) for the prepared surfaces was observed at around 165.6°. The corrosion resistance of the superhydrophobic films was estimated by electrochemical impedance spectroscopy (EIS) and potentiondynamic polarization measurement. EIS and polarization measurements revealed that the superhydrophobic Zn-Al LDHs coated magnesium alloy had better corrosion resistance in neutral 3.5 wt.% NaCl solution.

Electronic structures of the L-cysteine film on dental alloys

International Nuclear Information System (INIS)

Ogawa, K.; Tsujibayashi, T.; Takahashi, K.; Azuma, J.; Kakimoto, K.; Kamada, M.

2011-01-01

Research highlights: → The electronic structures of dental alloys and L-cysteine film were studied by PES. → The density of states in the dental alloy originates from Au and Cu as constituents. → The Cu-3d states contribute dominantly to the occupied states near the Fermi level. → The electronic structure of L-cysteine thin film is different from the thick film. → The bonding between Cu-3d and S-3sp states are formed at the interface. - Abstract: Metal-organic interfaces have been attracting continuous attention in many fields including basic biosciences. The surface of dental alloys could be one of such interfaces since they are used in a circumstance full of organic compounds such as proteins and bacteria. In this work, electronic structures of Au-dominant dental alloys, which have Ag and Cu besides Au, and those of L-cysteine on the dental alloys have been studied by photoelectron spectroscopy with synchrotron radiation. It was found that the density of states in the dental alloy originate from gold and copper as constituents, and the Cu-3d states contribute dominantly to the occupied states near the Fermi level. It was also found that the electronic structure of the L-cysteine thin film on the dental alloy is different from that of the L-cysteine thick film. The result indicates the formation of the orbital bonding between Cu-3d and S-3sp states in the thin film on the dental alloy.

Electronic structures of the L-cysteine film on dental alloys

Energy Technology Data Exchange (ETDEWEB)

Ogawa, K., E-mail: e7141@cc.saga-u.ac.jp [Synchrotron Light Application Center, Saga University, Saga 840-8502 (Japan); Tsujibayashi, T. [Department of Physics, Osaka Dental University, Osaka 573-1121 (Japan); Takahashi, K.; Azuma, J. [Synchrotron Light Application Center, Saga University, Saga 840-8502 (Japan); Kakimoto, K. [Department of Geriatric Dentistry, Osaka Dental University, Osaka 573-1121 (Japan); Kamada, M. [Synchrotron Light Application Center, Saga University, Saga 840-8502 (Japan)

2011-04-15

Research highlights: {yields} The electronic structures of dental alloys and L-cysteine film were studied by PES. {yields} The density of states in the dental alloy originates from Au and Cu as constituents. {yields} The Cu-3d states contribute dominantly to the occupied states near the Fermi level. {yields} The electronic structure of L-cysteine thin film is different from the thick film. {yields} The bonding between Cu-3d and S-3sp states are formed at the interface. - Abstract: Metal-organic interfaces have been attracting continuous attention in many fields including basic biosciences. The surface of dental alloys could be one of such interfaces since they are used in a circumstance full of organic compounds such as proteins and bacteria. In this work, electronic structures of Au-dominant dental alloys, which have Ag and Cu besides Au, and those of L-cysteine on the dental alloys have been studied by photoelectron spectroscopy with synchrotron radiation. It was found that the density of states in the dental alloy originate from gold and copper as constituents, and the Cu-3d states contribute dominantly to the occupied states near the Fermi level. It was also found that the electronic structure of the L-cysteine thin film on the dental alloy is different from that of the L-cysteine thick film. The result indicates the formation of the orbital bonding between Cu-3d and S-3sp states in the thin film on the dental alloy.

Study on the poisoning resistance of Pd-coated ZrCo alloy prepared by electroless plating method

Energy Technology Data Exchange (ETDEWEB)

Guo, Xiumei, E-mail: xiumei418@163.com; Wang, Shumao; Li, Zhinian; Yuan, Baolong; Ye, Jianhua; Qiu, Haochen; Wu, Yuanfang; Liu, Xiaopeng; Jiang, Lijun

2016-12-15

Highlights: • The Pd membrane was prepared by electroless plating method. • The Pd membrane was compact and uniform. • The effectiveness of Pd membranes was affected by impurity contents and temperatures. - Abstract: To improve the poisoning resistance of ZrCo alloy, Pd membranes have been prepared over the surface of the alloy substrates by using electroless plating method. The characteristics of Pd membranes have been examined by XRD, SEM, EDS and EPMA technologies. From SEM images, the uniform and compact thin Pd film was revealed. The effect of this Pd film was evaluated by comparing the hydrogen absorption properties of bare and Pd-coated ZrCo specimens in contaminated hydrogen gas. The degradation of hydrogen absorption of Pd-coated ZrCo induced by poisoning was less than that of bare ZrCo sample obviously, meaning that the Pd membranes over the surface of substrates appeared to be effective in improving the poisoning resistance of ZrCo alloy. Furthermore, the effect became more significant with the increasing of impurity contents in the experimental gas and the operation temperatures.

Perpendicular Magnetic Anisotropy in Heusler Alloy Films and Their Magnetoresistive Junctions

Directory of Open Access Journals (Sweden)

Atsufumi Hirohata

2018-01-01

Full Text Available For the sustainable development of spintronic devices, a half-metallic ferromagnetic film needs to be developed as a spin source with exhibiting 100% spin polarisation at its Fermi level at room temperature. One of the most promising candidates for such a film is a Heusler-alloy film, which has already been proven to achieve the half-metallicity in the bulk region of the film. The Heusler alloys have predominantly cubic crystalline structures with small magnetocrystalline anisotropy. In order to use these alloys in perpendicularly magnetised devices, which are advantageous over in-plane devices due to their scalability, lattice distortion is required by introducing atomic substitution and interfacial lattice mismatch. In this review, recent development in perpendicularly-magnetised Heusler-alloy films is overviewed and their magnetoresistive junctions are discussed. Especially, focus is given to binary Heusler alloys by replacing the second element in the ternary Heusler alloys with the third one, e.g., MnGa and MnGe, and to interfacially-induced anisotropy by attaching oxides and metals with different lattice constants to the Heusler alloys. These alloys can improve the performance of spintronic devices with higher recording capacity.

Alloying behaviour of electroplated Ag film with its underlying Pd/Ti film stack for low resistivity interconnect metallization

International Nuclear Information System (INIS)

Ezawa, Hirokazu; Miyata, Masahiro; Tatsumi, Kohei

2014-01-01

Highlights: • Alloying behavior of Ag/Pd/Ti film stack was studied by annealing at 400-800 °C. • The Ag film resistivity decreased with increasing annealing temperature. • Formation of the Pd-Ti intermetallics was found to be dominant over Ag-Pd alloying. • The excess Ti was consumed to form Ti oxides, which inhibited Ti alloying with Ag. -- Abstract: In this paper, viability of electroplated Ag film into device application was studied. Alloying behavior of the Ag film with its underlying Pd(50 nm)/Ti(100 nm) film stack was investigated with respect to heat treatment at different temperatures from 400 °C to 800 °C in an argon ambient. After annealing at 400 °C, the electrical resistivity of the Ag film increased due to Pd alloying with Ag. Formation of Pd–Ti intermetallic phases became dominant over Ag–Pd alloying with increasing annealing temperature, leading to the resistivity decrease of the Ag film. The resistivity of the 800 °C annealed Ag film approached that of its as-plated Ag film. The excess Ti atoms which were not consumed to form the intermetallic phases with the Pd atoms migrated to the Ag film surface to form Ti oxides along the Ag grain boundaries on the topmost film surface. The Ag/Pd/Ti film stack has been confirmed to maintain the resistivity of the Ag film at as-plated low levels after high temperature annealing. This paper also discusses process integration issues to enable the Ag metallization process for future scaled and three dimensionally chip stacked devices

Characteristics of Iron-Palladium alloy thin films deposited by magnetron sputtering

Science.gov (United States)

Chiu, Y.-J.; Shen, C.-Y.; Chang, H.-W.; Jian, S.-R.

2018-06-01

The microstructural features, magnetic, nanomechanical properties and wettability behaviors of Iron-Palladium (FePd) alloy thin films are investigated by using X-ray diffraction (XRD), atomic force microscopy (AFM), vibrating sample magnetometer (VSM), nanoindentation and water contact angle (CA) techniques, respectively. The FePd alloy thin films were deposited on glass substrates using a magnetron sputtering system. The post-annealing processes of FePd alloy thin films were carried out at 400 °C and 750 °C and resulted in a significant increase of both the average grain size and surface roughness. The XRD analysis showed that FePd alloy thin films exhibited a predominant (1 1 1) orientation. The magnetic field dependence of magnetization of all FePd thin films are measured at room temperature showed the ferromagnetic characteristics. The nanoindentation with continuous stiffness measurement (CSM) is used to measure the hardness and Young's modulus of present films. The contact angle (θCA) increased with increasing surface roughness. The maximum θCA of 75° was achieved for the FePd alloy thin film after annealing at 750 °C and a surface roughness of 4.2 nm.

PREPARATION OF ACTINIDE-ALUMINUM ALLOYS

Science.gov (United States)

Moore, R.H.

1962-09-01

BS>A process is given for preparing alloys of aluminum with plutonium, uranium, and/or thorium by chlorinating actinide oxide dissolved in molten alkali metal chloride with hydrochloric acid, chlorine, and/or phosgene, adding aluminum metal, and passing air and/or water vapor through the mass. Actinide metal is formed and alloyed with the aluminum. After cooling to solidification, the alloy is separated from the salt. (AEC)

Study of Fe-Ni-Si-B alloy and films on its base by X-ray photospectroscopy method

International Nuclear Information System (INIS)

Kozlenko, V.G.; Parfenenok, M.A.; Pukhov, I.K.; Shaposhnikov, A.N.; Shirkov, A.V.

1983-01-01

By the method of X ray photoelectron spectroscopy the chemical composition of Fe-Ni-Si-B alloy and films on its base prepared by ion-plasma sputtering is investigated. The identity of chemical bonds in film samples and initial target is revealed, realized are in them mostly Fe-B, Ni-C, Si-Si interatomic bonds. It is shown that lono. films contact with atmosphere is the cause of difference of film composition in the near-surface region (up to 100 nm) from its main volume composition

Oxide films on magnesium and magnesium alloys

International Nuclear Information System (INIS)

Shih, T.-S.; Liu, J.-B.; Wei, P.-S.

2007-01-01

Magnesium alloys are very active and readily ignite during heating and melting. In this study, we discuss the combustion of magnesium and magnesium alloys and propose prospective anti-ignition mechanisms for magnesium alloys during the heating process. When magnesium and magnesium alloys were heated in air, the sample surfaces produced layers of thermally formed oxides. These thermally formed oxides played an important role in affecting the combustion of the magnesium and magnesium alloys. When magnesium was heated in air, brucite that formed in the early stage was then transformed into periclase by dehydroxylation. By extending the heating time, more periclase formed and increased in thickness which was associated with microcracks formation. When magnesium was heated in a protective atmosphere (SF 6 ), a film of MgF 2 formed at the interface between the oxide layer and the Mg substrate. This film generated an anti-ignition behavior which protected the substrate from oxidation. When solution-treated AZ80 alloy was heated, spinel developed at the interface between the thermally formed oxide layer and the Mg substrate, improving the anti-ignition properties of the substrate. In addition, we also explain the effects of beryllium in an AZB91 alloy on the ignition-proofing behavior

Corrosion properties of the Mg alloy coated with polypyrrole films

International Nuclear Information System (INIS)

Grubač, Zoran; Rončević, Ivana Škugor; Metikoš-Huković, Mirjana

2016-01-01

Highlights: • Electropolymerization of pyrrole on Mg-alloy surface in presence of salicylate. • Salicylate dual role in PPy deposition: passivation and electron transfer mediation. • Redox potential of salicylate corresponds to potential of PPy nucleation. • EIS and polarization corrosion studies of PPy coated Mg-alloy in Hanks’ solution. • Polypyrrole significantly slowdown Mg alloy corrosion in Hanks’ solution. - Abstract: In the present study the reactive surface of Mg alloy was coated with the nontoxic biocompatible polypyrrole (PPy) film synthesized by electrochemical oxidation from an aqueous salicylate solution. Salicylate ions prevent Mg dissolution and act as an electron transfer mediator during the PPy film nucleation, formation and growth on the alloy surface. Kinetics of the pyrrole polymerization as well as corrosion resistance of the PPy coated Mg alloy in the Hanks’ solution were investigated using dc electrochemical methods and electrochemical impedance spectroscopy (EIS). Characterization of the surface film was performed by optical and Fourier transform infrared spectroscopy (FTIR).

Dissociation of dilute immiscible copper alloy thin films

International Nuclear Information System (INIS)

Barmak, K.; Lucadamo, G. A.; Cabral, C. Jr.; Lavoie, C.; Harper, J. M. E.

2000-01-01

The dissociation behavior of dilute, immiscible Cu-alloy thin films is found to fall into three broad categories that correlate most closely with the form of the Cu-rich end of the binary alloy phase diagrams. Available thermodynamic and tracer diffusion data shed further light on alloy behavior. Eight alloying elements were selected for these studies, with five elements from groups 5 and 6, two from group 8, and one from group 11 of the periodic table. They are respectively V, Nb, Ta, Cr, Mo, Fe, Ru, and Ag. The progress of precipitation in approximately 500-nm-thick alloy films, containing 2.5-3.8 at. % solute, was followed with in situ resistance and stress measurements as well as with in situ synchrotron x-ray diffraction. In addition, texture analysis and transmission electron microscopy were used to investigate the evolution of microstructure and texture of Cu(Ta) and Cu(Ag). For all eight alloys, dissociation occurred upon heating, with the rejection of solute and evolution of microstructure often occurring in multiple steps that range over several hundred degrees between approximately 100 and 900 degree sign C. However, in most cases, substantial reductions in resistivity of the films took place below 400 degree sign C, at temperatures of interest to copper metallization schemes for silicon chip technology. (c) 2000 American Institute of Physics

The Effect of Modulation Ratio of Cu/Ni Multilayer Films on the Fretting Damage Behaviour of Ti-811 Titanium Alloy.

Science.gov (United States)

Zhang, Xiaohua; Liu, Daoxin; Li, Xiaoying; Dong, Hanshan; Xi, Yuntao

2017-05-26

To improve the fretting damage (fretting wear and fretting fatigue) resistance of Ti-811 titanium alloy, three Cu/Ni multilayer films with the same modulation period thickness (200 nm) and different modulation ratios (3:1, 1:1, 1:3) were deposited on the surface of the alloy via ion-assisted magnetron sputtering deposition (IAD). The bonding strength, micro-hardness, and toughness of the films were evaluated, and the effect of the modulation ratio on the room-temperature fretting wear (FW) and fretting fatigue (FF) resistance of the alloy was determined. The results indicated that the IAD technique can be successfully used to prepare Cu/Ni multilayer films, with high bonding strength, low-friction, and good toughness, which yield improved room-temperature FF and FW resistance of the alloy. For the same modulation period (200 nm), the micro-hardness, friction, and FW resistance of the coated alloy increased, decreased, and improved, respectively, with increasing modulation ratio of the Ni-to-Cu layer thickness. However, the FF resistance of the coated alloy increased non-monotonically with the increasing modulation ratio. Among the three Cu/Ni multilayer films, those with a modulation ratio of 1:1 can confer the highest FF resistance to the Ti-811 alloy, owing mainly to their unique combination of good toughness, high strength, and low-friction.

Preparation of Trivalent Chromium and Rare Earth Composite Conversion Coating on Aluminum Alloy Surface

Science.gov (United States)

Huang, Jianzhen

2018-01-01

In this paper, the surface conversion film on 6063 aluminum alloy was prepared by chemical plating process with chromium sulfate, lanthanum sulfate and sodium phosphate as film forming agent. The corrosion resistance and surface morphology of the conversion film were analyzed by pitting corrosion test of copper sulfate and SEM. The results show that when Cr2(SO4)3 is 10 g/L, La2(SO4)3 is 2 g/L, Na3PO4 is 8 g/L, pH value is 3, temperature is 40 °C, reaction time is 10 min, the corrosion resistance of the surface conversion film is the best. The conversion coating is light green, composed of Cr, La, P, Al, O and other elements.

Electrodeposition of Cu-In alloys for preparing CuInS sub 2 thin films

Energy Technology Data Exchange (ETDEWEB)

Herrero, J; Ortega, J [Inst. de Energias Renovables (CIEMAT), Madrid (Spain)

1990-01-01

Copper-indium alloys were prepared by electroplating from citric acid (C{sub 6}H{sub 8}O{sub 7}.H{sub 2}O) baths onto Ti substrate. Formation of the alloys was carried out by direct codeposition of the elements and by sequential electrodeposition of copper and indium. Studies of the alloy formation by electrochemical measurements and X-ray diffraction were performed. The presence of Cu{sub 7}In{sub 4} in direct deposit as well as in sequentially electrodeposited material was observed during the alloy formation. The as-deposited layers were heated in H{sub 2}S. X-ray diffraction showed the annealed layers to be CuInS{sub 2} with the chalcopyrite structure, where the CuIn{sub 5}S{sub 8} phase was included during the annealing process. Photoelectrochemical characterization of the samples allowed us to determine the photoconductivity which is related with the Cu/In ratio in the samples. The energy gap for CuInS{sub 2} photoelectrodes in polysulphide solution was 1.57 Ev. (orig.).

Thermal Stability of Copper-Aluminum Alloy Thin Films for Barrierless Copper Metallization on Silicon Substrate

Science.gov (United States)

Wang, C. P.; Dai, T.; Lu, Y.; Shi, Z.; Ruan, J. J.; Guo, Y. H.; Liu, X. J.

2017-08-01

Copper thin films with thickness of about 500 nm doped with different aluminum concentrations have been prepared by magnetron sputtering on Si substrate and their crystal structure, microstructure, and electrical resistivity after annealing at various temperatures (200°C to 600°C) for 1 h or at 400°C for different durations (1 h to 11 h) investigated by grazing-incidence x-ray diffraction (GIXRD) analysis, scanning electron microscopy (SEM), and four-point probe (FPP) measurements. Cu-1.8Al alloy thin film exhibited good thermal stability and low electrical resistivity (˜5.0 μΩ cm) after annealing at 500°C for 1 h or 400°C for 7 h. No copper silicide was observed at the Cu-Al/Si interface by GIXRD analysis or SEM for this sample. This result indicates that doping Cu thin film with small amounts of Al can achieve high thermal stability and low electrical resistivity, suggesting that Cu-1.8Al alloy thin film could be used for barrierless Cu metallization on Si substrate.

Polycrystalline Mn-alloyed indium tin oxide films

International Nuclear Information System (INIS)

Scarlat, Camelia; Schmidt, Heidemarie; Xu, Qingyu; Vinnichenko, Mykola; Kolitsch, Andreas; Helm, Manfred; Iacomi, Felicia

2008-01-01

Magnetic ITO films are interesting for integrating ITO into magneto-optoelectronic devices. We investigated n-conducting indium tin oxide (ITO) films with different Mn doping concentration which have been grown by chemical vapour deposition using targets with the atomic ratio In:Sn:Mn=122:12:0,114:12:7, and 109:12:13. The average film roughness ranges between 30 and 50 nm and XRD patterns revealed a polycrystalline structure. Magnetotransport measurements revealed negative magnetoresistance for all the samples, but high field positive MR can be clearly observed at 5 K with increasing Mn doping concentration. Spectroscopic ellipsometry (SE) has been used to prove the existence of midgap states in the Mn-alloyed ITO films revealing a transmittance less than 80%. A reasonable model for the ca. 250 nm thick Mn-alloyed ITO films has been developed to extract optical constants from SE data below 3 eV. Depending on the Mn content, a Lorentz oscillator placed between 1 and 2 eV was used to model optical absorption below the band gap

Chemical state and phase structure of (TaNbTiW)N films prepared by combined magnetron sputtering and PBII

Energy Technology Data Exchange (ETDEWEB)

Feng, Xingguo [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Tang, Guangze [National Key Laboratory of Materials Behavior and Evaluation in Space Environment, Harbin Institute of Technology, Harbin 150001 (China); Sun, Mingren [National Key Laboratory of Science and Technology on Precision Hot Processing of Metals Harbin Institute of Technology, Harbin Institute of Technology, Harbin 150001 (China); Ma, Xinxin, E-mail: maxin@hit.edu.cn [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Wang, Liqin [School of Mechatronics Engineering, Harbin Institute of Technology, Harbin, 150001 (China)

2013-09-01

(TaNbTiW)N films with thickness of ∼1000 nm are prepared on titanium alloy substrate by combined magnetron sputtering deposition and nitrogen plasma based ion implantation (N-PBII). Chemical state of the elements and phase structure of the films are investigated using X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD), respectively. The bonds of Ta-N, Nb-N, Ti-N-O and Ta-O are detected in the (TaNbTiW)N films, however both W-N and W-O are not found. The initial alloy film has a BCC structure, while the films with N-PBII treatment are composed of BCC and FCC structures. The hardness and elastic modulus of the films can be improved by increasing nitrogen implantation dose and reach maximum values of 9.0 GPa and 154.1 GPa, respectively.

Effects of glycine and current density on the mechanism of electrodeposition, composition and properties of Ni-Mn films prepared in ionic liquid

Science.gov (United States)

Guo, Jiacheng; Guo, Xingwu; Wang, Shaohua; Zhang, Zhicheng; Dong, Jie; Peng, Liming; Ding, Wenjiang

2016-03-01

The effects of glycine on the mechanism of electrodeposition of Ni-Mn alloy film prepared in ChCl-urea ionic liquid were studied in order to control the composition, microstructure and properties of the film. The cyclic voltammograms revealed that the presence of glycine in the ionic liquid can inhibit the reduction of Ni2+ ions but promote the reduction of Mn2+ ions in the cathodic scan. However, it promoted the dissolution of both Ni and Mn deposits in the ChCl-urea ionic liquids during the reverse scan. Glycine changed the mode of Ni-Mn film growth from Volmer-Weber mode into Stranski-Krastanov mode. The Mn content in the Ni-Mn film increased with the increase of concentration of glycine and current density. The Ni-Mn alloy film with 3.1 at.% Mn exhibited the lowest corrosion current density of 3 × 10-7 A/cm2 compared with other films prepared and exhibited better corrosion resistance than pure Ni film in 3.5 wt.% NaCl solution.

Investigation of the HA film deposited on the porous Ti6Al4V alloy prepared via additive manufacturing

International Nuclear Information System (INIS)

Surmeneva, M; Chudinova, E; Syrtanov, M; Surmenev, R; Koptioug, A

2015-01-01

This study is focused on the use of radio frequency magnetron sputtering to modify the surface of porous Ti6Al4V alloy fabricated via additive manufacturing technology. The hydroxyapatite (HA) coated porous Ti6Al4V alloy was studied in respect with its chemical and phase composition, surface morphology, water contact angle and hysteresis, and surface free energy. Thin nanocrystalline HA film was deposited while its structure with diamond-shaped cells remained unchanged. Hysteresis and water contact angle measurements revealed an effect of the deposited HA films, namely an increased water contact angle and contact angle hysteresis. The increase of the contact angle of the coating-substrate system compared to the uncoated substrate was attributed to the multiscale structure of the resulted surfaces. (paper)

Effects of benzotriazole on anodized film formed on AZ31B magnesium alloy in environmental-friendly electrolyte

International Nuclear Information System (INIS)

Guo Xinghua; An Maozhong; Yang Peixia; Li Haixian; Su Caina

2009-01-01

An environmental-friendly electrolyte of silicate and borate, which contained an addition agent of 1H-benzotriazole (BTA) with low toxicity (LD50 of 965 mg/kg), was used to prepare an anodized film on AZ31B magnesium alloy under the constant current density of 1.5 A/dm 2 at room temperature. Effects of BTA on the properties of the anodized film were studied by scanning electron microscopy (SEM), energy dispersion spectrometry (EDS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), loss weight measurement, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS), respectively. The results demonstrated that anodized growth process, surface morphology, thickness, phase structure and corrosion resistance of the anodized film were strongly dependant on the BTA concentration, which might be attributed to the formation of an BTA adsorption layer on magnesium substrate surface. When the BTA concentration was 5 g/L in the electrolyte, a compact and thick anodized film could provide excellent corrosion resistance for AZ31B magnesium alloy.

[Corrosion property and oxide film of dental casting alloys before and after porcelain firing].

Science.gov (United States)

Ma, Qian; Wu, Feng-ming

2011-03-01

To evaluate the types and compositions of oxide films formed during porcelain-fused-to-metal (PFM) firing on three kinds of dental casting alloys, and to investigate the corrosion property of these alloys in Dulbecco's modification of Eagle's medium (DMEM) cell culture fluid, before and after PFM firing. Specimens of three dental casting alloys (Ni-Cr, Co-Cr and Ni-Ti) before and after PFM firing were prepared, and were immersed in DMEM cell culture fluid. After 30 days, the type and concentration of released metal ions were measured using inductively coupled plasma atomic emission spectroscopy (ICP-AES). X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM) were used for analysis of oxide film on the alloys. One way-ANOVA was adopted in data analysis. The total amount of metal ions released from the three dental alloys was found to be highest in Ni-Cr alloy [(2.829 ± 0.694) mg/L], followed by Co-Cr [(2.120 ± 0.418) mg/L] and Ni-Ti alloy [(1.211 ± 0.101) mg/L]. The amount of Ni ions released from Ni-Cr alloys [(1.531 ± 0.392) mg/L] was higher than that from Ni-Ti alloys [(0.830 ± 0.052) mg/L]. The amount of Cr, Mo ions released from Co-Cr alloy [Cr: (0.048 ± 0.011) mg/L, Mo: (1.562 ± 0.333) mg/L] was higher than that from Ni-Cr alloy [Cr: (0.034 ± 0.002) mg/L, Mo: (1.264 ± 0.302) mg/L] and Ni-Ti alloy [Cr: (0.013 ± 0.006) mg/L, Mo: (0.151 ± 0.026) mg/L] (P < 0.05). After PFM firing, the total amount of metal irons released from the three dental alloys decreased [Ni-Cr: (0.861 ± 0.054) mg/L, Co-Cr: (0.695 ± 0.327) mg/L, Ni-Ti: (0.892 ± 0.115) mg/L] (P < 0.05). In addition, XPS showed increase of Cr(2)O(3) and Mo-Ni oxide on the surface of all the alloys after PFM firing. The amount of ions released from Ni-Cr alloy was the highest among the three dental casting alloys, this means Ni-Cr alloy is prone to corrode. The PFM firing process changed the alloys' surface composition. Increased Ni, Cr and Mo were found in oxide film, and

A Study on Sealing Process of Anodized Al Alloy Film

Science.gov (United States)

Tsujita, Takeshi; Sato, Hiroshi; Tsukahara, Sonoko; Ishikawa, Yuuichi

Since sealing is an important process to improve the corrosion resistance in practical application of anodized aluminum, we prepared anodic oxide films on A5052 alloy in an oxalic acid bath and a sulfuric acid bath, sealed them at various conditions, and analyzed them by scanning electron microscopy, acid-dissolution examination, admittance measurements and infrared spectroscopy. The pore radius of the oxalic acid anodized film was about 5 times larger than that of sulfuric acid anodized film, while the corrosion resistance of the former showed about 2 times higher value than the latter with the same sealed state and amount of hydroxide formed by sealing process of the former was 6 times larger than the latter, respectively. Steam sealing formed dense hydroxide and boiling water sealing formed big coral-like hydroxide, whereas the corrosion resistance of the film sealed by the former showed about 1.5 times higher value than that sealed by the latter, respectively. Thus microstructure of anodic oxide films and their surface morphology after sealing process clearly depended on their anodizing solution and the sealing condition and showed obvious relation to electric and corrosive properties.

Synthesis and characterization of Cu–Al–Ni shape memory alloy multilayer thin films

International Nuclear Information System (INIS)

Gómez-Cortés, J.F.; San Juan, J.; López, G.A.; Nó, M.L.

2013-01-01

Among active materials, shape memory alloys are well recognized for their work output density. Because of that, these alloys have attracted much attention to be used in micro/nano electromechanical systems. In the present work, the electron beam evaporation technique has been used to growth, by a multilayer method, two shape memory alloy thin films with different Cu–Al–Ni composition. Multilayers have been further thermally treated to produce the alloys by solid solution diffusion. The produced multilayers have been characterized and the presence of the martensite phase in the obtained thin films was studied. Furthermore, the influence of two different coatings onto the Si substrates, namely Si/SiO 2 and Si/Si 3 N 4 , was investigated. Mechanically stable, not detaching from the substrates, Cu–Al–Ni shape memory alloy thin films, about 1 micrometre thick, showing a martensitic transformation have been produced. - Highlights: ► Multilayer thin films of Cu–Al–Ni shape memory alloys produced by e-beam evaporation. ► SiN X 200 nm thick coating is good for high quality Cu–Al–Ni shape memory thin films. ► Thermal treatment renders Cu–Al–Ni multilayer in homogeneous martensite thin film

Alloying process of sputter-deposited Ti/Ni multilayer thin films

International Nuclear Information System (INIS)

Cho, H.; Kim, H.Y.; Miyazaki, S.

2006-01-01

Alloying process of a Ti/Ni multilayer thin film was investigated in detail by differential scanning calorimetry (DSC), X-ray diffractometry (XRD) and transmission electron microscopy (TEM). The Ti/Ni multilayer thin film was prepared by depositing Ti and Ni layers alternately on a SiO 2 /Si substrate. The number of each metal layer was 100, and the total thickness was 3 μm. The alloy composition was determined as Ti-51 at.%Ni by electron probe micro analysis (EPMA). The DSC curve exhibited three exothermic peaks at 621, 680 and 701 K during heating the as-sputtered multilayer thin film. In order to investigate the alloying process, XRD and TEM observation was carried out for the specimens heated up to various temperatures with the heating rate same as the DSC measurement. The XRD profile of the as-sputtered film revealed only diffraction peaks of Ti and Ni. But reaction layers of 3 nm in thickness were observed at the interfaces of Ti and Ni layers in cross-sectional TEM images. The reaction layer was confirmed as an amorphous phase by the nano beam diffraction analysis. The XRD profiles exhibited that the intensity of Ti diffraction peak decreased in the specimen heat-treated above 600 K. The peak from Ni became broad and shifted to lower diffraction angle. The amorphous layer thickened up to 6 nm in the specimen heated up to 640 K. The diffraction peak corresponding to Ti-Ni B2 phase appeared and the peak from Ni disappeared for the specimen heated up to 675 K. The Ti-Ni B2 crystallized from the amorphous reaction layer. After further heating above the third exothermic peak, the intensity of the peak from the Ti-Ni B2 phase increased, the peak from Ti disappeared and the peaks corresponding to Ti 2 Ni appeared. The Ti 2 Ni phase was formed by the reaction of the Ti-Ni B2 and Ti

The preparation and corrosion behaviors of MAO coating on AZ91D with rare earth conversion precursor film

Energy Technology Data Exchange (ETDEWEB)

Cai Jingshun [Department of Chemistry, Zhejiang University, Zheda Road 38, Hangzhou, Zhejiang 310027 (China); Cao Fahe, E-mail: nelson_cao@zju.edu.cn [Department of Chemistry, Zhejiang University, Zheda Road 38, Hangzhou, Zhejiang 310027 (China); Chang Linrong; Zheng Junjun [Department of Chemistry, Zhejiang University, Zheda Road 38, Hangzhou, Zhejiang 310027 (China); Zhang Jianqing; Cao Chunan [Department of Chemistry, Zhejiang University, Zheda Road 38, Hangzhou, Zhejiang 310027 (China); State Key Laboratory for Corrosion and Protection, Institute of Metal Research, The Chinese Academy of Sciences, Shenyang 110016 (China)

2011-02-01

A novel kind of micro-arc oxidation (MAO) coating was prepared on magnesium alloy surface coated with rare earth conversion film (RE-film) in an alkaline aluminum oxidation electrolyte by AC power source. Inspection of scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) microspectroscopy, the structure and composition of MAO coating formed on AZ91D with RE-film under different applied voltages were investigated and the performance of the optimized MAO coating compared with the MAO coating directly formed on magnesium alloy. As the pretreatment of magnesium alloy with RE-film, the cerium oxides can be incorporated into the MAO coatings, reduce porosity of the MAO coating surface and enhance the thickness of MAO coating. These structure features and the cerium oxides incorporated into the MAO coating result in greatly improved corrosion resistance. Base on electrochemistry impedance spectroscopy (EIS) measurement, the electronic structure and composition analysis of the MAO coating, a double-layer structure, with a compact inner layer and a porous outer layer, of the coating was proposed for understanding its corrosion process.

The preparation and corrosion behaviors of MAO coating on AZ91D with rare earth conversion precursor film

International Nuclear Information System (INIS)

Cai Jingshun; Cao Fahe; Chang Linrong; Zheng Junjun; Zhang Jianqing; Cao Chunan

2011-01-01

A novel kind of micro-arc oxidation (MAO) coating was prepared on magnesium alloy surface coated with rare earth conversion film (RE-film) in an alkaline aluminum oxidation electrolyte by AC power source. Inspection of scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) microspectroscopy, the structure and composition of MAO coating formed on AZ91D with RE-film under different applied voltages were investigated and the performance of the optimized MAO coating compared with the MAO coating directly formed on magnesium alloy. As the pretreatment of magnesium alloy with RE-film, the cerium oxides can be incorporated into the MAO coatings, reduce porosity of the MAO coating surface and enhance the thickness of MAO coating. These structure features and the cerium oxides incorporated into the MAO coating result in greatly improved corrosion resistance. Base on electrochemistry impedance spectroscopy (EIS) measurement, the electronic structure and composition analysis of the MAO coating, a double-layer structure, with a compact inner layer and a porous outer layer, of the coating was proposed for understanding its corrosion process.

Formation of Ag nanoparticles in percolative Ag–PbTiO3 composite thin films through lead-rich Ag–Pb alloy particles formed as transitional phase

International Nuclear Information System (INIS)

Hu, Tao; Wang, Zongrong; Su, Yanbo; Tang, Liwen; Shen, Ge; Song, Chenlu; Han, Gaorong; Weng, Wenjian; Ma, Ning; Du, Piyi

2012-01-01

The Ag nanoparticle dispersed percolative PbTiO 3 ceramic thin film was prepared in situ by sol–gel method with excess lead introduced into a sol precursor. The influence of excess lead and the heat treatment time on the formation of Ag nanoparticles was investigated by energy dispersive X-ray spectra, scanning electron microscopy, X-ray diffraction, and ultraviolet–visible absorption spectra. Results showed that the excess lead introduced into the sol precursor was in favor of the crystallization of the thin film and in favor of formation of the perovskite phase without the pyrochlore phase. Lead-rich Ag–Pb alloy particles first formed in the thin films and then decomposed to become large numbers of Ag nanoparticles of about 3 nm in size in the thin films when the heat treatment time was longer than 2 min. The content of the Ag nanoparticles increased with increasing the heat treatment time. The percolative behavior appears typically in the Ag nanoparticle dispersed thin films. The dielectric constant of the thin film was about 3 times of that without Ag nanoparticles. - Highlights: ► The Ag nanoparticles formed in the PbTiO 3 percolative ceramic thin film. ► The Ag–Pb alloy particles formed as transitional phase during thin film preparation. ► The lead-rich Ag–Pb alloy particles decomposed to form Ag nanoparticles in the film. ► Permittivity of the thin film is 3 times higher than that without Ag nanoparticles.

Formation of SmFe5(0001) ordered alloy thin films on Cu(111) single-crystal underlayers

International Nuclear Information System (INIS)

Yabuhara, Osamu; Ohtake, Mitsuru; Nukaga, Yuri; Futamoto, Masaaki; Kirino, Fumiyoshi

2010-01-01

SmFe 5 (0001) single-crystal thin films are prepared by molecular beam epitaxy employing Cu(111) single-crystal underlayers on MgO(111) substrates. The Cu atoms diffuse into the Sm-Fe layer and substitute the Fe sites in SmFe 5 structure forming an alloy compound of Sm(Fe,Cu) 5 . The Sm(Fe,Cu) 5 film is more Cu enriched with increasing the substrate temperature. The Cu underlayer plays an important role in assisting the formation of the ordered phase.

Controlling the alloy composition of PtNi nanocrystals using solid-state dewetting of bilayer films

Energy Technology Data Exchange (ETDEWEB)

Seo, Okkyun; Oh, Se An; Lee, Ji Yeon; Ha, Sung Soo; Kim, Jae Myung; Choi, Jung Won; Kim, Jin-Woo [Department of Physics and Photon Science & School of Materials Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 61005 (Korea, Republic of); Kang, Hyon Chol [Department of Materials and Science Engineering, Chosun University, Gwangju 61542 (Korea, Republic of); Noh, Do Young, E-mail: dynoh@gist.ac.kr [Department of Physics and Photon Science & School of Materials Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 61005 (Korea, Republic of)

2016-05-15

We demonstrate that solid-state dewetting of bilayer films is an effective way for obtaining bimetallic alloy nanocrystals of controlled composition. When a Pt–Ni bilayer film were annealed near 700 °C, Pt and Ni atoms inter-diffused to form a PtNi bimetallic alloy film. Upon annealing at higher temperatures, the bilayer films transformed into <111> oriented PtNi alloy nanocrystals in small-rhombicuboctahedron shape through solid-state dewetting process. The Pt content of the nanocrystals and the alloy films, estimated by applying the Vegard's law to the relaxed lattice constant, was closely related to the thickness of each layer in the as-grown bilayer films which can be readily controlled during bilayer deposition. - Highlights: • Composition control of PtNi nanoparticles using solid state dewetting is proposed. • PtNi alloy composition was controlled by thickness ratio of Pt–Ni bilayer films. • PtNi alloy nanocrystals were obtained in small-rhombicuboctahedron shape.

Characteristics of Film Formed on Alloy 600 and Alloy 690 in Water Containing lead

International Nuclear Information System (INIS)

Hwang Seong Sik; Lee, Deok Hyun; Kim, Hong Pyo; Kim, Joung Soo; Kim, Ju Yup

1999-01-01

Anodic polarization behaviors of Alloy 600 and Alloy 690 have been studied as a function of lead content in the solution of pH 4 and 10 at 90 .deg. C. As the amount of lead in the solution increased, critical current densities and passive current densities of Alloy 600 and Alloy 690 increased, while the breakdown potential of the alloys decreased. The high critical current density in the high lead solution was thought to come from the combination of an enhanced dissolution of constituents on the surface of the alloys by the lead and an anodic dissolution of metallic lead deposited on the surface of the specimens. The morphology of lead precipitated on the specimen after the anodic scan changed with the pH of solution: small irregular particles were precipitated on the surface of the specimen in the solution of pH 4, while the high density of regular sized particles was formed on it in the solution of pH 10.Pb was observed to enhance Cr depletion from the outer surface of Alloy 600 and Alloy 690 and also to increase the ratio of O 2- /OH - in the surface film formed in the high lead solution. The SCC resistance of Alloy 600 and Alloy 690 may have decreased due to the poor quality of the passive film formed and the enhanced oxygen evolution in the solution containing lead

Magnetooptical garnet films: preparation, characterisation, application

International Nuclear Information System (INIS)

Goernert, P.; Lorenz, A.; Lindner, M.; Richert, H.

2007-01-01

Full text: In contemporary magnetooptics both Kerr effect and Faraday effect are applied. The Kerr effect of metals and alloys - such as Fe, Ni, Co, FePt, CoPt, MnBi, PtMnSb - with thicknesses 300 μm are established as commercial isolators in optical systems and for developments of waveguide applications. Bi-REIG is prepared mostly by conventional liquid phase epitaxy (LPE) in PbO-B 2 O 3 -Bi 2 O 3 based solvents and sometimes by laser ablation and as nanocrystalline powders. In each case high Faraday rotation and low optical absorption is necessary. Additionally, magnetooptical sensors should possess high sensitivity and a large dynamic range. All these demands can be fulfilled with (REBi) 3 (FeGaAl) 5 O 12 LPE layers. Here we discuss some new results concerning preparation, characterisation, and application of Bi-TmIG and Bi-DyIG LPE layers on high-quality gadolinium gallium garnet (GGG) or lattice matched Ca-, Mg-, Zr-substituted GGG substrates. Optimization of flux melt composition and under cooling result in sensor films with a Faraday rotation of e.g. -1.2 0 /μm at a wavelength of l=590 nm and saturation induction of Bs=70 mT. Such films are already applied for forensic investigations. However, the responsivity of the garnet films is restricted by their coercivity Hc. Surface defects are found to give rise to pinned magnetic domains correlated with typical hysteresis. Obviously, Hc and the formation of pits are due to misfit stress and substrate surface quality. Besides, it is shown that an increase of working temperature leads to smaller coercivities. (authors)

Fabrication and nano-imprintabilities of Zr-, Pd- and Cu-based glassy alloy thin films

International Nuclear Information System (INIS)

Takenaka, Kana; Saidoh, Noriko; Nishiyama, Nobuyuki; Inoue, Akihisa

2011-01-01

With the aim of investigating nano-imprintability of glassy alloys in a film form, Zr 49 Al 11 Ni 8 Cu 32 , Pd 39 Cu 29 Ni 13 P 19 and Cu 38 Zr 47 Al 9 Ag 6 glassy alloy thin films were fabricated on Si substrate by a magnetron sputtering method. These films exhibit a very smooth surface, a distinct glass transition phenomenon and a large supercooled liquid region of about 80 K, which are suitable for imprinting materials. Moreover, thermal nano-imprintability of these obtained films is demonstrated by using a dot array mold with a dot diameter of 90 nm. Surface observations revealed that periodic nano-hole arrays with a hole diameter of 90 nm were successfully imprinted on the surface of these films. Among them, Pd-based glassy alloy thin film indicated more precise pattern imprintability, namely, flatter residual surface plane and sharper hole edge. It is said that these glassy alloy thin films, especially Pd-based glassy alloy thin film, are one of the promising materials for fabricating micro-machines and nano-devices by thermal imprinting.

Bioplasmonic Alloyed Nanoislands Using Dewetting of Bilayer Thin Films.

Science.gov (United States)

Kang, Minhee; Ahn, Myeong-Su; Lee, Youngseop; Jeong, Ki-Hun

2017-10-25

Unlike monometallic materials, bimetallic plasmonic materials offer extensive benefits such as broadband tuning capability or high environmental stability. Here we report a broad range tuning of plasmon resonance of alloyed nanoislands by using solid-state dewetting of gold and silver bilayer thin films. Thermal dewetting after successive thermal evaporation of thin metal double-layer films readily forms AuAg-alloyed nanoislands with a precise composition ratio. The complete miscibility of alloyed nanoislands results in programmable tuning of plasmon resonance wavelength in a broadband visible range. Such extraordinary tuning capability opens up a new direction for plasmonic enhancement in biophotonic applications such as surface-enhanced Raman scattering or plasmon-enhanced fluorescence.

Surface Modification of C17200 Copper-Beryllium Alloy by Plasma Nitriding of Cu-Ti Gradient Film

Science.gov (United States)

Zhu, Y. D.; Yan, M. F.; Zhang, Y. X.; Zhang, C. S.

2018-03-01

In the present work, a copper-titanium film of gradient composition was firstly fabricated by the dual magnetron sputtering through power control and plasma nitriding of the film was then conducted to modify C17200 Cu alloy. The results showed that the prepared gradient Cu-Ti film by magnetron sputtering was amorphous. After plasma nitriding at 650 °C, crystalline Cu-Ti intermetallics appeared in the multi-phase coating, including CuTi2, Cu3Ti, Cu3Ti2 and CuTi. Moreover, even though the plasma nitriding duration of the gradient Cu-Ti film was only 0.5 h, the mechanical properties of the modified Cu surface were obviously improved, with the surface hardness enhanced to be 417 HV0.01, the wear rate to be 0.32 × 10-14 m3/Nm and the friction coefficient to be 0.075 at the load of 10 N, which are all more excellent than the C17200 Cu alloy. In addition, the wear mechanism also changed from adhesion wear for C17200 Cu substrate to abrasive wear for the modified surface.

Effect of electrolyte additives on performance of plasma electrolytic oxidation films formed on magnesium alloy AZ91D

International Nuclear Information System (INIS)

Duan, Hongping; Yan, Chuanwei; Wang, Fuhui

2007-01-01

Various plasma electrolytic oxidation (PEO) films were prepared on magnesium alloy AZ91D in a silicate bath with different additives such as phosphate, fluoride and borate. Effects of the additives on chemical composition and corrosion resistance of the PEO films were examined by means of scanning electron microscopy (SEM), potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) in 3.5% NaCl solution. The results showed that the PEO films obtained in solutions with both borate and fluoride had better corrosion resistance. In order to understand the corrosion mechanism of PEO films on magnesium alloy AZ91D, electronic property of the magnesium electrode with PEO films was studied by Mott-Schottky approach in a solution containing borate and chloride. The results indicated that magnesium electrodes with and without PEO films all exhibited n-type semiconducting property. However, in comparison with the magnesium electrode treated in solutions containing phosphate or borate, the electrode treated in solutions containing both borate and fluoride (M-film) had lower donor concentration and much negative flat band potential; therefore, the M-film had lower reactivity and higher corrosion resistance

Porous anodic film formation on an Al-3.5 wt% Cu alloy

Energy Technology Data Exchange (ETDEWEB)

Paez, M.A.; Bustos, O.; Thompson, G.E.; Skeldon, P.; Shimizu, K.; Wood, G.C.

2000-03-01

Anodic film growth has been undertaken on an electropolished Al-3.5 wt % Cu alloy to determine the influence of copper in solid solution on the anodizing behavior. At the commencement of anodizing of the electropolished alloy, in the presence of interfacial enrichment of copper, Al{sup 3+} and Cu{sup 2+} ions egress and O{sup 2{minus}} ion ingress proceed; film growth occurs at the alloy/film interface though O{sup 2{minus}} ion ingress, with outwardly mobile Al{sup 3+} and Cu{sup 2+} ions ejected at the film/electrolyte interface, and field-assisted dissolution proceeding at the bases of pores. Oxidation of copper, in the presence of the enriched layer, is also associated with O{sub 2} gas generation, leading to development of oxygen-filled voids. As a result of significant pressures in the voids, film rupture proceeds, with electrolyte access to the alloy, dissolution of the enriched interfacial layer and re-anodizing. The consequence of such processes in the development of anodic films of increased porosity and reduced efficiency of film formation compared with anodizing of superpure aluminum under similar conditions.

Corrosion resistance of multilayered magnesium phosphate/magnesium hydroxide film formed on magnesium alloy using steam-curing assisted chemical conversion method

International Nuclear Information System (INIS)

Ishizaki, Takahiro; Kudo, Ruriko; Omi, Takeshi; Teshima, Katsuya; Sonoda, Tsutomu; Shigematsu, Ichinori; Sakamoto, Michiru

2012-01-01

Anticorrosive multilayered films were successfully prepared on magnesium alloy AZ31 by chemical conversion treatment, followed by steam curing treatment. The crystal structures, chemical composition, surface morphologies, chemical bonding states of the film was characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and field emission scanning electron microscope (FE-SEM) measurements. All the films had thicknesses of ranging from 24 to 32 μm. The film had two layers that were composed of crystalline NH 4 MgPO 4 ·H 2 O, Mg 2 PO 4 OH·3H 2 O, Mg(OH) 2 and amorphous MgO. The outer layers include magnesium, oxygen, and phosphorous, and the inner layers include magnesium and oxygen. The corrosion resistant performances of the multilayered films in 5 wt% NaCl aqueous solution were investigated by electrochemical and gravimetric measurements. The potentiodynamic polarization curves revealed that the corrosion current density (j corr ) of all the film coated magnesium alloys decreased by more than four orders of magnitude as compared to that of the bare magnesium alloy, indicating that all the films had an inhibiting effect of corrosion reaction. Gravimetric measurements showed that the average corrosion rates obtained from the weight loss rates were estimated to be in the ranges of ca. 0.085–0.129 mm/y. American Society for Testing and Materials (ASTM) standard D 3359-02 cross cut tape test revealed that the adhesion of our anticorrosive multilayered film to the magnesium alloy surface was very good.

Synthesis and characterization of Cu–Al–Ni shape memory alloy multilayer thin films

Energy Technology Data Exchange (ETDEWEB)

Gómez-Cortés, J.F. [Dpt. Física Materia Condensada, Facultad de Ciencia y Tecnología, Universidad del País Vasco, Apdo. 644, 48080 Bilbao (Spain); San Juan, J., E-mail: jose.sanjuan@ehu.es [Dpt. Física Materia Condensada, Facultad de Ciencia y Tecnología, Universidad del País Vasco, Apdo. 644, 48080 Bilbao (Spain); López, G.A.; Nó, M.L. [Dpt. Física Aplicada II, Facultad de Ciencia y Tecnología, Universidad del País Vasco, Apdo. 644, 48080 Bilbao (Spain)

2013-10-01

Among active materials, shape memory alloys are well recognized for their work output density. Because of that, these alloys have attracted much attention to be used in micro/nano electromechanical systems. In the present work, the electron beam evaporation technique has been used to growth, by a multilayer method, two shape memory alloy thin films with different Cu–Al–Ni composition. Multilayers have been further thermally treated to produce the alloys by solid solution diffusion. The produced multilayers have been characterized and the presence of the martensite phase in the obtained thin films was studied. Furthermore, the influence of two different coatings onto the Si substrates, namely Si/SiO{sub 2} and Si/Si{sub 3}N{sub 4}, was investigated. Mechanically stable, not detaching from the substrates, Cu–Al–Ni shape memory alloy thin films, about 1 micrometre thick, showing a martensitic transformation have been produced. - Highlights: ► Multilayer thin films of Cu–Al–Ni shape memory alloys produced by e-beam evaporation. ► SiN{sub X} 200 nm thick coating is good for high quality Cu–Al–Ni shape memory thin films. ► Thermal treatment renders Cu–Al–Ni multilayer in homogeneous martensite thin film.

Magnetic x-ray linear dichroism of ultrathin Fe-Ni alloy films

Energy Technology Data Exchange (ETDEWEB)

Schumann, F.O.; Willis, R.F. [Pennsylvania State Univ., University Park, PA (United States); Goodman, K.W. [Lawrence Berkeley National Lab., CA (United States)] [and others

1997-04-01

The authors have studied the magnetic structure of ultrathin Fe-Ni alloy films as a function of Fe concentration by measuring the linear dichroism of the 3p-core levels in angle-resolved photoemission spectroscopy. The alloy films, grown by molecular-beam epitaxy on Cu(001) surfaces, were fcc and approximately four monolayers thick. The intensity of the Fe dichroism varied with Fe concentration, with larger dichroisms at lower Fe concentrations. The implication of these results to an ultrathin film analogue of the bulk Invar effect in Fe-Ni alloys will be discussed. These measurements were performed at the Spectromicroscopy Facility (Beamline 7.0.1) of the Advanced Light Source.

Studies on the growth of oxide films on alloy 800 and alloy 600 in lithiated water at high temperature

International Nuclear Information System (INIS)

Olmedo, A.M.; Bordon, R.

2007-01-01

In this work, the oxide films grown on Alloy 800 and Alloy 600 in lithiated (pH 25 C d egrees = 10.2-10.4) water at high temperature, with and without hydrogen overpressure (HO) and an initial oxygen dissolved in the water have been studied. The oxide films were grown at different temperatures (220-350 C degrees) and exposure times with HO, and at 315 C degrees without HO in static autoclaves. Some results are also reported for oxide layers grown on Alloy 800 coupons exposed in a high temperature loop during extended exposure times. The average oxide thickness was determined using descaling procedures. The morphology and composition of the oxide films were analyzed with scanning electron microscopy (SEM), EDS and X-ray diffraction (XRD). For both Alloys, at 350 C degrees with HO, the oxide layers were clearly composed of a double layer: an inner one of very small crystallites and an outer layer formed by bigger crystals scattered over the inner one. The analysis by X-ray diffraction indicated the presence of spinel structures like magnetite (Fe 3 O 4 ) and ferrites and/or nickel chromites. In this case the average oxide thickness was around 0.12 to 0.15 μm for both Alloys. Similar values were found at lower temperatures. The morphology of the oxide layer was similar at lower temperatures for Alloy 800, but a different morphology consisting of platelets or needles was found for Alloy 600. The oxide morphology found at 315 C degrees, without HO and with initial dissolved oxygen in the water, was also very different between both Alloys. The oxide film grown on Alloy 600 with an initial dissolved oxygen in the water, showed clusters of platelets forming structures like flowers that were dispersed on an rather homogeneous layer consisting of smaller platelets or needles. The average oxide film grown in this case was around 0.25 μm for Alloy 600 and 0.18 μm for Alloy 800. (author) [es

The Formation Mechanism and Corrosion Resistance of a Composite Phosphate Conversion Film on AM60 Alloy.

Science.gov (United States)

Chen, Jun; Lan, Xiangna; Wang, Chao; Zhang, Qinyong

2018-03-08

Magnesium alloy AM60 has high duc and toughness, which is expected to increase in demand for automotive applications. However, it is too active, and coatings have been extensively studied to prevent corrosion. In this work, a Ba-containing composite phosphate film has been prepared on the surface of AM60. The composition and formation mechanism of the film have been investigated using a scanning electronic microscope equipped with energy dispersive X-ray spectroscopy, Fourier transform infrared, X-ray photoelectron spectroscopy, and X-ray diffractometry tests. The corrosion resistance of the film has been measured by electrochemical and immersion tests. The results show that the deposition film has fully covered the substrate but there are some micro-cracks. The structure of the film is complex, and consists of MgHPO₄·3H₂O, MnHPO₄·2.25H₂O, BaHPO₄·3H₂O, BaMg₂(PO₄)₂, Mg₃(PO₄)₂·22H₂O, Ca₃(PO₄)₂·xH₂O, and some amorphous phases. The composite phosphate film has better anticorrosion performance than the AM60 and can protect the bare alloy from corrosion for more than 12 h in 0.6 M NaCl.

In vitro biocompatibility of Ti-Mg alloys fabricated by direct current magnetron sputtering.

Science.gov (United States)

Hieda, Junko; Niinomi, Mitsuo; Nakai, Masaaki; Cho, Ken

2015-09-01

Ti-xMg (x=17, 33, and 55 mass%) alloy films, which cannot be prepared by conventional melting processes owing to the absence of a solid-solution phase in the phase diagram, were prepared by direct current magnetron sputtering in order to investigate their biocompatibility. Ti and Mg films were also prepared by the same process for comparison. The crystal structures were examined by X-ray diffraction (XRD) analysis and the surfaces were analyzed by X-ray photoelectron spectroscopy. The Ti, Ti-xMg alloy, and Mg films were immersed in a 0.9% NaCl solution at 310 K for 7d to evaluate the dissolution amounts of Ti and Mg. In addition, to evaluate the formation ability of calcium phosphate in vitro, the Ti, Ti-xMg alloy, and Mg films were immersed in Hanks' solution at 310 K for 30 d. Ti and Mg form solid-solution alloys because the peaks attributed to pure Ti and Mg do not appear in the XRD patterns of any of the Ti-xMg alloy films. The surfaces of the Ti-17 Mg alloy and Ti-33 Mg alloy films contain Ti oxides and MgO, whereas MgO is the main component of the surface oxide of the Ti-55 Mg alloy and Mg films. The dissolution amounts of Ti from all films are below or near the detection limit of inductively coupled plasma-optical emission spectroscopy. On the other hand, the Ti-17 Mg alloy, Ti-33 Mg alloy, Ti-55 Mg alloy, and Mg films exhibit Mg dissolution amounts of approximately 2.5, 1.4, 21, and 41 μg/cm(2), respectively. The diffraction peaks attributed to calcium phosphate are present in the XRD patterns of the Ti-33 Mg alloy, Ti-55 Mg alloy, and Mg films after the immersion in Hanks' solution. Spherical calcium phosphate particles precipitate on the surface of the Ti-33 Mg film. However, many cracks are observed in the Ti-55 Mg film, and delamination of the film occurs after the immersion in Hanks' solution. The Mg film is dissolved in Hanks' solution and calcium phosphate particles precipitate on the glass substrate. Consequently, it is revealed that the Ti-33 Mg

Preparation of copper-beryllium alloys from Indian beryl

International Nuclear Information System (INIS)

Paul, C.M.; Sharma, B.P.; Subba Rao, K.S.; Rajadhyaksha, M.G.; Sundaram, C.V.

1975-01-01

The paper presents the results of laboratory-scale investigations on the preparation of copper-beryllium and aluminium beryllium master alloys starting from Indian beryl and adopting the fluoride process. The flowsheet involves: (1) conversion of the Be-values in beryl into water soluble sodium beryllium fluoride, (2) preparation of beryllium hydroxide by alkali treatment of aqueous Na 2 BeF 4 (3) conversion of Be(OH) 2 to (NH 4 ) 2 BeF 4 by treatment with NH 4 HF 2 (4) thermal decomposition of (NH 4 ) 2 BeF 4 to BeF 2 and (5) magnesium reduction of BeF 2 (without/with) the addition of copper/aluminium to obtain beryllium metal/alloys. The method has been successfully employed for the preparation of Cu-Be master alloys containing about 8% Be and free of Mg on a 200 gm scale. A1-80% Be master alloys have also been prepared by this method. Toxicity and health hazards associated with Be are discussed and the steps taken to ensure safe handling of Be are described. (author)

PREPARATION AND MAGNETIC-PROPERTIES OF AMORPHOUS FE1-XBX (15-LESS-THAN-OR-EQUAL-TO X LESS-THAN-40 ATMOSPHERIC PERCENT) ALLOY PARTICLES

DEFF Research Database (Denmark)

Linderoth, Søren; Mørup, S.

1992-01-01

Amorphous Fe1-xBx alloy particles have been prepared in aqueous solutions by reduction of Fe2+ ions to the metallic state by the use of NaBH4. It is demonstrated, that by changing the pH of the aqueous metal ion solution the amount of boron incorporated in the alloy particles can be varied between...... 15 and 28 at.%. Fe-57 Mossbauer spectra have been obtained at 10, 80 and 295 K. The hyperfine parameters for amorphous particles have been found to be similar to those found for ribbons and films prepared by the liquid-quench and sputtering techniques, respectively, though with a tendency...... for the magnetic hyperfine fields for the chemically prepared and sputter prepared alloys to deviate slightly from those for melt-spun samples. The magnetic hyperfine fields decrease linearly as a function of T3/2....

Development of an ion-beam sputtering system for depositing thin films and multilayers of alloys and compounds

International Nuclear Information System (INIS)

Gupta, Mukul; Gupta, Ajay; Phase, D.M.; Chaudhari, S.M.; Dasannacharya, B.A.

2002-01-01

An ion-beam sputtering (IBS) system has been designed and developed for preparing thin films and multilayers of various elements, alloys and compounds. The ion source used is a 3 cm diameter, hot-cathode Kaufman type 1.5 kV ion source. The system has been successfully tested with the deposition of various materials, and the deposition parameters were optimised for achieving good quality of thin films and multilayers. A systematic illustration of the versatility of the system to produce a variety of structures is done by depositing thin film of pure iron, an alloy film of Fe-Zr, a compound thin film of FeN, a multilayer of Fe-Ag and an isotopic multilayer of 57 FeZr/FeZr. Microstructural measurements on these films using X-ray and neutron reflectivity, atomic force microscopy (AFM), and X-ray diffraction are presented and discussed to reveal the quality of the microstructures obtained with the system. It is found that in general, the surface roughnesses of the film deposited by IBS are significantly smaller as compared to those for films deposited by e-beam evaporation. Further, the grain size of the IBS crystalline films is significantly refined as compared to the films deposited by e-beam evaporation. Grain refinement may be one of the reasons for reduced surface roughness. In the case of amorphous films, the roughness of the films does not increase appreciably beyond that of the substrate even after depositing thicknesses of several hundred angstroms

Compositional redistribution in alloy films under high-voltage electron microscope irradiation

Science.gov (United States)

Lam, Nghi Q.; Leaf, O. K.; Minkoff, M.

1983-10-01

The problem of nonequilibrium segregation in alloy films under high-voltage electron microscope (HVEM) irradiation at elevated temperatures is re-examined in the present work, taking into account the damage-rate gradients caused by radial variation in the electron flux. Axial and radial compositional redistributions in model solid solutions, representative of concentrated Ni-Cu, Ni-Al and Ni-Si alloys, were calculated as a function of time, temperature, and film thickness, using a kinetic theory of segregation in binary alloys. The numerical results were achieved by means of a new software package (DISPL2) for solving convection-diffusion-kinetics problems with general orthogonal geometries. It was found that HVEM irradiation-induced segregation in thin films consists of two stages. Initially, due to the proximity of the film surfaces as sinks for point defects, the usual axial segregation (to surfaces) occurs at relatively short irradiation times, and rapidly attains quasi-steady state. Then, radial segregation becomes more and more competitive, gradually affecting the kinetics of axial segregation. At a given temperature, the buildup time to steady state is much longer in the present situation than in the simple case of one-dimensional segregation with uniform defect production. Changes in the alloy composition occur in a much larger zone than the irradiated volume. As a result, the average alloy composition within the irradiated region can differ greatly from that of the unirradiated alloy. The present calculations may be useful in the interpretation of the kinetics of certain HVEM irradiation-induced processes in alloys.

Oromucosal film preparations: classification and characterization methods.

Science.gov (United States)

Preis, Maren; Woertz, Christina; Kleinebudde, Peter; Breitkreutz, Jörg

2013-09-01

Recently, the regulatory authorities have enlarged the variety of 'oromucosal preparations' by buccal films and orodispersible films. Various film preparations have entered the market and pharmacopoeias. Due to the novelty of the official monographs, no standardized characterization methods and quality specifications are included. This review reports the methods of choice to characterize oromucosal film preparations with respect to biorelevant characterization and quality control. Commonly used dissolution tests for other dosage forms are not transferable for films in all cases. Alternatives and guidance on decision, which methods are favorable for film preparations are discussed. Furthermore, issues about requirements for film dosage forms are reflected. Oromucosal film preparations offer a wide spectrum of opportunities. There are a lot of suggestions in the literature on how to control the quality of these innovative products, but no standardized tests are available. Regulatory authorities need to define the standards and quality requirements more precisely.

Vanadium Oxide Thin Films Alloyed with Ti, Zr, Nb, and Mo for Uncooled Infrared Imaging Applications

Science.gov (United States)

Ozcelik, Adem; Cabarcos, Orlando; Allara, David L.; Horn, Mark W.

2013-05-01

Microbolometer-grade vanadium oxide (VO x ) thin films with 1.3 Nb, Mo, and Zr using a second gun and radiofrequency (RF) reactive co-sputtering to probe the effects of the transition metals on the film charge transport characteristics. The results reveal that the temperature coefficient of resistance (TCR) and resistivity are unexpectedly similar for alloyed and unalloyed films up to alloy compositions in the ˜20 at.% range. Analysis of the film structures for the case of the 17% Nb-alloyed film by glancing-angle x-ray diffraction and transmission electron microscopy shows that the microstructure remains even with the addition of high concentrations of alloy metal, demonstrating the robust character of the VO x films to maintain favorable electrical transport properties for bolometer applications. Postdeposition thermal annealing of the alloyed VO x films further reveals improvement of electrical properties compared with unalloyed films, indicating a direction for further improvements in the materials.

Formation of SmFe{sub 5}(0001) ordered alloy thin films on Cu(111) single-crystal underlayers

Energy Technology Data Exchange (ETDEWEB)

Yabuhara, Osamu; Ohtake, Mitsuru; Nukaga, Yuri; Futamoto, Masaaki [Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551 (Japan); Kirino, Fumiyoshi, E-mail: yabuhara@futamoto.elect.chuo-u.ac.j [Graduate School of Fine Arts, Tokyo National University of Fine Arts and Music, 12-8 Ueno-koen, Taito-ku, Tokyo 110-8714 (Japan)

2010-01-01

SmFe{sub 5}(0001) single-crystal thin films are prepared by molecular beam epitaxy employing Cu(111) single-crystal underlayers on MgO(111) substrates. The Cu atoms diffuse into the Sm-Fe layer and substitute the Fe sites in SmFe{sub 5} structure forming an alloy compound of Sm(Fe,Cu){sub 5}. The Sm(Fe,Cu){sub 5} film is more Cu enriched with increasing the substrate temperature. The Cu underlayer plays an important role in assisting the formation of the ordered phase.

The microstructure, mechanical and friction properties of protective diamond like carbon films on magnesium alloy

Science.gov (United States)

Zou, Y. S.; Wu, Y. F.; Yang, H.; Cang, K.; Song, G. H.; Li, Z. X.; Zhou, K.

2011-12-01

Protective hard coatings deposited on magnesium alloys are believed to be effective for overcoming their poor wear properties. In this work, diamond-like carbon (DLC) films as hard protective films were deposited on AZ91 magnesium alloy by arc ion plating under negative pulse bias voltages ranging from 0 to -200 V. The microstructure, composition and mechanical properties of the DLC films were analyzed by scanning electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy and nanoindentation. The tribological behavior of uncoated and coated AZ91 magnesium alloy was investigated using a ball-on-disk tribotester. The results show that the negative pulse bias voltage used for film deposition has a significant effect on the sp3 carbon content and mechanical properties of the deposited DLC films. A maximum sp3 content of 33.3% was obtained at -100 V, resulting in a high hardness of 28.6 GPa and elastic modulus of 300.0 GPa. The DLC films showed very good adhesion to the AZ91 magnesium alloy with no observable cracks and delamination even during friction testing. Compared with the uncoated AZ91 magnesium alloy, the magnesium alloy coated with DLC films exhibits a low friction coefficient and a narrow, shallow wear track. The wear resistance and surface hardness of AZ91 magnesium alloy can be significantly improved by coating a layer of DLC protective film due to its high hardness and low friction coefficient.

The microstructure, mechanical and friction properties of protective diamond like carbon films on magnesium alloy

International Nuclear Information System (INIS)

Zou, Y.S.; Wu, Y.F.; Yang, H.; Cang, K.; Song, G.H.; Li, Z.X.; Zhou, K.

2011-01-01

Protective hard coatings deposited on magnesium alloys are believed to be effective for overcoming their poor wear properties. In this work, diamond-like carbon (DLC) films as hard protective films were deposited on AZ91 magnesium alloy by arc ion plating under negative pulse bias voltages ranging from 0 to -200 V. The microstructure, composition and mechanical properties of the DLC films were analyzed by scanning electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy and nanoindentation. The tribological behavior of uncoated and coated AZ91 magnesium alloy was investigated using a ball-on-disk tribotester. The results show that the negative pulse bias voltage used for film deposition has a significant effect on the sp 3 carbon content and mechanical properties of the deposited DLC films. A maximum sp 3 content of 33.3% was obtained at -100 V, resulting in a high hardness of 28.6 GPa and elastic modulus of 300.0 GPa. The DLC films showed very good adhesion to the AZ91 magnesium alloy with no observable cracks and delamination even during friction testing. Compared with the uncoated AZ91 magnesium alloy, the magnesium alloy coated with DLC films exhibits a low friction coefficient and a narrow, shallow wear track. The wear resistance and surface hardness of AZ91 magnesium alloy can be significantly improved by coating a layer of DLC protective film due to its high hardness and low friction coefficient.

The microstructure, mechanical and friction properties of protective diamond like carbon films on magnesium alloy

Energy Technology Data Exchange (ETDEWEB)

Zou, Y.S., E-mail: yshzou75@gmail.com [School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu, 210094 (China); Wu, Y.F.; Yang, H.; Cang, K. [School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu, 210094 (China); Song, G.H. [School of Materials Science and Engineering, Shenyang University of Technology, Shenyang, Liaoning, 110178 (China); Li, Z.X.; Zhou, K. [School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu, 210094 (China)

2011-12-01

Protective hard coatings deposited on magnesium alloys are believed to be effective for overcoming their poor wear properties. In this work, diamond-like carbon (DLC) films as hard protective films were deposited on AZ91 magnesium alloy by arc ion plating under negative pulse bias voltages ranging from 0 to -200 V. The microstructure, composition and mechanical properties of the DLC films were analyzed by scanning electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy and nanoindentation. The tribological behavior of uncoated and coated AZ91 magnesium alloy was investigated using a ball-on-disk tribotester. The results show that the negative pulse bias voltage used for film deposition has a significant effect on the sp{sup 3} carbon content and mechanical properties of the deposited DLC films. A maximum sp{sup 3} content of 33.3% was obtained at -100 V, resulting in a high hardness of 28.6 GPa and elastic modulus of 300.0 GPa. The DLC films showed very good adhesion to the AZ91 magnesium alloy with no observable cracks and delamination even during friction testing. Compared with the uncoated AZ91 magnesium alloy, the magnesium alloy coated with DLC films exhibits a low friction coefficient and a narrow, shallow wear track. The wear resistance and surface hardness of AZ91 magnesium alloy can be significantly improved by coating a layer of DLC protective film due to its high hardness and low friction coefficient.

Electrochemical characterization of oxide film formed at high temperature on Alloy 690

Energy Technology Data Exchange (ETDEWEB)

Abraham, Geogy J., E-mail: gja@barc.gov.in [Materials Science Division, BARC, Mumbai 400 085 (India); Bhambroo, Rajan [Deptt. of Metallurgical Engg. and Mat. Sci., IIT Bombay, Mumbai 400 076 (India); Kain, V. [Materials Science Division, BARC, Mumbai 400 085 (India); Shekhar, R. [CCCM, BARC, Hyderabad 500 062 (India); Dey, G.K. [Materials Science Division, BARC, Mumbai 400 085 (India); Raja, V.S. [Deptt. of Metallurgical Engg. and Mat. Sci., IIT Bombay, Mumbai 400 076 (India)

2012-02-15

Highlights: Black-Right-Pointing-Pointer GD-QMS studies of high temperature oxide film formed on Alloy 690. Black-Right-Pointing-Pointer Defect density reduced with increase in temperature. Black-Right-Pointing-Pointer Electrochemical behaviour of oxide film correlated to the Cr-content in oxide. - Abstract: High temperature passivation studies on Alloy 690 were carried out in lithiated water at 250 Degree-Sign C, 275 Degree-Sign C and 300 Degree-Sign C for 72 h. The passive films were characterized by glow discharge-quadrupole mass spectroscopy (GD-QMS) for compositional variation across the depth and micro laser Raman spectroscopy for oxide composition on the surface. The defect density in the oxide films was established from the Mott-Schottky analysis using electrochemical impedance spectroscopy. Electrochemical experiments at room temperature in chloride medium revealed best passivity behaviour by the oxide film formed at 300 Degree-Sign C for 72 h. The electrochemical studies were correlated to the chromium (and oxygen) content of the oxide films. Autoclaving at 300 Degree-Sign C resulted in the best passive film formation on Alloy 690 in lithiated water.

Preparation of copper-beryllium alloys from Indian beryl

International Nuclear Information System (INIS)

Paul, C.M.; Sharma, B.P.; Subba Rao, K.S.; Rajadhyaksha, M.G.; Sundaram, C.V.

1975-01-01

The report presents the results of laboratory scale investigations on the preparation of copper-beryllium and aluminium-beryllium master alloys starting from Indian beryl and adopting the fluoride process. The flow-sheet involves : (1) conversion of the Be-values in beryl into water soluble sodium beryllium fluoride (2) preparation of beryllium hydroxide by alkali treatment of aqueous Na 2 BeF 4 (3) conversion of Be(OH) 2 to (NH 4 ) 2 BeF 4 by treatment with NH 4 HF 2 (4) thermal decomposition of (NH 4 ) 2 BeF 4 to BeF 2 and (5) magnesium reduction of BeF 2 (with the addition of copper/aluminium) to obtain beryllium alloys. The method has been successfully employed for the preparation of Cu-Be master alloys containing about 8% Be and free of Mg on a 200 gm scale. An overall Be-recovery of about 80% has been achieved. Al-8% Be master alloys have also been prepared by this method. Toxicity and health hazards associated with Be are discussed and the steps taken to ensure safe handling of Be are described. (author)

Interface alloying in multilayer thin films using polarized neutron reflectometry

International Nuclear Information System (INIS)

Basu, Saibal

2013-01-01

Polarized Neutron Reflectometry (PNR) is an excellent tool to probe magnetic depth profile in multilayer thin film samples. In case of multilayer films with alternating magnetic and non-magnetic layers, PNR can provide magnetic depth profile at the interfaces with better than nanometer resolution. Using PNR and Xray Reflectometry (XRR) together one can obtain chemical composition and magnetic structure, viz. magnetic moment density at interfaces in multilayer films. We have used these two techniques to obtain kinetics of alloy formation at the interfaces and the magnetic nature of the alloy at the interfaces in several important thin films with magnetic/non-magnetic bilayers. These include Ni/Ti, Ni/Al and Si/Ni pairs. Results obtained from these studies will be presented in this talk. (author)

Influence of structural disorder on the optical and transport properties of Co0.50 Ti0.50 alloy films

International Nuclear Information System (INIS)

Kim, Ki Won; Lee, Y. P.; Rhee, Joo Yull; Kudryavtsev, Yuriy V.; Ri, H. C.

2000-01-01

Co 0.50 Ti 0.50 alloy films with a total thickness of about 100 nm were prepared by flash evaporation of the crushed alloy powders onto heated (730 K for the ordered state) and LN 2 -cooled (150 K for the disordered state) substrates. Structural analysis of the films was performed by suing transmission electron microscopy. The optical conductivity (OC) of the samples was measured at room temperature in a spectral range of 265 -2500 nm (4.7 - 0.5 eV). The resistivity measurements were carried out by using the four-probe technique in a temperature range of 4.2 - 300 K. The experimental OC spectra for the Co 0.50 Ti 0.50 alloys show the most significant change in the infrared region upon the order-disorder transformation. The structural disorder in the Co 0.50 Ti 0.50 alloy film leads to a change in the sign of the temperature coefficient of the resistivity from positive to negative. The observed changes in the optical properties and the temperature dependences of resistivity caused by the order-disorder structural transition are analyzed in the framework of the lattice symmetry and the electronic structure of the ordered CoTi compound

Formation of barrier-type anodic films on ZE41 magnesium alloy in a fluoride/glycerol electrolyte

International Nuclear Information System (INIS)

Hernández-López, J.M.; Němcová, A.; Zhong, X.L.; Liu, H.; Arenas, M.A.; Haigh, S.J.; Burke, M.G.; Skeldon, P.; Thompson, G.E.

2014-01-01

Highlights: • Barrier anodic films formed on ZE41 Mg alloy in glycerol/fluoride electrolyte. • Films contain oxygen and fluorine species; formation ratio ∼1.3 nm V −1 . • Nanocrystalline film structure, with MgO and MgF 2. • Zinc enrichment in alloy beneath anodic film. • Modified film formed above Mg-Zn-RE second phase. - Abstract: Barrier-type, nanocrystalline anodic films have been formed on a ZE41 magnesium alloy under a constant current density of 5 mA cm −2 in a glycerol/fluoride electrolyte, containing 5 vol.% of added water, at 293 K. The films contain magnesium, fluorine and oxygen as the major species, and lower amounts of alloying element species. The films grow at an efficiency of ∼0.8 to 0.9, with a formation ratio in the range of ∼1.2 to 1.4 nm V −1 at the matrix regions and with a ratio of ∼1.8 nm V −1 at Mg-Zn-RE second phase. At the former regions, rare earth species are enriched at the film surface and zinc is enriched in the alloy. A carbon- and oxygen-rich band within the film suggests that the films grow at the metal/film and film/electrolyte interfaces

Rhenium Alloys as Ductile Substrates for Diamond Thin-Film Electrodes.

Science.gov (United States)

Halpern, Jeffrey M; Martin, Heidi B

2014-02-01

Molybdenum-rhenium (Mo/Re) and tungsten-rhenium (W/Re) alloys were investigated as substrates for thin-film, polycrystalline boron-doped diamond electrodes. Traditional, carbide-forming metal substrates adhere strongly to diamond but lose their ductility during exposure to the high-temperature (1000°C) diamond, chemical vapor deposition environment. Boron-doped semi-metallic diamond was selectively deposited for up to 20 hours on one end of Mo/Re (47.5/52.5 wt.%) and W/Re (75/25 wt.%) alloy wires. Conformal diamond films on the alloys displayed grain sizes and Raman signatures similar to films grown on tungsten; in all cases, the morphology and Raman spectra were consistent with well-faceted, microcrystalline diamond with minimal sp 2 carbon content. Cyclic voltammograms of dopamine in phosphate-buffered saline (PBS) showed the wide window and low baseline current of high-quality diamond electrodes. In addition, the films showed consistently well-defined, dopamine electrochemical redox activity. The Mo/Re substrate regions that were uncoated but still exposed to the diamond-growth environment remained substantially more flexible than tungsten in a bend-to-fracture rotation test, bending to the test maximum of 90° and not fracturing. The W/Re substrates fractured after a 27° bend, and the tungsten fractured after a 21° bend. Brittle, transgranular cleavage fracture surfaces were observed for tungsten and W/Re. A tension-induced fracture of the Mo/Re after the prior bend test showed a dimple fracture with a visible ductile core. Overall, the Mo/Re and W/Re alloys were suitable substrates for diamond growth. The Mo/Re alloy remained significantly more ductile than traditional tungsten substrates after diamond growth, and thus may be an attractive metal substrate for more ductile, thin-film diamond electrodes.

Microstructure and protection characteristics of the naturally formed oxide films on Mg–xZn alloys

International Nuclear Information System (INIS)

Song, Yingwei; Han, En-Hou; Dong, Kaihui; Shan, Dayong; Yim, Chang Dong; You, Bong Sun

2013-01-01

Highlights: •The oxide films on Mg–xZn alloys consist of similar chemical composition. •The higher Zn content results in the thicker but higher defect of the oxide films. •The oxide films exhibit different protection performance under various potentials. -- Abstract: The naturally formed oxide films on Mg–2Zn and Mg–5Zn alloys were investigated by atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and electrochemical measurements. The oxide films on the both alloys present a similar chemical composition, consisting of surface layer of basic magnesium carbonate and MgO following with MgO and ZnO, but the oxide film on Mg–5Zn is thicker and contains more defects. The protection performance of the oxide film on Mg–5Zn is worse under open circuit potential but better in a suitable anodic potential scope compared with that on Mg–2Zn alloy

The Formation Mechanism and Corrosion Resistance of a Composite Phosphate Conversion Film on AM60 Alloy

Science.gov (United States)

Lan, Xiangna; Wang, Chao; Zhang, Qinyong

2018-01-01

Magnesium alloy AM60 has high duc and toughness, which is expected to increase in demand for automotive applications. However, it is too active, and coatings have been extensively studied to prevent corrosion. In this work, a Ba-containing composite phosphate film has been prepared on the surface of AM60. The composition and formation mechanism of the film have been investigated using a scanning electronic microscope equipped with energy dispersive X-ray spectroscopy, Fourier transform infrared, X-ray photoelectron spectroscopy, and X-ray diffractometry tests. The corrosion resistance of the film has been measured by electrochemical and immersion tests. The results show that the deposition film has fully covered the substrate but there are some micro-cracks. The structure of the film is complex, and consists of MgHPO4·3H2O, MnHPO4·2.25H2O, BaHPO4·3H2O, BaMg2(PO4)2, Mg3(PO4)2·22H2O, Ca3(PO4)2·xH2O, and some amorphous phases. The composite phosphate film has better anticorrosion performance than the AM60 and can protect the bare alloy from corrosion for more than 12 h in 0.6 M NaCl. PMID:29518038

Nanocrystalline soft ferromagnetic Ni-Co-P thin film on Al alloy by low temperature electroless deposition

International Nuclear Information System (INIS)

Aal, A. Abdel; Shaaban, A.; Hamid, Z. Abdel

2008-01-01

Soft ferromagnetic ternary Ni-Co-P films were deposited onto Al 6061 alloy from low temperature Ni-Co-P electroless plating bath. The effect of deposition parameters, such as time and pH, on the plating rate of the deposit were examined. The results showed that the plating rate is a function of pH bath and the highest coating thickness can be obtained at pH value from 8 to10. The surface morphology, phase structure and the magnetic properties of the prepared films have been investigated using scanning electron microscopy (SEM), X-ray diffraction analysis (XRD) and vibrating magnetometer device (VMD), respectively. The deposit obtained at optimum conditions showed compact and smooth with nodular grains structure and exhibited high magnetic moments and low coercivety. Potentiodynamic polarization corrosion tests were used to study the general corrosion behavior of Al alloys, Ni-P and Ni-Co-P coatings in 3.5% NaCl solution. It was found that Ni-Co-P coated alloy demonstrated higher corrosion resistance than Ni-P coating containing same percent of P due to the Co addition. The Ni-Co-P coating with a combination of high corrosion resistance, high hardness and excellent magnetic properties would be expected to enlarge the applications of the aluminum alloys

Comparative study of Cu-Zr and Cu-Ru alloy films for barrier-free Cu metallization

International Nuclear Information System (INIS)

Wang Ying; Cao Fei; Zhang Milin; Liu Yuntao

2011-01-01

The properties of Cu-Zr and Cu-Ru alloy films were comparatively studied to evaluate their potential use as alloying elements. Cu alloy films were deposited on SiO 2 /Si substrates by magnetron sputtering. Samples were subsequently annealed and analyzed by four-point probe measurement, X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy and Auger electron spectroscopy. X-ray diffraction data suggest that Cu film has preferential (111) crystal orientation and no extra peak corresponding to any compound of Cu, Zr, Ru, and Si. According to transmission electron microscopy results, Cu grains grow in size for both systems but the grain sizes of the Cu alloy films are smaller than that of pure Cu films. These results indicate that Cu-Zr film is suitable for advanced barrier-free metallization in terms of interfacial stability and lower resistivity.

Formation and Corrosion Resistance of Mg-Al Hydrotalcite Film on Mg-Gd-Zn Alloy

Science.gov (United States)

Ba, Z. X.; Dong, Q. S.; Kong, S. X.; Zhang, X. B.; Xue, Y. J.; Chen, Y. J.

2017-06-01

An environment-friendly technique for depositing a Mg-Al hydrotalcite (HT) (Mg6Al2(OH)16-CO3ṡ4H2O) conversion film was developed to protect the Mg-Gd-Zn alloy from corrosion. The morphology and chemical compositions of the film were analyzed by scanning electronic microscope (SEM) equipped with energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and Raman spectroscopy (RS), respectively. The electrochemical test and hydrogen evolution test were employed to evaluate the biocorrosion behavior of Mg-Gd-Zn alloy coated with the Mg-Al HT film in the simulated body fluid (SBF). It was found that the formation of Mg-Al HT film was a transition from amorphous precursor to a crystalline HT structure. The HT film can effectively improve the corrosion resistance of magnesium alloy. It indicates that the process provides a promising approach to modify Mg-Gd-Zn alloy.

CIGS thin film solar cell prepared by reactive co-sputtering

Science.gov (United States)

Kim, Jeha; Lee, Ho-Sub; Park, Nae-Man

2013-09-01

The reactive co-sputtering was developed as a new way of preparing high quality CuInGaSe2(CIGS) films from two sets of targets; Cu0.6Ga 0.4 and Cu0.4In0.6 alloy and Cu and (In0.7Ga0.3)2Se3 compound targets. During sputtering, Cu, In, Ga metallic elements as well as the compound materials were reacted to form CIGS simultaneously in highly reactive elemental Se atmosphere generated by a thermal cracker. CIGS layer had been grown on Mo/soda-lime glass(SLG) at 500°C. For both sets of targets, we controlled the composition of CIGS thin film by changing the RF power for target components. All the films showed a preferential (112) orientation as observed from X-ray diffraction analysis. The composition ratios of CIGS were easily set to 0.71-0.95, 0.10-0.30 for [Cu]/[III] and [Ga]/[III], respectively. The grain size and the surface roughness of a CIGS film increased as the [Cu]/[III] ratios increased. The solar cells were fabricated using a standard base line process in the device structure of grid/ITO/i-ZnO/CdS/CIGS/Mo/ SLG. The best performance was obtained the performance of Voc = 0.45 V, Jsc =35.6, FF = 0.535, η = 8.6% with a 0.9 μm-CIGS solar cell from alloy targets while Voc = 0.54 V, Jsc =30.8, FF = 0.509, η = 8.5% with a 0.8 μm-CIGS solar cell from Cu and (In0.7Ga0.3)2Se3.

Stress evolution during and after sputter deposition of thin Cu Al alloy films

Science.gov (United States)

Pletea, M.; Wendrock, H.; Kaltofen, R.; Schmidt, O. G.; Koch, R.

2008-06-01

The stress evolution during and after sputter deposition of thin Cu-Al alloy films containing 1 and 2 at.% Al onto oxidized Si(100) substrates has been studied up to thicknesses of 300 nm by means of in situ substrate curvature measurements. In order to correlate stress and morphology, the microstructure was investigated by focused ion beam microscopy, scanning electron microscopy, and atomic force microscopy. The evolution of the stress and microstructure of the Cu-Al alloy films is similar to that for sputtered pure Cu films. Film growth proceeds in the Volmer-Weber mode, typical for high mobility metals. It is characterized by nucleation, island, percolation, and channel stages before the films become continuous, as well as lateral grain growth in the compact films. With increasing Al content the overall atom mobility and, thus, the average grain size of the alloy films are reduced. Increase of the sputter pressure from 0.5 to 2 Pa leads to films with larger grain size, rougher surface morphology and higher electrical resistivity.

Electrosynthesized polyaniline for the corrosion protection of aluminum alloy 2024-T3

Directory of Open Access Journals (Sweden)

Huerta-Vilca Domingo

2003-01-01

Full Text Available Adherent polyaniline films on aluminum alloy 2024-T3 have been prepared by electrodeposition from aniline containing oxalic acid solution. The most appropriate method to prepare protective films was a successive galvanostatic deposition of 500 seconds. With this type of film, the open circuit potential of the coating shifted around 0.065V vs. SCE compared to the uncoated alloy. The polyaniline coatings can be considered as candidates to protect copper-rich (3 - 5% aluminum alloys by avoiding the galvanic couple between re-deposited copper on the surface and the bulk alloy. The performance of the polyaniline films was verified by immersion tests up to 2.5 months. It was good with formation of some aluminum oxides due to electrolyte permeation so, in order to optimize the performance a coating formulation would content an isolation topcoat.

Effect of performance of Zr-Y alloy target on thin film deposition technology

International Nuclear Information System (INIS)

Pan Qianfu; Liu Chaohong; Jiang Mingzhong; Yin Changgeng

2011-01-01

Yttria-stabilized zirconia (YSZ) films are synthesized on corrosion resistant plates by pulsed bias arc ion plating. The arc starting performance and the stability of thin film deposition is explored by improving the uniformity and compactibility of Zr-Y alloy target. The property of Zr-Y alloy target and depositional thin films were measured with the optical microscope, scanning electron microscope, X-ray diffractometer. The result shows that the target with hot rolling and annealing has a good arc starting performance and stability of thin film deposition, and the depositional thin films made of Yttria and amorphous zirconia are homogeneous and compact. (authors)

Spray pyrolysis process for preparing superconductive films

International Nuclear Information System (INIS)

Hsu, H.M.; Yee, I.Y.

1991-01-01

This paper describes a spray pyrolysis method for preparing thin superconductive film. It comprises: preparing a spray pyrolysis solution comprising Bi,Sr,Ca and Cu metals in a solvent; heating a substrate to a first temperature; spraying the solution onto the heated substrate to form a film thereon; heating the film and substrate to a second temperature of about 700 degrees-825 degrees C, the second temperature being higher than the first temperature; heating the film and substrate to a third temperature of about 870 degrees-890 degrees C to melt the film; once the film and substrate reach the third temperature, further heat treating the film and substrate; cooling the film and substrate to ambient temperature. This patent also describes a spray pyrolysis method for preparing thin superconductive films. It comprises: preparing a spray pyrolysis solution comprising Bi, Ca and Cu metals and fluxing agent in a solvent; heating a substrate to a first temperature; spraying the solution onto the heated substrate to form a film thereon; heating the film and substrate to a second temperature about 700 degrees-825 degrees C, the second temperature being higher than the first temperature; heating the film and substrate at a third temperature about 840 degrees-860 degrees C; and cooling the film and substrate to ambient temperature

Preparation of thin vyns films

International Nuclear Information System (INIS)

Blanc, R.; Chedin, P.; Gizon, A.

1965-01-01

The fabrication of thin films of VYNS resin (copolymer of chloride and vinyl acetate) of superficial density from 3 to 50 μg/cm 2 with solutions in cyclohexanone is presented. Study and discussion of some properties compared with formvar film (polyvinyl formals). It appears that both can be used as source supports but formvar films are prepared more easily and more quickly, in addition they withstand higher temperatures. The main quality of VYNS is that they can be easily separated even several days after their preparation [fr

Preparation and mechanical properties of edible rapeseed protein films.

Science.gov (United States)

Jang, Sung-Ae; Lim, Geum-Ok; Song, Kyung Bin

2011-03-01

Edible films were manufactured from rapeseed oil extraction residues. To prepare rapeseed protein (RP) films, various concentrations of plasticizers and emulsifiers were incorporated into the preparation of a film-forming solution. The optimal conditions for the preparation of the RP film were 2% sorbitol/0.5% sucrose as plasticizer and 1.5% polysorbate 20 as an emulsifier. In addition, RP blend films were prepared. Gelidium corneum or gelatin was added to improve the physical properties of the RP film, and the highest tensile strength value of the films was 53.45 MPa for the 3% RP/4% gelatin film. Our results suggest that the RP-gelatin blend film is suitable for applications in food packaging. Edible RP films prepared in the present investigation can be applied in food packaging.

Semiconductor properties and protective role of passive films of iron base alloys

International Nuclear Information System (INIS)

Fujimoto, Shinji; Tsuchiya, Hiroaki

2007-01-01

Semiconductor properties of passive films formed on the Fe-18Cr alloy in a borate buffer solution (pH = 8.4) and 0.1 M H 2 SO 4 solution were examined using a photoelectrochemical spectroscopy and an electrochemical impedance spectroscopy. Photo current reveals two photo action spectra that derived from outer hydroxide and inner oxide layers. A typical n-type semiconductor behaviour is observed by both photo current and impedance for the passive films formed in the borate buffer solution. On the other hand, a negative photo current generated, the absolute value of which decreased as applied potential increased in the sulfuric acid solution. This indicates that the passive film behaves as a p-type semiconductor. However, Mott-Schottky plot revealed the typical n-type semiconductor property. It is concluded that the passive film on the Fe-18Cr alloy formed in the borate buffer solution is composed of both n-type outer hydroxide and inner oxide layers. On the other hand, the passive film of the Fe-18Cr alloy in the sulphuric acid consists of p-type oxide and n-type hydroxide layers. The behaviour of passive film growth and corrosion was discussed in terms of the electronic structure in the passive film

Preparation of a high strength Al–Cu–Mg alloy by mechanical alloying and press-forming

International Nuclear Information System (INIS)

Tang Huaguo; Cheng Zhiqiang; Liu Jianwei; Ma Xianfeng

2012-01-01

Highlights: ► A high strength aluminum alloy of Al–2 wt.%Mg–2 wt.%Cu has been prepared by mechanical alloying and press-forming. ► The alloy only consists of solid solution α-Al. ► The grains size of α-Al was about 300 nm–5 μm. ► The solid solution strengthening and the grain refinement strengthening are the main reasons for such a high strength. - Abstract: A high strength aluminum alloy, with the ratio of 96 wt.%Al–2 wt.%Mg–2 wt.%Cu, has been prepared by mechanical alloying and press-forming. The alloy exhibited a high tensile strength of 780 MPa and a high microhardness of 180 HV. X-ray diffraction characterizations confirmed that the alloy only consists of a solid solution α-Al. Microstructure characterizations revealed that the grain size of α-Al was about 300 nm–5 μm. The solid solution strengthening and the grain refinement strengthening were considered to be the reason for such a high strength.

Preparation of a high strength Al-Cu-Mg alloy by mechanical alloying and press-forming

Energy Technology Data Exchange (ETDEWEB)

Tang Huaguo [State Key Laboratory of Rare Earth Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Cheng Zhiqiang [College of Resources and Environment, Jilin Agricultural University, Changchun 130118 (China); Liu Jianwei [State Key Laboratory of Rare Earth Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Ma Xianfeng, E-mail: xfma@ciac.jl.cn [State Key Laboratory of Rare Earth Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

2012-07-30

Highlights: Black-Right-Pointing-Pointer A high strength aluminum alloy of Al-2 wt.%Mg-2 wt.%Cu has been prepared by mechanical alloying and press-forming. Black-Right-Pointing-Pointer The alloy only consists of solid solution {alpha}-Al. Black-Right-Pointing-Pointer The grains size of {alpha}-Al was about 300 nm-5 {mu}m. Black-Right-Pointing-Pointer The solid solution strengthening and the grain refinement strengthening are the main reasons for such a high strength. - Abstract: A high strength aluminum alloy, with the ratio of 96 wt.%Al-2 wt.%Mg-2 wt.%Cu, has been prepared by mechanical alloying and press-forming. The alloy exhibited a high tensile strength of 780 MPa and a high microhardness of 180 HV. X-ray diffraction characterizations confirmed that the alloy only consists of a solid solution {alpha}-Al. Microstructure characterizations revealed that the grain size of {alpha}-Al was about 300 nm-5 {mu}m. The solid solution strengthening and the grain refinement strengthening were considered to be the reason for such a high strength.

Work function of oxygen exposed lead and lead/indium alloy films

International Nuclear Information System (INIS)

Gundlach, K.H.; Hellemann, H.P.; Hoelzl, J.

1982-01-01

The effect of indium in superconducting tunnel junctions with lead/indium alloy base electrodes is investigated by measuring the vacuum work function of lead, indium, and lead/indium alloy films. It is found that the anomalous decrease of the work function of lead upon exposure to oxygen, explained by the penetration of oxygen into the inner surface of the lead film, is reversed into a slight increase in work function when some indium is added to the lead. This result indicates that the addition of indium provides a protection by suppressing the penetration of oxygen (and probably other gases) into the interior of the thin film

Note: Durability analysis of optical fiber hydrogen sensor based on Pd-Y alloy film.

Science.gov (United States)

Huang, Peng-cheng; Chen, You-ping; Zhang, Gang; Song, Han; Liu, Yi

2016-02-01

The Pd-Y alloy sensing film has an excellent property for hydrogen detection, but just for one month, the sensing film's property decreases seriously. To study the failure of the sensing film, the XPS spectra analysis was used to explore the chemical content of the Pd-Y alloy film, and analysis results demonstrate that the yttrium was oxidized. The paper presented that such an oxidized process was the potential reason of the failure of the sensing film. By understanding the reason of the failure of the sensing film better, we could improve the manufacturing process to enhance the property of hydrogen sensor.

Structural evolution in films of alloy Zn70Al27Cu3 (ZA27)

International Nuclear Information System (INIS)

Zhu, Y.H.; Lee, W.B.; Mei, Z.; To, S.; Sze, Y.K.

2005-01-01

Films of alloy ZA27 were produced using electron deposition technique. Structural evolution and phase decomposition of the films were studied. It was found that the alloy films were relatively stable because of a strong preferred crystal orientation of the nano-phases. The dependence of nano-phase stability on the Zn content and the preferred crystal orientation is discussed from point of view of Gibbs free energy

Microstructure and corrosion resistance of a fluorosilane modified silane-graphene film on 2024 aluminum alloy

Science.gov (United States)

Dun, Yuchao; Zhao, Xuhui; Tang, Yuming; Dino, Sahib; Zuo, Yu

2018-04-01

Heptadecafluorodecyl trimethoxysilane (FAS-17) was incorporated into γ-(2,3-epoxypropoxy) propyltrimethoxysilane/graphene (GPTMS/rGO) by adding pre-hydrolyzed FAS-17 solution in GPTMS solution, and a hybrid silane-graphene film (FG/rGO) was prepared on 2024 aluminum alloy surface. The FG/rGO film showed better thermal shock resistance, good adhesion force and high micro-hardness, compared with GPTMS/rGO film. In neutral 3.5 wt% NaCl solution, the corrosion current density for 2024 AA sample with FG/rGO film was 3.40 × 10-3 μA/cm2, which is about one fifth of that for the sample with GPTMS/rGO film. In acidic and alkaline NaCl solutions, the FG/rGO film also showed obviously better corrosion resistance than GPTMS/rGO film. EIS results confirm that the FG/rGO film showed longer performance than GPTMS/rGO film for 2024 AA in NaCl solution. The hydrophobic FAS-17 increased water contact angle of the film surface from 68° to 113°, and changed the stacking structure of graphene in the film. The higher crosslink degree and less interfaces promoted the barrier property of FG/rGO film against aggressive ions and prolonged the performance time in NaCl solution.

Characterization of zirconium alloy oxidation films by alternating current impedance

International Nuclear Information System (INIS)

Rosecrans, P.M.

1984-01-01

Kinetics of zirconium alloy oxidation are highly nonlinear. The results of electrochemical measurements and electron microscopy support the existence of porosity in oxide films formed on zirconium alloys in high temperature aqueous environments. Analytical treatment is presented relating oxidation kinetics to the thickness and distribution of nonporous elements within the oxide. This analysis illustrates that both the level and distribution of porosity within the oxide factor into oxidation kinetics. The barrier layer model can provide a basis for predicting the effect of environmental changes on oxidation rate. In addition, it demonstrates the need for further research into porosity generation mechanisms in oxide films

Characterization of zirconium alloy oxidation films by alternating current impedance

International Nuclear Information System (INIS)

Rosecrans, P.M.

1983-11-01

Kinetics of zirocnium alloy oxidation are highly nonlinear. The results of electrochemical measurements and electron microscopy support the existence of porosity in oxide films formed on zirconium alloys in high temperature aqueous environments. Analytical treatment is presented relating oxidation kinetics to the thickness and distribution of nonporous elements within the oxide. This analysis illustrates that both the level and distribution of porosity within the oxide factor into oxidation kinetics. The barrier layer model can provide a basis for predicting the effect of environmental changes on oxidation rate. In addition, it demonstrates the need for further research into porosity generation mechanisms in oxide films

Investigation on powder metallurgy Cr-Si-Ta-Al alloy target for high-resistance thin film resistors with low temperature coefficient of resistance

International Nuclear Information System (INIS)

Wang, X.Y.; Zhang, Z.S.; Bai, T.

2010-01-01

The sputtering target for high-resistance thin film resistors plays a decisive role in temperature coefficient of resistance (TCR). Silicon-rich chromium (Cr)-silicon (Si) target was designed and smelted for high-resistance thin film resistors with low TCR. Valve metal tantalum (Ta) and aluminum (Al) were introduced to the Cr-Si target to improve the performance of the target prepared. The measures for grain refining in smelting Cr-Si-Ta-Al target were taken to improve the performance of the prepared target. The mechanism and role of grain refinement were discussed in the paper. The phase structure of the prepared target was detected by X-ray diffraction (XRD). Rate of temperature drop was studied to reduce the internal stress of alloy target and conquer the easy cracking disadvantage of silicon-rich target. The electrical properties of sputtered thin film resistors were tested to evaluate the performance of the prepared target indirectly.

Soft magnetic properties of FeRuGaSi alloy films: SOFMAX

International Nuclear Information System (INIS)

Hayashi, K.; Hayakawa, M.; Ishikawa, W.; Ochiai, Y.; Iwasaki, Y.; Aso, K.

1988-01-01

To advance new soft magnetic materials of an FeGaSi alloy into the commercial world, improvements on various properties were designed by introducing additive elements without sacrificing its high saturation magnetic induction. The detailed studies on the diversified properties, such as saturation magnetic induction, film internal stress, wear resistivity, and so on, were performed. High-frequency permeability of the laminated structure film was also investigated. As a result, the Ru-added FeRuGaSi alloy films, whose typical compositions are Fe 72 Ru 4 Ga 7 Si 17 and Fe 68 Ru 8 Ga 7 Si 17 (at. %), prove to be excellent soft magnetic materials especially appropriate for the magnetic recording/playback head core use

Method of preparing an electrode material of lithium-aluminum alloy

Science.gov (United States)

Settle, Jack L.; Myles, Kevin M.; Battles, James E.

1976-01-01

A solid compact having a uniform alloy composition of lithium and aluminum is prepared as a negative electrode for an electrochemical cell. Lithium losses during preparation are minimized by dissolving aluminum within a lithium-rich melt at temperatures near the liquidus temperatures. The desired alloy composition is then solidified and fragmented. The fragments are homogenized to a uniform composition by annealing at a temperature near the solidus temperature. After comminuting to fine particles, the alloy material can be blended with powdered electrolyte and pressed into a solid compact having the desired electrode shape. In the preparation of some electrodes, an electrically conductive metal mesh is embedded into the compact as a current collector.

Synthesis of c-oriented YbBa2Cu3O7-δ films on single and polycrystalline substrates by oxidation of liquid alloys

International Nuclear Information System (INIS)

Luo, J.S.; Merchant, N.; Maroni, V.A.; Gruen, D.M.; Tani, B.S.; Sandhage, K.H.; Craven, C.A.

1991-11-01

Textured superconducting films of YbBa 2 Cu 3 O 7-δ supported on single and polycrystalline substrates were prepared by oxidation of a liquid precursor alloy. The substrates were coated by dipping them into a molten alloy (YbBa 2 Cu 3 , m.p. ∼870 degree C), withdrawing them from the melt, then oxidizing the adhering liquid alloy layer to the corresponding oxide phase, i.e., YbBa 2 Cu 3 O 7-δ . Samples prepared in this way exhibited a superconducting transition at ∼80 K following annealing in pure OP 2 at 500 degree C. With SrTiO 3 (100) and MgO (100) substrates, evidence was seen for the epitaxial growth of YbBa 2 Cu 3 O 7-δ crystals having their c-axis parallel to the [100] direction of the substrate. For polycrystalline MgO, x-ray diffraction and microstructural examination showed that the high-T c crystallites in the films were also oriented with their c-axis perpendicular to the substrate surface, but the a and b axes directions were randomly oriented rather than epitaxial

Development, preparation and characterization of uranium molybdenum alloys for dispersion fuel application

Energy Technology Data Exchange (ETDEWEB)

Sinha, V.P. [Metallic Fuels Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)], E-mail: vedsinha@barc.gov.in; Prasad, G.J.; Hegde, P.V.; Keswani, R.; Basak, C.B.; Pal, S.; Mishra, G.P. [Metallic Fuels Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

2009-04-03

Most of the research and test reactors worldwide have undergone core conversion from high enriched uranium base fuel to low enriched uranium base fuel under the Reduced Enrichment for Research and Test Reactor (RERTR) program, which was launched in the late 1970s to reduce the risk of nuclear proliferation. To realize this goal, high density uranium compounds and {gamma}-stabilized uranium alloy powder were identified. In Metallic Fuels Division of BARC, R and D efforts are on to develop these high density uranium base alloys. This paper describes the preparation flow sheet for different compositions of Uranium and molybdenum alloys by an innovative powder processing route with uranium and molybdenum metal powders as starting materials. The same composition of U-Mo alloys were also fabricated by conventional method i.e. ingot metallurgy route. The U-Mo alloys prepared by both the methods were then characterized by XRD for phase analysis. The photomicrographs of alloys with different compositions prepared by powder metallurgy and ingot metallurgy routes are also included in the paper. The paper also covers the comparison of properties of the alloys prepared by powder metallurgy and ingot metallurgy routes.

Development, preparation and characterization of uranium molybdenum alloys for dispersion fuel application

International Nuclear Information System (INIS)

Sinha, V.P.; Prasad, G.J.; Hegde, P.V.; Keswani, R.; Basak, C.B.; Pal, S.; Mishra, G.P.

2009-01-01

Most of the research and test reactors worldwide have undergone core conversion from high enriched uranium base fuel to low enriched uranium base fuel under the Reduced Enrichment for Research and Test Reactor (RERTR) program, which was launched in the late 1970s to reduce the risk of nuclear proliferation. To realize this goal, high density uranium compounds and γ-stabilized uranium alloy powder were identified. In Metallic Fuels Division of BARC, R and D efforts are on to develop these high density uranium base alloys. This paper describes the preparation flow sheet for different compositions of Uranium and molybdenum alloys by an innovative powder processing route with uranium and molybdenum metal powders as starting materials. The same composition of U-Mo alloys were also fabricated by conventional method i.e. ingot metallurgy route. The U-Mo alloys prepared by both the methods were then characterized by XRD for phase analysis. The photomicrographs of alloys with different compositions prepared by powder metallurgy and ingot metallurgy routes are also included in the paper. The paper also covers the comparison of properties of the alloys prepared by powder metallurgy and ingot metallurgy routes

Electrocatalysts with platinum, cobalt and nickel preparations by mechanical alloyed and CVD for the reaction of oxygen reduction

International Nuclear Information System (INIS)

Garcia C, M. A.

2008-01-01

In this research, the molecular oxygen reduction reaction (ORR) was investigated on electrocatalysts of Co, Ni, Pt and their alloys CoNi, PtCo, PtNi and PtCoNi by using H 2 SO 4 0.5 and KOH 0.5 M solutions as electrolytes. The electrocatalysts were synthesized by Mechanical Alloying (MA) and Chemical Vapor Deposition (CVD) processes. For MA, metallic powders were processed during 20 h of milling in a high energy SPEX 8000 mill. For CVD, a hot-wall reactor was utilized and Co, Ni and Pt acetilactetonates were used as precursors. Films were deposited at a total pressure of 1 torr and temperatures of 400-450 C. Electrocatalysts were characterized by X-Ray Diffraction (XRD). Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Energy Dispersive X-Ray Spectroscopy (EDS). Electrocatalysts prepared by mechanical alloying showed a homogeneously dispersed agglomeration of particles with nano metric size. Electrocatalysts obtained by CVD showed, in some cases, non uniform films, with particles of nano metric size, as well. The electrocatalytic performance was evaluated by using the Rotating Disk Electrode technique (RDE). Electrocatalysts prepared by MA showed higher activity than those obtained by CVD. All electrocatalysts were evaluated in alkaline media. Only electrocatalysts containing Pt were evaluated in acid media, because those materials with Co, Ni and their alloys showed instability in acidic media. Most electrocatalysts followed a mechanism for the ORR producing a certain proportion of H 2 O 2 . All electrocatalysts, exhibited a fair or good electrocatalytic activity in comparison with other similar reported materials. It was found that MA and CVD are appropriate processes to prepare electrocatalysts for the ORR with particles of nano metric size and performing with an acceptable catalytic activity. PtCoNi 70-23-7% by MA and PtCoNi-CVD electrocatalysts showed the highest activity in alkaline media, while in acidic electrolyte PtCoNi 70

Gilbert damping constant of FePd alloy thin films estimated by broadband ferromagnetic resonance

Directory of Open Access Journals (Sweden)

Kawai T.

2014-07-01

Full Text Available Magnetic relaxation of FePd alloy epitaxial thin films with very flat surfaces prepared on MgO(001 substrate are measured by in-plane broadband ferromagnetic resonance (FMR. Magnetic relaxation is investigated as Δω for FMR absorption peak by frequency sweep measurements. ΔH is calculated by using the measured Δω. Gilbert damping constant, α, is estimated by employing a straight line fitting of the resonant frequency dependence of ΔH. The α value for an FePd film deposited at 200 ˚C, which shows disordered A1 structure, is 0.010 and ΔH0, which is frequency independent part of ΔH, is 10 Oe. The α value for a film annealed at 400 ˚C, which shows partially L10 ordered structure (S=0.32, is 0.013, which is slightly larger than that for the disorder A1 structure film. However, ΔH0 for the annealed film is 85 Oe, which is much larger than that for the film with disordered structure. The results show that the magnetic relaxation of the 400 ˚C annealed film is mainly dominated by ΔH0, which is related with magnetic in-homogeneity caused by the appearance of perpendicular anisotropy of partially ordered phase.

Structure and superconducting properties of Nb-Zr alloy films made by a high-rate sputtering

International Nuclear Information System (INIS)

Sekine, Hisashi; Inoue, Kiyoshi; Tachikawa, Kyoji

1978-01-01

Superconducting Nb-Zr alloy films have been prepared by a continuous high-rate sputtering on tantalum substrates. A deposition rate of 330 nm/min has been attained. The compositional profile in the Nb-Zr film is quite uniform and the film has nearly the same composition as that of the target. The films deposited in a pure argon atmosphere show a columnar structure grown perpendicular to the substrate. The grain size strongly depends on the substrate temperature. The phase transformations in the Nb-Zr film become more apparent and the structure becomes closer to the equilibrium state as the film is deposited in higher atmosphere pressures and/or at lower target voltages. The superconducting transition temperature T sub(c) of the films is about the same as that of bulk samples. The dependence of T sub(c) on the substrate temperature is explainable on the phase transformations in the film. Critical current density J sub(c) and its anisotropy is closely related to the grain structure of the film. Grain boundaries seem to act as the most predominant flux pinning centers in the films. Effects of oxygen in the sputtering atmosphere on the structure and superconducting properties of the Nb-Zr films have been also investigated. Oxygen significantly decreases the grain size of the film. Oxygen increases J sub(c) but decreases T sub(c) of the film. (auth.)

Thermally stimulated current analysis of Zn{sub 1-x}Cd{sub x}O alloy films

Energy Technology Data Exchange (ETDEWEB)

Aybek, A. Senol, E-mail: saybek@anadolu.edu.tr [Department of Physics, Anadolu University, Eskisehir 26470 (Turkey); Baysal, Nihal [Kilicoglu Anadolu High School, Eskisehir 26050 (Turkey); Zor, Muhsin; Turan, Evren; Kul, Metin [Department of Physics, Anadolu University, Eskisehir 26470 (Turkey)

2011-02-03

Research highlights: > We have studied the structural and electrical properties of Zn{sub 1-x}Cd{sub x}O alloy films deposited by ultrasonic spray pyrolysis technique. > The trap energy, the capture cross-section, the attempt-to-escape frequency and the concentration of the traps in Zn{sub 1-x}Cd{sub x}O films are reported. > The effect of the Cd incorporation into ZnO material on trapping levels was investigated by the TSC measurements. Two overlapped peaks were registered at levels of 0.033 and 0.197 eV in ZnO sample by the curve fitting technique. The observed trap energy levels for ZnO film is thought to originate from zinc interstitials and oxygen vacancies. However, the incorporation of Cd into Zn{sub 1-x}Cd{sub x}O alloy films with x = 0.59 have resulted in two trapping centers with activation energies of 0.118 and 0.215 eV. The observed trap levels in Zn{sub 0.41}Cd{sub 0.59}O alloy film are related to oxygen adsorption in the sample. - Abstract: We have studied the structural and electrical properties of Zn{sub 1-x}Cd{sub x}O alloy films deposited by ultrasonic spray pyrolysis technique. XRD measurement indicated that pure ZnO and CdO samples had single phases with hexagonal wurtzite and cubic structures, respectively. However, Zn{sub 1-x}Cd{sub x}O alloy films with x = 0.59 and 0.78 exhibited mixtures of a hexagonal wurtzite ZnO phase and a cubic CdO phase. Analysis of thermally stimulated current spectra of Zn{sub 1-x}Cd{sub x}O alloy films revealed the existence of a number of overlapped peaks each characterized by different trap energy levels located in the range of 0.033-0.215 eV below the conduction band. We have used curve fitting method for the evaluation of the trap parameters of the alloy films. The values of attempt-to-escape frequency {nu}, capture cross-section S and concentration of the traps N{sub t} have been determined.

Metallurgically prepared NiCu alloys as cathode materials for hydrogen evolution reaction

International Nuclear Information System (INIS)

Wang, Kunchan; Xia, Ming; Xiao, Tao; Lei, Ting; Yan, Weishan

2017-01-01

Ni−Cu bimetallic alloys with Cu content of 5, 10, 20, 30 and 50 wt% are prepared by powder metallurgy method, which consisted of powder mixing, pressing and sintering processes. The X-ray diffraction (XRD) measurement confirms that all the five Ni−Cu alloys possess the f.c.c. structure. The hydrogen evolution reaction (HER) activity of the prepared Ni−Cu alloy electrodes was studied in 6 M KOH solution by cathodic current-potential curves and electrochemical impedance spectroscopy (EIS) techniques. It was found that the electrocatalytic activity for the HER depended on the composition of Ni−Cu alloys, where Ni−10Cu alloy exhibited considerably higher HER activity than Ni plate and other Ni−Cu alloys, indicative of its chemical composition related intrinsic activity. - Highlights: • Ni−Cu alloys with various Cu contents were prepared by powder metallurgy method. • Ni−Cu alloy exhibits chemical composition related synergistic effect for HER activity. • Ni−10Cu alloy electrode presents a most efficient activity for HER. • Two time constants are observed in Nyquist curve and both of them related to the kinetics of HER.

Metallurgically prepared NiCu alloys as cathode materials for hydrogen evolution reaction

Energy Technology Data Exchange (ETDEWEB)

Wang, Kunchan; Xia, Ming [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); Xiao, Tao [2nd Xiangya Hospital, Central South University, Changsha 410011 (China); Lei, Ting, E-mail: tlei@mail.csu.edu.cn [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); Yan, Weishan [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China)

2017-01-15

Ni−Cu bimetallic alloys with Cu content of 5, 10, 20, 30 and 50 wt% are prepared by powder metallurgy method, which consisted of powder mixing, pressing and sintering processes. The X-ray diffraction (XRD) measurement confirms that all the five Ni−Cu alloys possess the f.c.c. structure. The hydrogen evolution reaction (HER) activity of the prepared Ni−Cu alloy electrodes was studied in 6 M KOH solution by cathodic current-potential curves and electrochemical impedance spectroscopy (EIS) techniques. It was found that the electrocatalytic activity for the HER depended on the composition of Ni−Cu alloys, where Ni−10Cu alloy exhibited considerably higher HER activity than Ni plate and other Ni−Cu alloys, indicative of its chemical composition related intrinsic activity. - Highlights: • Ni−Cu alloys with various Cu contents were prepared by powder metallurgy method. • Ni−Cu alloy exhibits chemical composition related synergistic effect for HER activity. • Ni−10Cu alloy electrode presents a most efficient activity for HER. • Two time constants are observed in Nyquist curve and both of them related to the kinetics of HER.

Preparation, characterization and wear behavior of carbon coated magnesium alloy with electroless plating nickel interlayer

International Nuclear Information System (INIS)

Mao, Yan; Li, Zhuguo; Feng, Kai; Guo, Xingwu; Zhou, Zhifeng; Dong, Jie; Wu, Yixiong

2015-01-01

Highlights: • The carbon film with nickel interlayer (Ni + C coating) is deposited on GW83. • In Ni + C composite coating the carbon coating has good adhesion with the nickel interlayer. • The wear track of Ni + C coating is narrower compared to the bare one. • The wear resistance of GW83 is greatly improved by the Ni + C coating. - Abstract: Poor wear resistance of rare earth magnesium alloys has prevented them from wider application. In this study, composite coating (PVD carbon coating deposited on electroless plating nickel interlayer) is prepared to protect GW83 magnesium alloys against wear. The Ni + C composite coating has a dense microstructure, improved adhesion strength and hardness due to the effective support of Ni interlayer. The wear test result shows that the Ni + C composite coating can greatly prolong the wear life of the magnesium alloy. The wear track of the Ni + C coated magnesium alloy is obviously narrower and shows less abrasive particles as compared with the bare one. Abrasive wear is the wear mechanism of the coatings at the room temperature. In conclusion, the wear resistance of the GW83 magnesium alloy can be greatly improved by the Ni + C composite coating

Low-Power Super-resolution Readout with Antimony Bismuth Alloy Film as Mask layer

International Nuclear Information System (INIS)

Lai-Xin, Jiang; Yi-Qun, Wu; Yang, Wang; Jing-Song, Wei; Fu-Xi, Gan

2009-01-01

Sb–Bi alloy films are proposed as a new kind of super-resolution mask layer with low readout threshold power. Using the Sb–Bi alloy film as a mask layer and SiN as a protective layer in a read-only memory disc, the super-resolution pits with diameters of 380 nm are read out by a dynamic setup, the laser wavelength is 780 nm and the numerical aperture of pickup lens is 0.45. The effects of the Sb–Bi thin film thickness, laser readout power and disc rotating velocity on the readout signal are investigated. The results show that the threshold laser power of super-resolution readout of the Sb–Bi mask layer is about 0.5 mW, and the corresponding carrier-to-noise ratio is about 20 dB at the film thickness of 50 nm. The super-resolution mechanism of the Sb–Bi alloy mask layer is discussed based on its temperature dependence of reflection

Preparation technology of 103Pd-110Agm composite alloy membranes

International Nuclear Information System (INIS)

Liu Zhuo; Chen Daming; Jin Xiaohai; Li Zhongyong; Guo Feihu; Qin Hongbin

2012-01-01

The preparation of 103 Pd- 110 Ag m alloy membranes was the basis for the production of 103 Pd- 125 I composite sources. Taking 103 Pd and 110 Ag m as trace elements, the method of non-electrolytical plating was chosen to prepare the alloy membrane. A γ-detector and electron microscope (SEM) were used for quantitative and qualitative analysis, respectively. The pre-treatment of the support before the preparation of Palladium-silver composite membranes was discussed in detail. It was found that when the concentration of PdCl 2 was between 0.5 and 2.0 mmol/L the result was good. The effects of various factors were investigated, including the proportion of Pd and Ag, the concentrations of the total metal, ammonium hydroxide hydrazine and ethylenediaminetetraacetic acid, temperature, the time, and the rotation speed. By improving the reaction conditions the alloy membrane with metallic luster was obtained. Besides, the presence of Pd and Ag was observed in the alloy membranes by qualitative analysis. (authors)

Influence of multiple reflection and optical interference on the magneto-optical properties of Co-Pt alloy films investigated by using the characteristic matrix method

International Nuclear Information System (INIS)

Zou, Z. Q.; Lee, Y. P.; Kim, K. W.

2000-01-01

The magneto-optical Kerr effect (MOKE) of a multilayered system was described by using the characteristic matrix method based on the electromagnetic wave theory. In addition to the multiple reflection and the optical interference, a contribution from the plasma resonance absorption of a metallic layer can be included in the formulation. As an example, we carried out a simulation of the MOKE for Co 0.25 Pt 0.75 alloy films with and without a Pt buffer layer. It was found that the Kerr rotation and the read-out figure of merit of a film directly deposited on a glass substrate were enhanced at a thickness below 40 nm owing to the multiple reflection and the optical interference. This enhancement was more remakable at long wavelengths when light was incident on the substrate side. However, the introduction of a Pt buffer layer was not beneficial in improving the Kerr rotation and the figure of merit, although it promoted the perpendicular magnetic anisotropy of the film, as reported. The simulated results for an alloy thickness beyond the penetration depth of light agreed well with the experimental data for a prepared 'thick' alloy film

Laser deposition rates of thin films of selected metals and alloys

DEFF Research Database (Denmark)

Cazzaniga, Andrea Carlo; Canulescu, Stela; Schou, Jørgen

Thin films of Cu, Zn and Sn as well as mixtures of these elements have been produced by Pulsed Laser Deposition (PLD). The deposition rate of single and multicomponent metallic targets was determined. The strength of PLD is that the stoichiometry of complex compounds, even of complicated alloys...... or metal oxides, can be preserved from target to film. We apply this technique to design films of a mixture of Cu, Zn and Sn, which are constituents of the chalcogenide CZTS, which has a composition close to Cu2ZnSnS4. This compound is expected to be an important candidate for absorbers in new solar cells...... for alloys of the different elements as well as compounds with S will be presented....

Robust tribo-mechanical and hot corrosion resistance of ultra-refractory Ta-Hf-C ternary alloy films.

Science.gov (United States)

Yate, Luis; Coy, L Emerson; Aperador, Willian

2017-06-08

In this work we report the hot corrosion properties of binary and ternary films of the Ta-Hf-C system in V 2 O 5 -Na 2 SO 4 (50%wt.-50%wt.) molten salts at 700 °C deposited on AISI D3 steel substrates. Additionally, the mechanical and nanowear properties of the films were studied. The results show that the ternary alloys consist of solid solutions of the TaC and HfC binary carbides. The ternary alloy films have higher hardness and elastic recoveries, reaching 26.2 GPa and 87%, respectively, and lower nanowear when compared to the binary films. The corrosion rates of the ternary alloys have a superior behavior compared to the binary films, with corrosion rates as low as 0.058 μm/year. The combination and tunability of high hardness, elastic recovery, low nanowear and an excellent resistance to high temperature corrosion demonstrates the potential of the ternary Ta-Hf-C alloy films for applications in extreme conditions.

Energy barriers in nanometer sized magnetic islands prepared from alloyed and multilayered Co/Pt films

NARCIS (Netherlands)

Abelmann, Leon; de Vries, Jeroen; Bolhuis, Thijs; Kikuchi, Nobuaki

2014-01-01

By means of Anomalous Hall Effect measurements, we investigated the thermal switching field distribution of individual magnetic thin film circular elements with out-of-plane easy axis in a temperature range from 10K to 300K. We compared this behavior for elements prepared from either Co80Pt20

Microstructure and mechanical properties of diamond films on titanium-aluminum-vanadium alloy

Science.gov (United States)

Catledge, Shane Aaron

The primary focus of this dissertation is the investigation of the processing-structure-property relationships of diamond films deposited on Ti-6Al-4V alloy by microwave plasma chemical vapor deposition (MPCVD). By depositing a well-adhered protective layer of diamond on an alloy component, its hardness, wear-resistance, performance, and overall lifetime could be significantly increased. However, due to the large thermal expansion mismatch between the diamond film and metal (and the corresponding residual stress induced in the film), film adhesion is typically unsatisfactory and often results in immediate delamination after processing. Therefore, it is a major goal of this research to improve adhesion of the diamond film to the alloy substrate. Through the use of innovative processing techniques involving MPCVD deposition conditions and methane (CH4), nitrogen (N2), and hydrogen (H2) chemistry, we have achieved diamond films which consistently adhere to the alloy substrate. In addition, we have discovered that, with the appropriate choice of deposition conditions, the film structure can be tailored to range from highly crystalline, well-faceted diamond to nanocrystalline diamond with extremely low surface roughness (as low as 27 nm). The relationship between processing and structure was studied using in-situ optical emission spectroscopy, micro-Raman spectroscopy, surface profilometry, glancing-angle x-ray diffraction, and scanning electron microscopy. We observe that when nitrogen is added to the H2/CH4 feedgas mixture, a carbon-nitrogen (CN) emission band arises and its relative abundance to the carbon dimer (C2) gas species is shown to have a pronounced influence on the diamond film structure. By appropriate choice of deposition chemistry and conditions, we can tailor the diamond film structure and its corresponding properties. The mechanical properties of interest in this thesis are those relating to the integrity of the film/substrate interface, as well as the

Improved performance of Mg–Y alloy thin film switchable mirrors after coating with a superhydrophobic surface

International Nuclear Information System (INIS)

La, Mao; Zhou, Huaijuan; Li, Ning; Xin, Yunchuan; Sha, Ren; Bao, Shanhu; Jin, Ping

2017-01-01

Highlights: • The PTFE films was prepared for use as the top layer of Mg–Y/Pd switchable mirrors. • The PTFE as an antireflection layer to improve the luminous transmission, and also to enhance the switching durability of the switchable mirrors. • The PTFE film has a superhydrophobic surface, which endows the Mg–Y/Pd switchable mirrors with self-cleaning properties. - Abstract: The magnesium based switchable mirrors can reversibly change their optical properties between the transparent and the reflective state as a result of hydrogenation and dehydrogenation. These films can potentially be applied as new energy-saving windows, by controlling the transmittance of solar radiation through the regulation of their reflective state. In this study, magnesium–yttrium (Mg–Y) alloy thin films were prepared using a DC magnetron sputtering method. However, the luminous transmittance in the transparent state and the switching durability of switchable mirrors are too poor to satisfy practical demands. In order to improve the films switching durability, luminous transmittance and the surface functionalization, polytetrafluoroethylene (PTFE) was coated with thermal vacuum deposition for use as the top layer of Mg–Y/Pd switchable mirrors. The PTFE layer had a porous network structure and exhibited a superhydrophobic surface with a water contact angle of approximately 152°. By characterization, PTFE thin films shows the excellent protection role against the oxidization of Mg, the switching durability of the films were improved 3 times, and also shows the antireflection role the luminous transmission of films was enhanced by 7% through the top covered with PTFE.

Improved performance of Mg–Y alloy thin film switchable mirrors after coating with a superhydrophobic surface

Energy Technology Data Exchange (ETDEWEB)

La, Mao [Department of Chemistry and Environmental Science, Inner Mongolia Normal University, Hohhot, Inner Mongolia, 010020 (China); State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, 200050 (China); Zhou, Huaijuan; Li, Ning; Xin, Yunchuan [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, 200050 (China); Sha, Ren, E-mail: sr@imnu.edu.cn [Department of Chemistry and Environmental Science, Inner Mongolia Normal University, Hohhot, Inner Mongolia, 010020 (China); Bao, Shanhu, E-mail: shanhu.bao@mail.sic.ac.cn [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, 200050 (China); Jin, Ping [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, 200050 (China)

2017-05-01

Highlights: • The PTFE films was prepared for use as the top layer of Mg–Y/Pd switchable mirrors. • The PTFE as an antireflection layer to improve the luminous transmission, and also to enhance the switching durability of the switchable mirrors. • The PTFE film has a superhydrophobic surface, which endows the Mg–Y/Pd switchable mirrors with self-cleaning properties. - Abstract: The magnesium based switchable mirrors can reversibly change their optical properties between the transparent and the reflective state as a result of hydrogenation and dehydrogenation. These films can potentially be applied as new energy-saving windows, by controlling the transmittance of solar radiation through the regulation of their reflective state. In this study, magnesium–yttrium (Mg–Y) alloy thin films were prepared using a DC magnetron sputtering method. However, the luminous transmittance in the transparent state and the switching durability of switchable mirrors are too poor to satisfy practical demands. In order to improve the films switching durability, luminous transmittance and the surface functionalization, polytetrafluoroethylene (PTFE) was coated with thermal vacuum deposition for use as the top layer of Mg–Y/Pd switchable mirrors. The PTFE layer had a porous network structure and exhibited a superhydrophobic surface with a water contact angle of approximately 152°. By characterization, PTFE thin films shows the excellent protection role against the oxidization of Mg, the switching durability of the films were improved 3 times, and also shows the antireflection role the luminous transmission of films was enhanced by 7% through the top covered with PTFE.

Titanium-silicon films prepared by spin and dip-coating

International Nuclear Information System (INIS)

Nassar, Eduardo J.; Ciuffi, Katia J.; Goncalves, Rogeria R.; Messaddeq, Younes; Ribeiro, Sidney J.L.

2003-01-01

The conditions for the preparation of luminescent materials, consisting of Eu 3+ ions entrapped in a titanium matrix, in the form of a thin film, using the sol-gel process, are described. The films were obtained from sols prepared with TEOS and TEOT, in the presence of acetylacetone as the hydrolysis-retarding agent, using the dip-coating and spin-coating techniques. The influence of these techniques on the films based on titanium and silicon are presented. The Eu 3+ was used as a luminescent probe. The films have been characterized by luminescence, reflection and transmittance. The thickness of the films could be related to the preparation procedure. Transparent thin films have been prepared by dip-coating technique. (author)

Experimental study of the oxide film structural phase state in the E635 and E110 alloys

International Nuclear Information System (INIS)

Shevyakov, A. Yu.; Shishov, V. N.; Novikov, V. V.

2013-01-01

The microstructure, phase and element compositions of oxide films of E110 (Zr-1%Nb) and E635 (Zr-1%Nb-0,35%Fe-1,2%Sn) alloys after autoclave tests in pure water had been studied by the method of transmission electron microscopy (TEM) with energy dispersive X-ray spectroscopy (EDS). TEM investigations of oxide film structure were carried on different oxide layers according to their thickness (near interface of “metal-oxide”, in central part of the oxide film and near outer surface) and in cross-section. The results of the tests show that oxide films of the alloys have different microstructure (grain size, fraction of tetragonal phase, content of defects, etc) and the phase compositions. The crystal structure of oxide films is mainly monoclinic, however, at the “metal-oxide” interface there are a significant fraction of the tetragonal phase. Researching of oxides on different stages of oxidation allow us to determine the kinetics of the second phase precipitate structure change: a) in E635 alloy at early oxidation stages of the amorphization process of the Laves phase precipitates begins with decreasing the content of iron and niobium; b) in E110 alloy the amorphization process of β-Nb precipitates begins at a later stage of oxidation. The influence of changes of the crystal structure and the chemical composition of the second phase precipitates on protective properties of the oxides had been determined. Researching of alloying element redistribution in E635 alloy oxide film shows that iron and niobium are concentrated in pores. Increased porosity of the E635 alloy oxide films at a later oxidation stage, in comparison with the E110 alloy, shows the influence of change composition and subsequent dissolution of the Laves phase particles on the pore formation in the oxide. (authors)

The Characterization of Thin Film Nickel Titanium Shape Memory Alloys

Science.gov (United States)

Harris Odum, Nicole Latrice

Shape memory alloys (SMA) are able to recover their original shape through the appropriate heat or stress exposure after enduring mechanical deformation at a low temperature. Numerous alloy systems have been discovered which produce this unique feature like TiNb, AgCd, NiAl, NiTi, and CuZnAl. Since their discovery, bulk scale SMAs have undergone extensive material property investigations and are employed in real world applications. However, its thin film counterparts have been modestly investigated and applied. Researchers have introduced numerous theoretical microelectromechanical system (MEMS) devices; yet, the research community's overall unfamiliarity with the thin film properties has delayed growth in this area. In addition, it has been difficult to outline efficient thin film processing techniques. In this dissertation, NiTi thin film processing and characterization techniques will be outlined and discussed. NiTi thin films---1 mum thick---were produced using sputter deposition techniques. Substrate bound thin films were deposited to analysis the surface using Scanning Electron Microscopy; the film composition was obtained using Energy Dispersive Spectroscopy; the phases were identified using X-ray diffraction; and the transformation temperatures acquired using resistivity testing. Microfabrication processing and sputter deposition were employed to develop tensile membranes for membrane deflection experimentation to gain insight on the mechanical properties of the thin films. The incorporation of these findings will aid in the movement of SMA microactuation devices from theory to fruition and greatly benefit industries such as medicinal and aeronautical.

Corrosion-resistant amorphous metallic films of Mo49Cr33B18 alloy

Science.gov (United States)

Ramesham, R.; Distefano, S.; Fitzgerald, D.; Thakoor, A. P.; Khanna, S. K.

1987-01-01

Corrosion-resistant amorphous metallic alloy films of Mo49Cr33B18 with a crystallization temperature of 590 C were deposited onto glass and quartz substrates by magnetron sputter-quench technique. The amorphous nature of the films was confirmed by their diffuse X-ray diffraction patterns. The deposited films are densely packed (zone T) and exhibit low stress and good adhesion to the substrate. Corrosion current of as-deposited coating of MoCrB amorphous metallic alloy is approximately three orders of magnitude less than the corrosion current of 304 stainless steel in 1N H2SO4 solution.

Electrochemical preparation of poly(methylene blue)/graphene nanocomposite thin films

International Nuclear Information System (INIS)

Erçarıkcı, Elif; Dağcı, Kader; Topçu, Ezgi; Alanyalıoğlu, Murat

2014-01-01

Highlights: • Poly(MB)/graphene thin films are prepared by a simple electrochemical approach. • Graphene layers in the film show a broad band in visible region of absorbance spectra. • Morphology of composite films indicates both disordered and ordered regions. • XRD reveals that nanocomposite films include rGO layers after electropolymerization process. • Chemically prepared graphene is better than electrochemically prepared graphene for electrooxidation of nitrite. - Abstract: Poly(methylene blue)/graphene nanocomposite thin films were prepared by electropolymerization of methylene blue in the presence of graphene which have been synthesized by two different methods of a chemical oxidation process and an electrochemical approach. Synthesized nanocomposite thin films were characterized by using cyclic voltammetry, UV–vis. absorption spectroscopy, powder X-ray diffraction, and scanning tunneling microscopy techniques. Electrocatalytical properties of prepared poly(methylene blue)/graphene nanocomposite films were compared toward electrochemical oxidation of nitrite. Under optimized conditions, electrocatalytical effect of nanocomposite films of chemically prepared graphene through electrochemical oxidation of nitrite was better than that of electrochemically prepared graphene

Highly-enhanced reflow characteristics of sputter deposited Cu alloy thin films for large scale integrated interconnections

Energy Technology Data Exchange (ETDEWEB)

Onishi, Takashi [Advanced Technology Information Center, Shinko Research Co., Ltd., 2-7, 4-Chome, Iwaya-Nakamachi, Nada-ku, Kobe 657-0845 (Japan); Mizuno, Masao [Technical Development Group, Electronics Research Laboratory, Kobe Steel, Ltd., 5-5, Takatsukadai 1-chome, Nishi-ku, Kobe 651-2271 (Japan); Yoshikawa, Tetsuya; Munemasa, Jun [Machinery and Engineering Company, Kobe Steel, Ltd., 2-3-1, Shinhama, Arai-cho, Takasago 676-8670 (Japan); Mizuno, Masataka; Kihara, Teruo; Araki, Hideki [Division of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, 2-1, Yamadaoka, Suita 565-0871 (Japan); Shirai, Yasuharu [Department of Materials Science and Engineering, Graduate School of Engineering, Kyoto University, Yoshida-Honmachi, Sakyo-ku, Kyoto 606-8501 (Japan)

2011-08-01

An attempt to improve the reflow characteristics of sputtered Cu films was made by alloying the Cu with various elements. We selected Y, Sb, Nd, Sm, Gd, Dy, In, Sn, Mg, and P for the alloys, and ''the elasto-plastic deformation behavior at high temperature'' and ''the filling level of Cu into via holes'' were estimated for Cu films containing each of these elements. From the results, it was found that adding a small amount of Sb or Dy to the sputtered Cu was remarkably effective in improve the reflow characteristics. The microstructure and imperfections in the Cu films before and after high-temperature high-pressure annealing were investigated by secondary ion micrographs and positron annihilation spectroscopy. The results imply that the embedding or deformation mechanism is different for the Cu-Sb alloy films compared to the Cu-Dy alloy films. We consider that the former is embedded by softening or deformation of the Cu matrix, which has a polycrystalline structure, and the latter is embedded by grain boundary sliding.

Preparation of rare earth-cobalt magnet alloy by reduction-diffusion process

International Nuclear Information System (INIS)

Krishnan, T.S.

1980-01-01

Preparation of rare earth-cobalt alloys by reduction-diffusion (R-D) process is described. The process essentially involves mixing of the rare earth oxide and cobalt/cobalt oxide powders in proper proportion and high temperature reduction of the charge in hydrogen atmosphere, followed by aqueous leaching of the reduced mass to yield the alloy powder. Comparison is made of the magnetic properties of the R-D powder with those of the powder prepared by the direct melting (DM) route and it is observed from the reported values for SmCo 5 that the energy product of the R-D powder (approximately 22 MGOe) is only marginally lower than that of the directly melted alloy (approximately 25 MGOe). The paper also includes the results of studies carried out at the Bhabha Atomic Research Centre, Bombay, on the preparation of misch metal-cobalt alloy by the R-D process. (auth.)

The Microstructures and Electrical Resistivity of (Al, Cr, TiFeCoNiOx High-Entropy Alloy Oxide Thin Films

Directory of Open Access Journals (Sweden)

Chun-Huei Tsau

2015-01-01

Full Text Available The (Al, Cr, TiFeCoNi alloy thin films were deposited by PVD and using the equimolar targets with same compositions from the concept of high-entropy alloys. The thin films became metal oxide films after annealing at vacuum furnace for a period; and the resistivity of these thin films decreased sharply. After optimum annealing treatment, the lowest resistivity of the FeCoNiOx, CrFeCoNiOx, AlFeCoNiOx, and TiFeCoNiOx films was 22, 42, 18, and 35 μΩ-cm, respectively. This value is close to that of most of the metallic alloys. This phenomenon was caused by delaminating of the alloy oxide thin films because the oxidation was from the surfaces of the thin films. The low resistivity of these oxide films was contributed to the nonfully oxidized elements in the bottom layers and also vanishing of the defects during annealing.

Thin film shape memory alloys for optical sensing applications

International Nuclear Information System (INIS)

Fu, Y Q; Luo, J K; Huang, W M; Flewitt, A J; Milne, W I

2007-01-01

Based on shape memory effect of the sputtered thin film shape memory alloys, different types of micromirror structures were designed and fabricated for optical sensing application. Using surface micromachining, TiNi membrane mirror structure has been fabricated, which can be actuated based on intrinsic two-way shape memory effect of the free-standing TiNi film. Using bulk micromachining, TiNi/Si and TiNi/Si 3 N 4 microcantilever mirror structures were fabricated

Preparing rare earth-silicon-iron-aluminum alloys

International Nuclear Information System (INIS)

Marchant, J.D.; Morrice, E.; Herve, B.P.; Wong, M.M.

1980-01-01

As part of its mission to assure the maximum recovery and use of the Nation's mineral resources, the Bureau of Mines, investigated an improved procedure for producing rare earth-silicon alloys. For example, a charge consisting of 681 grams of mixed rare-earth oxides, 309 grams of ferrosilicon (75 wt-pct Si), and 182 grams of aluminum metal along with a flux consisting of 681 grams of CaO and 45 grams of MgO was reacted at 1500 0 C in an induction furnace. Good slag-metal separation was achieved. The alloy product contained, in weight-percent, 53 RE, 28 Si, 11 Fe, and 4 Al with a rare earth recovery of 80 pct. In current industrial practice rare earth recoveries are usually about 60 pct in alloy products that contain approximately 30 wt-pct each of rare earths and silicon. Metallurgical evaluations showed the alloys prepared in this investigation to be as effective in controlling the detrimental effect of sulfur in steel and cast iron as the commercial rare earth-silicon-iron alloys presently used in the steel industry

Copper-Silver Alloy Depositions Using Thermionic Vacuum ARC (TVA)

International Nuclear Information System (INIS)

Akan, T.

2004-01-01

TVA is a plasma source generating pure metal vapor plasma and consists of a heated cathode emitting thermo electrons and an anode containing material to be evaporated. We used Cu and Ag pieces as anode materials and produced their alloys by electron bombarding. Cu-Ag alloys in various mass ratios were prepared by using the TVA and the TVA discharges were generated in the vapors of these alloys. The volt-ampere characteristics of the TVA discharges generated in the vapors of these alloys were investigated with respect to the ratio of Ag in the Cu-Ag alloy. Cu-Ag alloy thin films with various mass ratios were deposited onto the glass substrates by using their TVA discharges. The ratios of Cu and Ag in the thin Cu-Ag alloy films were found using scanning electron microscope-energy dispersive xray (SEM-EDX) microanalyses

Crystallization and growth of Ni-Si alloy thin films on inert and on silicon substrates

Science.gov (United States)

Grimberg, I.; Weiss, B. Z.

1995-04-01

The crystallization kinetics and thermal stability of NiSi2±0.2 alloy thin films coevaporated on two different substrates were studied. The substrates were: silicon single crystal [Si(100)] and thermally oxidized silicon single crystal. In situ resistance measurements, transmission electron microscopy, x-ray diffraction, Auger electron spectroscopy, and Rutherford backscattering spectroscopy were used. The postdeposition microstructure consisted of a mixture of amorphous and crystalline phases. The amorphous phase, independent of the composition, crystallizes homogeneously to NiSi2 at temperatures lower than 200 °C. The activation energy, determined in the range of 1.4-2.54 eV, depends on the type of the substrate and on the composition of the alloyed films. The activation energy for the alloys deposited on the inert substrate was found to be lower than for the alloys deposited on silicon single crystal. The lowest activation energy was obtained for nonstoichiometric NiSi2.2, the highest for NiSi2—on both substrates. The crystallization mode depends on the structure of the as-deposited films, especially the density of the existing crystalline nuclei. Substantial differences were observed in the thermal stability of the NiSi2 compound on both substrates. With the alloy films deposited on the Si substrate, only the NiSi2 phase was identified after annealing to temperatures up to 800 °C. In the films deposited on the inert substrate, NiSi and NiSi2 phases were identified when the Ni content in the alloy exceeded 33 at. %. The effects of composition and the type of substrate on the crystallization kinetics and thermal stability are discussed.

Powder-metallurgy preparation of NiTi shape-memory alloy using mechanical alloying and spark-plasma sintering.

Czech Academy of Sciences Publication Activity Database

Novák, P.; Moravec, H.; Vojtěch, V.; Knaislová, A.; Školáková, A.; Kubatík, Tomáš František; Kopeček, Jaromír

2017-01-01

Roč. 51, č. 1 (2017), s. 141-144 ISSN 1580-2949 R&D Projects: GA ČR(CZ) GA14-03044S Institutional support: RVO:61389021 ; RVO:68378271 Keywords : mechanical alloying * spark plasma sintering * NiTi * shape memory alloy Subject RIV: JG - Metallurgy; JG - Metallurgy (FZU-D) OBOR OECD: Materials engineering ; Materials engineering (FZU-D) Impact factor: 0.436, year: 2016 https://www.researchgate.net/publication/313900224_Powder-metallurgy_preparation_of_NiTi_shape-memory_alloy_using_mechanical_alloying_and_spark-plasma_sintering

In-situ XRD study of alloyed Cu2ZnSnSe4-CuInSe2 thin films for solar cells

International Nuclear Information System (INIS)

Hartnauer, Stefan; Wägele, Leonard A.; Jarzembowski, Enrico; Scheer, Roland

2015-01-01

We investigate the growth of Cu 2 ZnSnSe 4 -CuInSe 2 (CZTISe) thin films using a 2-stage (Cu-rich/Cu-free) co-evaporation process under simultaneous application of in-situ angle dispersive X-ray diffraction (XRD). In-situ XRD allows monitoring the phase formation during preparation. A variation of the content of indium in CZTISe leads to a change in the lattice constant. Single phase CZTISe is formed in a wide range, while at high In contents a phase separation is detected. Because of different thermal expansion coefficients, the X-ray diffraction peaks of ZnSe and CZTISe can be distinguished at elevated substrate temperatures. The formation of ZnSe appears to be inhibited even for low indium content. In-situ XRD shows no detectable sign for the formation of ZnSe. First solar cells of CZTISe have been prepared and show comparable performance to CZTSe. - Highlights: • In-situ XRD study of two-stage co-evaporated Cu 2 ZnSnSe 4 -CuInSe 2 alloyed thin films. • No detection of ZnSe with in-situ XRD due to Indium incorporation • Comparable efficiency of alloyed solar cells

Influence of pH on the chemical and structural properties of the oxide films formed on 316L stainless steel, alloy 600 and alloy 690 in high temperature aqueous environments

International Nuclear Information System (INIS)

Dupin, M.; Gosser, P.; Walls, M.G.; Rondot, B.; Pastol, J.L.

2002-01-01

The oxide films formed on 316L stainless steel, alloy 600 and alloy 690 at 320 deg C in high temperature aqueous environments of different pH have been examined by glow discharge optical spectroscopy, scanning electron microscopy, atomic force microscopy and capacitance measurements. The analytical study reveals that the films formed at pH 5 are mainly composed of chromium oxides. When the pH increases the chromium concentration decreases and those of the other two elements (Ni and Fe) tend to increase. The films formed at pH 5 on 316L stainless steel and alloy 600 are thick and powder-like. The film formed at the same pH on alloy 690 is thin and is composed of a compact protective inner layer and a less-compact outer layer formed by crystals of mixed iron-nickel-chromium oxides. The morphological appearance of the thick films and that of the thin films is very different. However, equivalent morphologies can be observed for the relatively thin duplex films formed at pH 8 and pH 9.5 on the 316L stainless steel and nickel-base alloys. The evolution of the chemical composition of the films is accompanied by important changes from the point of view of their semi-conductivity. (authors)

Preparation and Properties of EPDM/Silicone Alloy Using Maleated EPDM-polydimethylsiloxane Compatibilizer

Energy Technology Data Exchange (ETDEWEB)

Kang, Doo Whan; Kim, Bum Jin [Hyperstructured Organic Materials Research Center, Department of Polymer Science and Engineering, Dankook University, Seoul (Korea); Shim, Dae Sup [Korea Electrotechnology Research Institute, Euiwang (Korea)

2001-05-01

EPDM used as an electrical insulating material was blended with silicone rubber and compatibilizer to improve weatherability, ozone resistance, and dielectric strength. The compatibilizer was prepared by imidizing maleated EPDM with {alpha},{omega}-aminopropyl polydimethylsiloxane. EPDM/ silicone alloy was prepared by blending EPDM and silicone rubber with weight ratio of 9/1, 7/3, 5/5, 3/7 and 1/9, maleated EPDM-polydimethylsiloxane copolymer, and dicumyl peroxide (DCP). The maximum tensile strength of 0.177 kgf/mm{sup 2}, elongation at break of 257%, and dielectric breakdown voltage 362.25 kV/cm were obtained from the alloy prepared with 9 to 1 weight ration of EPDM/silicone. The compatibility of the alloy was confirmed from the thermal characteristics measured using DMA and DSC. The morphology of the alloys was observed with SEM. 7 refs., 8 figs., 1 tab.

Cu-Al alloy formation by thermal annealing of Cu/Al multilayer films deposited by cyclic metal organic chemical vapor deposition

Science.gov (United States)

Moon, Hock Key; Yoon, Jaehong; Kim, Hyungjun; Lee, Nae-Eung

2013-05-01

One of the most important issues in future Cu-based interconnects is to suppress the resistivity increase in the Cu interconnect line while decreasing the line width below 30 nm. For the purpose of mitigating the resistivity increase in the nanoscale Cu line, alloying Cu with traces of other elements is investigated. The formation of a Cu alloy layer using chemical vapor deposition or electroplating has been rarely studied because of the difficulty in forming Cu alloys with elements such as Al. In this work, Cu-Al alloy films were successfully formed after thermal annealing of Cu/Al multilayers deposited by cyclic metal-organic chemical vapor deposition (C-MOCVD). After the C-MOCVD of Cu/Al multilayers without gas phase reaction between the Cu and Al precursors in the reactor, thermal annealing was used to form Cu-Al alloy films with a small Al content fraction. The resistivity of the alloy films was dependent on the Al precursor delivery time and was lower than that of the aluminum-free Cu film. No presence of intermetallic compounds were detected in the alloy films by X-ray diffraction measurements and transmission electron spectroscopy.

The surface chemistry of 3-mercaptopropyltrimethoxysilane films deposited on magnesium alloy AZ91

International Nuclear Information System (INIS)

Scott, A.; Gray-Munro, J.E.

2009-01-01

Magnesium and its alloys have desirable physical and mechanical properties for a number of applications. Unfortunately, these materials are highly susceptible to corrosion, particularly in the presence of aqueous solutions. The purpose of this study is to develop a uniform, non-toxic surface treatment to enhance the corrosion resistance of magnesium alloys. This paper reports the influence of the coating bath parameters and alloy microstructure on the deposition of 3-mercaptopropyltrimethoxysilane (MPTS) coatings on magnesium alloy AZ91. The surface chemistry at the magnesium/MPTS interface has also been explored. The results indicate that the deposition of MPTS onto AZ91 was influenced by both the pH and MPTS concentration in the coating bath. Furthermore, scanning electron microscopy results showed that the MPTS film deposited uniformly on all phases of the magnesium alloy surface. X-ray photoelectron spectroscopy studies revealed that at the magnesium/MPTS interface, the molecules bond to the surface through the thiol group in an acid-base interaction with the Mg(OH) 2 layer, whereas in the bulk of the film, the molecules are randomly oriented.

Soft magnetic properties and damping parameter of (FeCo-Al alloy thin films

Directory of Open Access Journals (Sweden)

Isao Kanada

2017-05-01

Full Text Available For high frequency device applications, a systematic study of the soft magnetic properties and magnetization dynamics of (FeCo-Al alloy thin films has been carried out. A low effective damping parameter αeff of 0.002 and a high saturation magnetization of about 1,800 emu/cc are obtained at y=0.2∼0.3 for (Fe1-yCoy98Al2 alloy thin films deposited onto fused silica and MgO(100 at an ambient temperature during deposition. Those films are of the bcc structure with the orientation normal to the film plane. They possess a columnar structure, grown along the film normal. The column width is found to be about 20 nm for y=0.25. It is concluded that the (FeCo-Al thin films with a damping parameter as low as 0.002 and high saturation magnetization of about 1,800 emu/cc have been successfully fabricated, and that they are potential for future high frequency device applications.

Effects of Alclad Layer and Anodizing Time on Sulfuric Acid Anodizing and Film Properties of 2E12 Aluminum Alloy

Directory of Open Access Journals (Sweden)

CHEN Gao-hong

2017-07-01

Full Text Available Alclad and unclad 2E12 aerospace aluminum alloy were treated by sulfuric acid anodic oxidation. The effects of alclad layer and anodizing time on the anodization behaviour and corrosion resistance of anodic oxide layer on 2E12 aluminum alloy were studied. Surface and cross-section morphology of anodic oxide films were observed by scanning electron microscopy. The electrochemical properties of anodic oxide films were analyzed by potentiodynamic polarization curve and electrochemical impedance spectroscopy. The results show that the protective anodic oxide layers are formed on alclad and unclad 2E12 aluminum alloy. The film thickness increases with anodizing time extending. The copper rich second phase particles lead to more cavity defects and even micro cracks on anodic oxide films of unclad 2E12 aluminum alloy. The anodic oxide films on alclad 2E12 aluminum alloy are thicker and have fewer cavity defects, resulting in better corrosion resistance. The films obtained after 30min and 45min anodic oxidation treatment exhibit lower corrosion current and higher impedance of the porous layer than other anodizing time.

Electrochemical and surface behavior of hydyroxyapatite/Ti film on nanotubular Ti-35Nb-xZr alloys

International Nuclear Information System (INIS)

Jeong, Yong-Hoon; Choe, Han-Cheol; Brantley, William A.

2012-01-01

In this paper, we investigated the electrochemical and surface behavior of hydroxyapatite (HA)/Ti films on the nanotubular Ti-35Nb-xZr alloy. The Ti-35Nb-xZr ternary alloys with 3-10 wt.% Zr content were made by an arc melting method. The nanotubular oxide layers were developed on the Ti-35Nb-xZr alloys by an anodic oxidation method in 1 M H 3 PO 4 electrolyte containing 0.8 wt% NaF at room temperature. The HA/Ti composite films on the nanotubular oxide surfaces were deposited by a magnetron sputtering method. Their surface characteristics were analyzed by field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS) and an X-ray diffractometer (XRD). The corrosion behavior of the specimens was examined through potentiodynamic and AC impedance tests in 0.9% NaCl solution. From the results, the Ti-35Nb-xZr alloys showed a solely β phase microstructure that resulted from the addition of Zr. The nanotubular structure formed with a diameter of about 200 nm, and the HA/Ti thin film was deposited on the nanotubular structure. The HA/Ti thin film-coated nanotubular Ti-35Nb-xZr alloys showed good corrosion resistance in 0.9% NaCl solution.

A novel synthesis method for large area metallic amorphous/nanocrystal films by the glow-discharge plasma technique

International Nuclear Information System (INIS)

Xu Jiang; Xu Zhong; Tao Jie; Liu Zili; Chen Zheyuan; Zhu Wenhui

2007-01-01

Two large-area metallic amorphous/nanocrystal films were prepared on AZ31 magnesium alloy and pure iron substrates by the double glow-discharge plasma technique. The formation mechanism of the novel amorphous films did not follow the established empirical rules for large glass-forming ability. The amorphous films were composed of binary alloys with a difference in the atomic diameter of alloying constituents of less than 12%, and an amorphous film of pure iron was successfully obtained

Characterization of CuIn1-xAlxS2 thin films prepared by thermal evaporation

International Nuclear Information System (INIS)

Smaili, F.; Kanzari, M.; Rezig, B.

2008-01-01

Ingots containing single crystals of the quaternary alloys CuIn 1-x Al x S 2 (CIAS) were grown by a horizontal Bridgman method for compositions with x = 0, 0.2 and x = 0.4. (CIAS) thin films were prepared by thermal evaporation technique on to glass substrates. Structural and optical properties of the films were studied in function of the Al content. Band gap, and absorption coefficients were determined from the analysis of the optical spectra (transmittance and reflectance as a function of wavelength) recorded by a spectrophotometer. The samples have direct bandgap energies of 1.95 eV (x = 0), 2.06 eV (x = 0,2) and 2.1 eV (x = 0,4). These optical results were correlated with the structural analysis by X-Ray diffraction

New Au–Cu–Al thin film shape memory alloys with tunable functional properties and high thermal stability

International Nuclear Information System (INIS)

Buenconsejo, Pio John S.; Ludwig, Alfred

2015-01-01

An Au–Cu–Al thin film materials library prepared by combinatorial sputter-deposition was characterized by high-throughput experimentation in order to identify and assess new shape memory alloys (SMAs) in this alloy system. Automated resistance measurements during thermal cycling between −20 and 250 °C revealed a wide composition range that undergoes reversible phase transformations with martensite transformation start temperatures, reverse transformation finish temperatures and transformation hysteresis ranging from −15 to 149 °C, 5 to 185 °C and 8 to 60 K, respectively. High-throughput X-ray diffraction analysis of the materials library confirmed that the phase-transforming compositions can be attributed to the existence of the β-AuCuAl parent phase and its martensite product. The formation of large amount of phases based on face-centered cubic (Au–Cu), Al–Cu and Al–Au is responsible for limiting the range of phase-transforming compositions. Selected alloys in this system show excellent thermal cyclic stability of the phase transformation. The functional properties of these alloys, combined with the inherent properties of Au-based alloys, i.e. aesthetic value, oxidation and corrosion resistance, makes them attractive as smart materials for a wide range of applications, including applications as SMAs for elevated temperatures in harsh environment

Growth and characterization of NixCu1-x alloy films, NixCu1-x/NiyCu1-y multilayers, and nanowires

International Nuclear Information System (INIS)

Kazeminezhad, I.

2001-12-01

It was found that it is possible to grow Ni x Cu 1-x alloy systems of arbitrary composition by electrodepositing well-defined sub-monolayer quantities of Ni and Cu in alternation using a new method based on that used previously to prepare potentiostatically deposited magnetic multilayers from a single sulphamate-based electrolyte. Following growth, the chemical composition of Ni x Cu 1-x alloy films was obtained by ZAF-corrected energy dispersive X-Ray (EDX) analysis and less than a 4% difference between the nominal and actual composition was observed. The structure of the films was investigated by high-angle X-ray diffractometry (HAXRD) and transmission electron microscopy (TEM). The films grown on polycrystalline Cu substrates had (100) texture, while those grown on Au-coated glass had (111) texture. Some evidence of Ni clustering was obtained by vibrating sample magnetometry (VSM). Self-organisation of the deposited metal was suggested for Ni potentials more positive than ∼-1.4V. The transition from a Ni/Cu multilayer to a Ni x Cu 1-x alloy was also studied and an interesting aspect, namely a plateau region in a plot of magnetisation as a function of Ni layer thickness was observed, suggesting a preferred Ni cluster size in these alloy films. Anisotropic magnetoresistance (AMR) of the films decreased with increasing Cu content at 300K and 77K. SQUID measurements for Ni 0.52 Cu 0.48 and Ni 0.62 CU 0.38 films showed that they become much more strongly ferromagnetic at low temperatures. Evidence for blocked -superparamagnetic behaviour above a blocking temperature (T B ) of the films was obtained from zero-field-cooled (ZFC) and field-cooled (FC) magnetic susceptibility measurements. Ni x Cu 1-x /Ni y Cu 1-y alloy/alloy multilayer films with short repeat distance were successfully fabricated using this method. Up to third order satellite peaks observed in HAXRD showed that the interface is sharp. Room temperature longitudinal magnetoresistance measurements showed

Thermal evolution of nanocrystalline co-sputtered Ni–Zr alloy films: Structural, magnetic and MD simulation studies

International Nuclear Information System (INIS)

Bhattacharya, Debarati; Rao, T.V. Chandrasekhar; Bhushan, K.G.; Ali, Kawsar; Debnath, A.; Singh, S.; Arya, A.; Bhattacharya, S.; Basu, S.

2015-01-01

Monophasic and homogeneous Ni 10 Zr 7 nanocrystalline alloy films were successfully grown at room temperature by co-sputtering in an indigenously developed three-gun DC/RF magnetron sputtering unit. The films could be produced with long-range crystallographic and chemical order in the alloy, thus overcoming the widely acknowledged inherent proclivity of the glass forming Ni–Zr couple towards amorphization. Crystallinity of these alloys is a desirable feature with regard to improved efficacy in applications such as hydrogen storage, catalytic activity and nuclear reactor engineering, to name a few. Thermal stability of this crystalline phase, being vital for transition to viable applications, was investigated through systematic annealing of the alloy films at 473 K, 673 K and 923 K for various durations. While the films were stable at 473 K, the effect of annealing at 673 K was to create segregation into nanocrystalline Ni (superparamagnetic) and amorphous Ni + Zr (non-magnetic) phases. Detailed analyses of the physical and magnetic structures before and after annealing were performed through several techniques effectual in analyzing stratified configurations and the findings were all consistent with each other. Polarized neutron and X-ray reflectometry, grazing incidence x-ray diffraction, time-of-flight secondary ion mass spectroscopy and X-ray photoelectron spectroscopy were used to gauge phase separation at nanometer length scales. SQUID based magnetometry was used to investigate macroscopic magnetic properties. Simulated annealing performed on this system using molecular dynamic calculations corroborated well with the experimental results. This study provides a thorough understanding of the creation and thermal evolution of a crystalline Ni–Zr alloy. - Highlights: • Nanocrystalline Ni 10 Zr 7 alloy thin films deposited successfully by co-sputtering. • Creation of a crystalline alloy in a binary system with a tendency to amorphize. • Quantitative

Thermal evolution of nanocrystalline co-sputtered Ni–Zr alloy films: Structural, magnetic and MD simulation studies

Energy Technology Data Exchange (ETDEWEB)

Bhattacharya, Debarati, E-mail: debarati@barc.gov.in [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Rao, T.V. Chandrasekhar; Bhushan, K.G. [Technical Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Ali, Kawsar [Material Science Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Debnath, A. [Technical Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Singh, S. [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Arya, A. [Material Science Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Bhattacharya, S. [Technical Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Basu, S. [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

2015-11-15

Monophasic and homogeneous Ni{sub 10}Zr{sub 7} nanocrystalline alloy films were successfully grown at room temperature by co-sputtering in an indigenously developed three-gun DC/RF magnetron sputtering unit. The films could be produced with long-range crystallographic and chemical order in the alloy, thus overcoming the widely acknowledged inherent proclivity of the glass forming Ni–Zr couple towards amorphization. Crystallinity of these alloys is a desirable feature with regard to improved efficacy in applications such as hydrogen storage, catalytic activity and nuclear reactor engineering, to name a few. Thermal stability of this crystalline phase, being vital for transition to viable applications, was investigated through systematic annealing of the alloy films at 473 K, 673 K and 923 K for various durations. While the films were stable at 473 K, the effect of annealing at 673 K was to create segregation into nanocrystalline Ni (superparamagnetic) and amorphous Ni + Zr (non-magnetic) phases. Detailed analyses of the physical and magnetic structures before and after annealing were performed through several techniques effectual in analyzing stratified configurations and the findings were all consistent with each other. Polarized neutron and X-ray reflectometry, grazing incidence x-ray diffraction, time-of-flight secondary ion mass spectroscopy and X-ray photoelectron spectroscopy were used to gauge phase separation at nanometer length scales. SQUID based magnetometry was used to investigate macroscopic magnetic properties. Simulated annealing performed on this system using molecular dynamic calculations corroborated well with the experimental results. This study provides a thorough understanding of the creation and thermal evolution of a crystalline Ni–Zr alloy. - Highlights: • Nanocrystalline Ni{sub 10}Zr{sub 7} alloy thin films deposited successfully by co-sputtering. • Creation of a crystalline alloy in a binary system with a tendency to amorphize. �

Influence of structural disorder on the optical and transport properties of Co sub 0 sub . sub 5 sub 0 Ti sub 0 sub . sub 5 sub 0 alloy films

CERN Document Server

Kim, K W; Rhee, J Y; Kudryavtsev, Y V; Ri, H C

2000-01-01

Co sub 0 sub . sub 5 sub 0 Ti sub 0 sub . sub 5 sub 0 alloy films with a total thickness of about 100 nm were prepared by flash evaporation of the crushed alloy powders onto heated (730 K for the ordered state) and LN sub 2 -cooled (150 K for the disordered state) substrates. Structural analysis of the films was performed by suing transmission electron microscopy. The optical conductivity (OC) of the samples was measured at room temperature in a spectral range of 265 -2500 nm (4.7 - 0.5 eV). The resistivity measurements were carried out by using the four-probe technique in a temperature range of 4.2 - 300 K. The experimental OC spectra for the Co sub 0 sub . sub 5 sub 0 Ti sub 0 sub . sub 5 sub 0 alloys show the most significant change in the infrared region upon the order-disorder transformation. The structural disorder in the Co sub 0 sub . sub 5 sub 0 Ti sub 0 sub . sub 5 sub 0 alloy film leads to a change in the sign of the temperature coefficient of the resistivity from positive to negative. The observed...

Electrochemical and Thermal Studies of Prepared Conducting Chitosan Biopolymer Film

International Nuclear Information System (INIS)

Hlaing Hlaing Oo; Kyaw Naing; Kyaw Myo Naing; Tin Tin Aye; Nyunt Wynn

2005-09-01

In this paper, chitosan based conducting bipolymer films were prepared by casting and solvent evaporating technique. All prepared chitosan films were of pale yellow colour, transparent, and smooth. Sulphuric acid was chosen as the cross-linking agent. It enhanced conduction pathway in cross-linked chitosan films. Mechanical properties, solid-state, and thermal behavior of prepared chitosan fimls were studied by means of a material testing machine, powder X-ray diffractometry (XRD), thermogravimetric analysis (TG-DTG), and differential scanning calorimetry (DSC). By the XRD diffraction pattern, high molecular weight of chitosan product indicates the semi-crystalline nature, but the prepared chitosan film and doped chitosan film indicate significantly lower in crystallinity prove which of the amorphous characteristics. In addition, DSC thermogram of pure chitosan film exhibited exothermic peak around at 300 C, indicating polymer decomposition of chitosan molecules in chitosan films. Furthermore, these DSC thermograms clearly showed that while pure chitosan film display exothermal decomposition, the doped chitosan films mainly endothermic characteristics. The ionic conductivity of doped chitosan films were in the order of 10 to 10 S cm , which is in the range of semi-conductor. These results showed that cross-linked chitoson films may be used as polymer electrolyte film to fabricate solid state electrochemical cells

Electrical Properties of a Thin Anodized Capacitor Made of Y-Doped Al Alloy Film

Science.gov (United States)

Onozuka, Tomotake; Sasaki, Hayato; Mikuni, Naohiro; Shinkai, Satoko; Sasaki, Katsutaka; Yamane, Misao; Abe, Yoshio

2005-09-01

We have prepared an Al-Y anodized capacitor using sputter-deposited Al-Y alloy film with 5 at. % Y atoms, and evaluated the capacitor properties and the leakage current properties before and after heat treatment. In addition, the characterization of Al-Y anodized films was examined by X-ray diffraction, Auger electron spectroscopy (AES), and X-ray photoelectron spectroscopy analyses. As a result, it is revealed that the thermal stability of an Al-Y anodized capacitor is superior to that of a pure Al anodized capacitor because of its excellent passive nature, and the loss properties can be improved by increasing the heat treatment temperature in air because of the reduction of the equivalent series resistance. Furthermore, it is clarified that the cause of the short-circuited state observed at 550°C is the formation of a narrow capillary-like conduction path of metallic Al atoms as a result of the interdiffusion of Al.

Investigation of electrochemical behaviour and structure of oxide films on Ni60Nb40 alloy in amorphous and crystalline states

International Nuclear Information System (INIS)

Tomashov, N.D.; Skvortsova, I.B.; Gorodetskij, A.E.; Bogomolov, D.B.

1987-01-01

Electrochemical properties of Ni 60 Nb 40 alloy in amorphous and crystalline states as well as structure of oxide films forming during anode polarization in electrolytes on the surface of this alloy in both its states are investigated. It is stated that increased passive ability of Ni 60 Nb 40 alloys in amorphous state and high efficiency of chlorine evolution (2 n NaCl+HCl up to pH=0) anode process in comparison with crystalline state are defined by increased homogeneity and uniformity of passive films forming on amorphous alloy and their increased electron conductivity, that is in direct dependence on different structure of passive films forming on alloys in amorphous and crystalline states

Effect of heat treatment on Fe-B-Si-Nb alloy powder prepared by mechanical alloying

Directory of Open Access Journals (Sweden)

Rodrigo Estevam Coelho

2005-06-01

Full Text Available The effect of heat treatment on crystallization behavior of Fe73.5B15Si10Nb1.5 alloy powder prepared by mechanical alloying was studied. The powder samples were prepared by mechanical alloying (MA and for different milling times (1, 5, 25, 70 and 100 hours. Crystalline powders of iron, boron, silicon and niobium were sealed with tungsten carbide balls in a cylindrical vial under nitrogen atmosphere. The ball-to-powder weight ratio was 20 to 1. A Fritsch Pulverizette 5 planetary ball mill was used for MA the powders at room temperature and at 250 rpm. To study the microstructural evolution, a small amount of powder was collected after different milling times and examined by X-ray diffraction, using CuKalpha radiation (lambda = 0.15418 nm. The crystallization behavior was studied by differential thermal analysis, from 25 up to 1000 °C at a heating rate of 25 °C min-1.

Magnetization in permalloy thin films

Indian Academy of Sciences (India)

Thin films of permalloy (Ni80Fe20) were prepared using an Ar+N2 mixture with magnetron ... alloys of Ni and Fe) take an important place. NiFe alloy with a ... room temperature (∼298 K, without intentional heating) on Si(100) substrates. A base pressure of 1×10−6 mbar was achieved prior to the deposition. Three different ...

A flexible method for the preparation of thin film samples for in situ TEM characterization combining shadow-FIB milling and electron-beam-assisted etching

Energy Technology Data Exchange (ETDEWEB)

Liebig, J.P., E-mail: jan.p.liebig@fau.de [Department of Materials Science and Engineering, Institute I, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Martensstr. 5, 91058 Erlangen (Germany); Göken, M. [Department of Materials Science and Engineering, Institute I, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Martensstr. 5, 91058 Erlangen (Germany); Richter, G. [Max Planck Institute for Intelligent Systems, Heisenbergstr. 3, 70569 Stuttgart (Germany); Mačković, M.; Przybilla, T.; Spiecker, E. [Institute of Micro, and Nanostructure Research & Center for Nanoanalysis and Electron Microscopy (CENEM), Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Cauerstr. 6, 91058 Erlangen (Germany); Pierron, O.N. [G. W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0405 (United States); Merle, B. [Department of Materials Science and Engineering, Institute I, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Martensstr. 5, 91058 Erlangen (Germany)

2016-12-15

A new method for the preparation of freestanding thin film samples for mechanical testing in transmission electron microscopes is presented. It is based on a combination of focused ion beam (FIB) milling and electron-beam-assisted etching with xenon difluoride (XeF{sub 2}) precursor gas. The use of the FIB allows for the target preparation of microstructural defects and enables well-defined sample geometries which can be easily adapted in order to meet the requirements of various testing setups. In contrast to existing FIB-based preparation approaches, the area of interest is never exposed to ion beam irradiation which preserves a pristine microstructure. The method can be applied to a wide range of thin film material systems compatible with XeF{sub 2} etching. Its feasibility is demonstrated for gold and alloyed copper thin films and its practical application is discussed. - Highlights: • A new method for the preparation of sub-micron tensile specimens from thin films is presented. • The method is based on the combination of focused ion beam milling and electron-beam-assisted xenon difluoride etching. • It enables the target preparation of individual microstructural defects. • The sample section is protected from ion beam damage by the use of a shadow milling geometry.

Low-emissivity coating of amorphous diamond-like carbon/Ag-alloy multilayer on glass

International Nuclear Information System (INIS)

Chiba, Kiyoshi; Takahashi, Toshiyuki; Kageyama, Takashi; Oda, Hironori

2005-01-01

Transparent low-emissivity (low-e) coatings comprising dielectrics of amorphous diamond-like carbon (DLC) and Ag-alloy films are investigated. All films have been prepared by dc magnetron sputtering. An index of refraction of the DLC film deposited in a gas mixture of Ar/H 2 (4%) shows n = 1.80 + 0.047i at 500 nm wavelength. A multilayer stack of DLC (70 nm thick)/Ag 87.5 Cu 12.5 -alloy (10 nm)/DLC (140 nm)/Ag 87.5 Cu 12.5 -alloy (10 nm)/DLC (70 nm) has revealed clear interference spectra with spectra selectivity. This coating performs low emittance less than 0.1 for black body radiation at 297 K, exhibiting a transparent heat mirror property embedded in DLC films

Determination of structural, mechanical and corrosion properties of Nb{sub 2}O{sub 5} and (Nb{sub y}Cu{sub 1−y})O{sub x} thin films deposited on Ti6Al4V alloy substrates for dental implant applications

Energy Technology Data Exchange (ETDEWEB)

Mazur, M. [Wroclaw University of Technology, Faculty of Microsystem Electronics and Photonics, Janiszewskiego 11/17, 50-372 Wroclaw (Poland); Kalisz, M., E-mail: malgorzata.kalisz@its.waw.pl [Motor Transport Institute, Jagiellońska 80, 03-301 Warsaw (Poland); Wojcieszak, D. [Wroclaw University of Technology, Faculty of Microsystem Electronics and Photonics, Janiszewskiego 11/17, 50-372 Wroclaw (Poland); Grobelny, M. [Motor Transport Institute, Jagiellońska 80, 03-301 Warsaw (Poland); Mazur, P. [Wroclaw University, Institute of Experimental Physics, Max Born 9, 50-204 Wroclaw (Poland); Kaczmarek, D.; Domaradzki, J. [Wroclaw University of Technology, Faculty of Microsystem Electronics and Photonics, Janiszewskiego 11/17, 50-372 Wroclaw (Poland)

2015-02-01

In this paper comparative studies on the structural, mechanical and corrosion properties of Nb{sub 2}O{sub 5}/Ti and (Nb{sub y}Cu{sub 1−y})O{sub x}/Ti alloy systems have been investigated. Pure layers of niobia and niobia with a copper addition were deposited on a Ti6Al4V titanium alloy surface using the magnetron sputtering method. The physicochemical properties of the prepared thin films were examined with the aid of XRD, XPS SEM and AFM measurements. The mechanical properties (i.e., nanohardness, Young's modulus and abrasion resistance) were performed using nanoindentation and a steel wool test. The corrosion properties of the coatings were determined by analysis of the voltammetric curves. The deposited coatings were crack free, exhibited good adherence to the substrate, no discontinuity of the thin film was observed and the surface morphology was homogeneous. The hardness of pure niobium pentoxide was ca. 8.64 GPa. The obtained results showed that the addition of copper into pure niobia resulted in the preparation of a layer with a lower hardness of ca. 7.79 GPa (for niobia with 17 at.% Cu) and 7.75 GPa (for niobia with 25 at.% Cu). The corrosion properties of the tested thin films deposited on the surface of titanium alloy depended on the composition of the thin layer. The addition of copper (i.e. a noble metal) to Nb{sub 2}O{sub 5} film increased the corrosion resistance followed by a significant decrease in the value of corrosion currents and, in case of the highest Cu content, the shift of corrosion potential towards the noble direction. The best corrosion properties were obtained from a sample of Ti6Al4V coated with (Nb{sub 0.75}Cu{sub 0.25})O{sub x} thin film. It seems that the tested materials could be used in the future as protection coatings for Ti alloys in biomedical applications such as implants. - Highlights: • Nb{sub 2}O{sub 5} and Nb{sub 2}O{sub 5}:Cu thin films were deposited on a Ti–Al–V surface using the magnetron sputtering. �

The effect of different aluminum alloy surface compositions on barrier anodic film formation

International Nuclear Information System (INIS)

Panitz, J.K.G.; Sharp, D.J.

1984-01-01

The authors have grown barrier anodic coatings on samples of aluminum alloy with different elemental surface compositions. In one series of experiments, they characterized the surface composition present on 6061 aluminum alloy samples after different chemical treatments including a detergent-water and methyl-ethyl ketone solvent clean, a 50% nitric acid-water etch, and a concentrated nitric acid-ammonium bifluoride etch. They anodized samples which were prepared similarly to those analyzed to evaluate the practical effects of the three different surface compositions. The anodization voltage rise time to 950V at constant current was used as a figure of merit. The solvent cleaned and the 50% nitric acid etched samples required, respectively, 113% and 41% more time to reach 950V than the concentrated nitric acidammonium bifloride etched samples. In a second series of experiments, they alternately anodized groups of either 6061 or 1100 (commercially pure) aluminum alloy, observed rise times to 950V, and measured chloride ion concentrations in the electrolyte. Longer rise times and higher chloride ion concentrations were observed for the 1100 samples. It was observed that the chloride ion concentration fell from initially high levels when 6061 samples were anodized. The results of both series of experiments augment the results of other investigators, who report that the surface species initially present on aluminum have a significant effect on anodic film formation

Stability of passive films on amorphous Fe-Cr alloys with boron and phosphorus with impedance spectroscopy

International Nuclear Information System (INIS)

Virtanen, S.; Elsener, B.; Boehni, H.

1989-01-01

The mechanism of the passivation and the effect of metalloids on the stability of the passive films of amorphous Fe-Cr-(B,P,C) alloys has been investigated by polarization measurements, impedance spectroscopy and potential decay measurements. The results show that phosphorus facilitates the active/passive-transition by forming a porous iron-phosphate pre-passive layer on the alloy surface in the active range of the dissolution. This layer blocks the active sites of the surface and accelerates the cathodic H 2 -evolution reaction. The formation of the passivating chromium oxide layer takes place in the pores of this layer. In the passive range of the alloys oxidized phosphorus gets incorporated in the outer layer of the passive film. The presence of oxidized phosphorus as PO 4 3- anions in the passive film increases the localized corrosion resistance in Cl-containing solutions. The effect of the incorporated phosphates in the passive film is discussed with respect to the bipolar fixed-charge induced passivity model. The phosphates make the outer layer of the passive film cation-selective and thus hinder the penetration of the chlorides into the film. The oxidized boron species cannot change the ion-selectivity of the film; instead of this they negatively affect the stability of the passive film. (author) 18 refs., 9 figs., 3 tabs

Preparation of self-supporting thin metal target films

International Nuclear Information System (INIS)

Wang Xiuying; Ge Suxian; Yin Jianhua; Yin Xu; Jin Genming

1989-01-01

The preparation method and equipment for thin metal self-supporting target without oil contamination are described. The influence of target films contaminated by oil vapor on accuracy of nuclear-physics experimental data are also discussed. The analytical results on carbon content in the prepared films of three elements show that the equipment is very effective for eliminating contamination

Reduction in the formation temperature of Poly-SiGe alloy thin film in Si/Ge system

Science.gov (United States)

Tah, Twisha; Singh, Ch. Kishan; Madapu, K. K.; Sarguna, R. M.; Magudapathy, P.; Ilango, S.

2018-04-01

The role of deposition temperature in the formation of poly-SiGe alloy thin film in Si/Ge system is reported. For the set ofsamples deposited without any intentional heating, initiation of alloying starts upon post annealingat ˜ 500 °C leading to the formation of a-SiGe. Subsequently, poly-SiGe alloy phase could formonly at temperature ≥ 800 °C. Whereas, for the set of samples deposited at 500 °C, in-situ formation of poly-SiGe alloy thin film could be observed. The energetics of the incoming evaporated atoms and theirsubsequent diffusionsin the presence of the supplied thermal energy is discussed to understand possible reasons for lowering of formation temperature/energyof the poly-SiGe phase.

Boric/sulfuric acid anodizing of aluminum alloys 2024 and 7075: Film growth and corrosion resistance

Energy Technology Data Exchange (ETDEWEB)

Thompson, G.E.; Zhang, L.; Smith, C.J.E.; Skeldon, P.

1999-11-01

The influence of boric acid (H{sub 3}BO{sub 3}) additions to sulfuric acid (H{sub 2}SO{sub 4}) were examined for the anodizing of Al 2024-T3 (UNS A92024) and Al 7075-T6 (UNS A97075) alloys at constant voltage. Alloys were pretreated by electropolishing, by sodium dichromate (Na{sub 2}Cr{sub 2}O{sub 7})/H{sub 2}SO{sub 4} (CSA) etching, or by alkaline etching. Current-time responses revealed insignificant dependence on the concentration of H{sub 3}BO{sub 3} to 50 g/L. Pretreatments affected the initial film development prior to the establishment of the steady-state morphology of the porous film, which was related to the different compositions and morphologies of pretreated surfaces. More detailed studies of the Al 7075-T6 alloy indicated negligible effects of H{sub 3}BO{sub 3} on the coating weight, morphology of the anodic film, and thickening rate of the film, or corrosion resistance provided by the film. In salt spray tests, unsealed films formed in H{sub 2}SO{sub 4} or mixed acid yielded similar poor corrosion resistances, which were inferior to that provided by anodizing in chromic acid (H{sub 2}CrO{sub 4}). Sealing of films in deionized water, or preferably in chromate solution, improved corrosion resistance, although not matching the far superior performance provided by H{sub 2}CrO{sub 4} anodizing and sealing.

Study of structural relaxation in amorphous alloys prepared by sputtering

International Nuclear Information System (INIS)

Habibi, S.; Banaee, N.; Majidy, S.

2004-01-01

Full text: We have prepared amorphous alloy of Al x Cu 1-x (with X= 93, 90, 80, 70, 30) using sputtering system. The rate of growth was 0.7 nm/sec. X-ray diffractometer was used to conform the amorphous nature of the prepared specimens. High temperature annealing can change amorphous to crystalline structure, while low temperature annealing may transform amorphous state to a more stable amorphous state via structural relaxation of the specimen and enhancing the properties of the alloys, such as mechanical ductility etc. Here we have annealed the alloys at temperatures 100, 150, 200, 250, 300 and 350 C for 1 hour. We observed that microhardness of the specimen increases with annealing and gets maximum value at 300 C. Our XRD experiments and also earlier Moessbauer studies show that while the average interatomic distances reduces due to annealing, structure remains amorphous

Characterization of Dispersion Strengthened Copper Alloy Prepared by Internal Oxidation Combined with Mechanical Alloying

Science.gov (United States)

Zhao, Ziqian; Xiao, Zhu; Li, Zhou; Zhu, Mengnan; Yang, Ziqi

2017-11-01

Cu-3.6 vol.% Al2O3 dispersion strengthened alloy was prepared by mechanical alloying (MA) of internal oxidation Cu-Al powders. The lattice parameter of Cu matrix decreased with milling time for powders milled in argon, while the abnormal increase of lattice parameter occurred in the air resulting from mechanochemical reactions. With a quantitative analysis, the combined method makes residual aluminum oxidized completely within 10-20 h while mechanical alloying method alone needs longer than 40 h. Lamellar structure formed and the thickness of lamellar structure decreased with milling time. The size of Al2O3 particles decreased from 46 to 22 nm after 40 h milling. After reduction, core-shell structure was found in MAed powders milled in the air. The compacted alloy produced by MAed powders milled in the argon had an average hardness and electrical conductivity of 172.2 HV and 82.1% IACS while the unmilled alloy's were 119.8 HV and 74.1% IACS due to the Al2O3 particles refinement and residual aluminum in situ oxidization.

The impedance properties of the oxide film on the Ni-Cr-Mo Alloy-22 in neutral concentrated sodium chloride solution

Energy Technology Data Exchange (ETDEWEB)

Jakupi, P.; Zagidulin, D.; Noel, J.J. [Department of Chemistry, University of Western Ontario, London, Ontario, N6A-3K7 (Canada); Shoesmith, D.W., E-mail: dwshoesm@uwo.ca [Department of Chemistry, University of Western Ontario, London, Ontario, N6A-3K7 (Canada)

2011-07-01

The oxide film properties on Alloy-22 in the applied potential (E) range -600 mV to 600 mV (vs. saturated KCl, Ag/AgCl reference electrode) were characterized by Electrochemical Impedance Spectroscopy (EIS) in near neutral pH, 5 M NaCl solutions, at 30 deg. C. The impedance properties of the film were compared to the chromium content of the film determined by X-ray photoelectron spectroscopy (XPS). The oxide film properties on Alloy-22 may be divided into three applied potential (E) ranges: -600 mV {<=} E < -300 mV, -300 mV {<=} E {<=} 300 mV, and E > 300 mV. For the range -600 mV {<=} E < -300 mV the film resistance (R{sub film}) increases with potential accompanied by an increase in Cr{sub 2}O{sub 3} content; in the range -300 mV {<=} E {<=} 300 mV, R{sub film} values and the Cr{sub 2}O{sub 3} content of the oxide film achieve their maximum values; for E > 300 mV, a decrease in both R{sub film} and Cr{sub 2}O{sub 3} is observed accompanied by a significant increase in Cr(OH){sub 3}. Comparison of the impedance properties for Alloy-22 to those of Ni-Cr alloys indicate that the barrier layer oxide on Alloy-22 contains a lower number of less mobile defects, most likely Cr interstitials. Destruction of the barrier layer for E > 300 mV leads to the formation of a thicker, less protective bilayer, which is high in Mo content.

Influence of dissolved hydrogen on oxide film and PWSCC of Alloy 600 in PWR primary water

Energy Technology Data Exchange (ETDEWEB)

Nakagawa, Tomokazu; Totsuka, Nobuo; Nakajima, Nobuo [Institute of Nuclear Safety System Inc., Mihama, Fukui (Japan)

2001-09-01

In order to investigate the influence of dissolved hydrogen (DH) on the corrosion behavior and PWSCC of Alloy 600 in primary water of PWR under actual operating temperature range, we carried out electrochemical polarization measurement, repassivation test, analysis of the oxide film on the alloy by AES, XPS and PWSCC test. In all cases, the content of DH was changed from 0 to 45 cc/kgH{sub 2}O. The anodic polarization curve reveals that the peak current density increases with increasing DH. The result of the repassivation test shows that the repassivation rate decreases with increasing DH, and the changes of the above two become larger between 11 and 22 cc/kgH{sub 2}O of DH. According to the results of oxide film analysis, it is seen that the oxide films formed below 11 cc/kgH{sub 2}O of DH are relatively thick and rich in Ni, but those formed at higher DH contents are relatively thin and rich in Cr and Fe. The susceptibility of the alloy to PWSCC has a peak at 11 cc/kgH{sub 2}O of DH, which reveals that the property of the oxide film may play important role in PWSCC of alloy. (author)

Pt_xGd alloy formation on Pt(111): Preparation and structural characterization

DEFF Research Database (Denmark)

Ulrikkeholm, Elisabeth Therese; Pedersen, Anders Filsøe; Vej-Hansen, Ulrik Grønbjerg

2016-01-01

(ring operator)C. The LEED and synchrotron XRD experiments have shown that a slightly compressed (2 ×2) alloy appear. The alloy film followed the orientation of the Pt(111) substrate half the time, otherwise it was rotated by 30(ring operator). The TPD spectra show a well-defined peak shifted down 200...

Formation and structure of V-Zr amorphous alloy thin films

KAUST Repository

King, Daniel J M

2015-01-01

Although the equilibrium phase diagram predicts that alloys in the central part of the V-Zr system should consist of V2Zr Laves phase with partial segregation of one element, it is known that under non-equilibrium conditions these materials can form amorphous structures. Here we examine the structures and stabilities of thin film V-Zr alloys deposited at room temperature by magnetron sputtering. The films were characterized by X-ray diffraction, transmission electron microscopy and computational methods. Atomic-scale modelling was used to investigate the enthalpies of formation of the various competing structures. The calculations confirmed that an amorphous solid solution would be significantly more stable than a random body-centred solid solution of the elements, in agreement with the experimental results. In addition, the modelling effort provided insight into the probable atomic configurations of the amorphous structures allowing predictions of the average distance to the first and second nearest neighbours in the system.

Effect of the reinforced boron carbide particulate content of AA6061 alloy on formation of the passive film in seawater

International Nuclear Information System (INIS)

Katkar, V.A.; Gunasekaran, G.; Rao, A.G.; Koli, P.M.

2011-01-01

Highlights: → Presence of boron carbide increases the corrosion rate of A6061 alloy in seawater. → Increasing the B 4 C content decreases passive layer thickness. → Passive films formed on A6061 and its B 4 C composites are n-type semiconductors. - Abstract: The effect of boron carbide (B 4 C) reinforcement on the corrosion of AA6061 alloy was studied by investigating passive films formed in seawater. The higher passive current and its potential-dependence for these composites indicated formation of porous passive film. Electrochemical impedance spectroscopy (EIS) graph suggests that the alloy surface is partly or totally active. The formed passive film is n-type semiconductor junction in nature. The difference between corrosion potential (E corr ) and potential at zero charge (PZC) suggests that the chloride ions responsible for film breakdown exist within the passive film. A suitable mechanism is proposed for the passive film breakdown.

Effect of plasma molybdenized buffer layer on adhesive properties of TiN film coated on Ti6Al4V alloy

Energy Technology Data Exchange (ETDEWEB)

Qin, Lin, E-mail: qinlin@tyut.edu.cn; Yi, Hong; Kong, Fanyou; Ma, Hua; Guo, Lili; Tian, Linhai; Tang, Bin

2017-05-01

Highlights: • A molybdenized layer was prepared as a buffer layer under TiN film on Ti6Al4V. • The molybdenized layer can enhance adhesion strength of PVD coatings effectively. • The duplex treated samples increase elastic energy ratio in the impact tests. • The enhancement attributes to the hardness improvement and inverted-S shape elastic modulus profile of the modified layer. - Abstract: Effect of molybdenized buffer layer on adhesion strength of TiN film on Ti6Al4V alloy was investigated. The buffer layer composed of a dense molybdenum deposition layer, a rapid drop zone and a slow fall zone was prepared using double glow plasma surface alloying technique. Scratch tests and low energy repeated impact tests were adopted to comparatively evaluate the duplex treated layers and the single TiN samples. The results show that the critical load was increased from 62 N for the single TiN film to over 100 N for the duplex treated layer. The volume of impact pit, formed in impact tests, of the single TiN samples is 9.15 × 10{sup 6} μm{sup 3}, and about 1.5 times than that of the duplex treated samples. The Leeb hardness values reveal that about 70% impact energy was transferred to the single TiN samples to generate permanent deformation, while that was only about 47% for the duplex treated samples. The mechanism of improving adhesion strength is attributed to synergistic effect due to an inverted-S shape elastic modulus distribution produced by the molybdenized layer.

Preparation and characterisation of Al-doped Zn O thin films

International Nuclear Information System (INIS)

Saad, M.; Kassis, A.; Nounou, F.

2010-12-01

Al-doped Zn O thin films were prepared using RF magnetron sputtering under several preparation conditions (deposition pressure, RF power, substrate temperature). The films were optically and electrically characterized by measuring their transmission and resistance. Furthermore, x-ray diffraction spectroscopy was used in order to study the structural properties of these films. As a result of this study, the preparation conditions suitable for the highly conductive part of the window layer in solar cells were determined. (author)

Amorphous bimetallic alloys prepared by steam condensation

International Nuclear Information System (INIS)

Drago, V.

1988-01-01

Amorphous alloys of MnSn are prepared by steam condensation, in a substratum with a temperature near of the liquid helium. The magnetic and paramagnetic hyperfine spectrum and the ordination temperature by Moessbauer effect 119Sn are measured. A diagram of magnetic phase is proposed, basing on the measures of Moessbauer effect. (C.G.C.) [pt

First principles investigation of the activity of thin film Pt, Pd and Au surface alloys for oxygen reduction

DEFF Research Database (Denmark)

Tripkovic, Vladimir; Hansen, Heine Anton; Rossmeisl, Jan

2015-01-01

driving force for surface segregation, diffusion to defects or surface self-assembling. On the basis of stability and activity analysis we conclude that the near surface alloy of Pd in Pt and some PdAu binary and PtPdAu ternary thin films with a controlled amount of Au are the best catalysts for oxygen......Further advances in fuel cell technologies are hampered by kinetic limitations associated with the sluggish cathodic oxygen reduction reaction. We have investigated a range of different formulations of binary and ternary Pt, Pd and Au thin films as electrocatalysts for oxygen reduction. The most...... active binary thin films are near-surface alloys of Pt with subsurface Pd and certain PdAu and PtAu thin films with surface and/or subsurface Au. The most active ternary thin films are with pure metal Pt or Pd skins with some degree of Au in the surface and/or subsurface layer and the near-surface alloys...

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.

ITO films deposited by rf-PERTE on unheated polymer substrates--properties dependence on In-Sn alloy composition

International Nuclear Information System (INIS)

Nunes de Carvalho, C.; Lavareda, G.; Fortunato, E.; Vilarinho, P.; Amaral, A.

2004-01-01

The study of the influence of different tin concentrations in the In-Sn alloy on the properties of indium tin oxide (ITO) thin films deposited by radio frequency (rf) plasma enhanced reactive thermal evaporation (rf-PERTE) onto flexible polymer and window glass substrates at room temperature is presented. The polymer substrate used is polyethylene terephthalate (PET). The tin concentration in the source alloy varied in the range 5-20 wt.%. The average thickness of the ITO films is of about 90 nm. Results show that ITO thin films deposited on PET from the evaporation of a 85%In:15%Sn alloy exhibit the following characteristics: an average visible transmittance of 80% and an electrical resistivity of 1.6x10 -3 Ω cm. On glass the value of the average visible transmittance increases (85%) and the resistivity decreases to 7.6x10 -4 Ω cm. The electrical properties of ITO films on PET are largely affected by the low carrier mobility

Preparation of three-dimensional shaped aluminum alloy foam by two-step foaming

International Nuclear Information System (INIS)

Shang, J.T.; Xuming, Chu; Deping, He

2008-01-01

A novel method, named two-step foaming, was investigated to prepare three-dimensional shaped aluminum alloy foam used in car industry, spaceflight, packaging and related areas. Calculations of thermal decomposition kinetics of titanium hydride showed that there is a considerable amount of hydrogen releasing when the titanium hydride is heated at a relatively high temperature after heated at a lower temperature. The hydrogen mass to sustain aluminum alloy foam, having a high porosity, was also estimated by calculations. Calculations indicated that as-received titanium hydride without any pre-treatment can be used as foaming agents in two-step foaming. The processes of two-step foaming, including preparing precursors and baking, were also studied by experiments. Results showed that, low titanium hydride dispersion temperature, long titanium hydride dispersion time and low precursors porosity are beneficial to prepare three-dimensional shaped aluminum alloy foams with uniform pores

Microhardness variation and related microstructure in Al-Cu alloys prepared by HF induction melting and RF sputtering

Science.gov (United States)

Boukhris, N.; Lallouche, S.; Debili, M. Y.; Draissia, M.

2009-03-01

The materials under consideration are binary aluminium-copper alloys (10 at% to 90.3 at%Cu) produced by HF melting and RF magnetron sputtering. The resulting micro structures have been observed by standard metallographic techniques, X-ray powder diffraction, scanning electron microscopy and transmission electron microscopy. Vickers microhardness of bulk Al-Cu alloys reaches a maximum of 1800 MPa at 70.16 at%Cu. An unexpected metastable θ ' phase has been observed within aluminium grain in Al-37 at%Cu. The mechanical properties of a family of homogeneous Al{1-x}Cu{x} (0 Al-Cu targets have been investigated. The as-deposited microstructures for all film compositions consisted of a mixture of the two expected face-centred-cubic (fcc) Al solid solution and tetragonal θ (Al{2}Cu) phases. The microhardness regularly increases and the grain size decreases both with copper concentration. This phenomenon of significant mechanical strengthening of aluminium by means of copper is essentially due to a combination between solid solution effects and grain size refinement. This paper reports some structural features of different Al-Cu alloys prepared by HF melting and RF magnetron on glass substrate sputtering.

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.

Effect of oxide film formation on the fatigue behavior of aluminum alloy

International Nuclear Information System (INIS)

Kim, Jong Cheon; Cheong, Seong Kyun

2012-01-01

In this study, the effects of surface oxide film formation on the fatigue behavior of 7075-T6 aluminum alloy were analyzed in terms of the corrosion time of the alloy. The aluminum material used is known to have high corrosion resistance due to the passivation phenomenon that prevents corrosion. Aluminum alloys have been widely used in various industrial applications such as aircraft component manufacturing because of their lighter weight and higher strength than other materials. Therefore, studies on the fatigue behavior of materials and passivation properties that prevent corrosion are required. The fatigue behavior in terms of the corrosion time was analyzed by using a four pointing bending machine, and the surface corrosion level of the aluminum material in terms of the corrosion time was estimated by measuring the surface were studied by scanning electron microscopy (SEM). The results indicated that corrosion actively progressed for four weeks during the initial corrosion phase, the fatigue life significantly decreased, and the surface roughness increased. However, after four weeks, the corrosion reaction tended to slow down due to the passivation phenomenon of the material. Therefore, on the basis of SEM analysis results, it was concluded that the growth of the surface oxide film was reduced after four weeks and then the oxide film on the material surface served as a protection layer and prevented further corrosion

First principles investigation of the activity of thin film Pt, Pd and Au surface alloys for oxygen reduction

DEFF Research Database (Denmark)

Tripkovic, Vladimir; Hansen, Heine Anton; Rossmeisl, Jan

2015-01-01

Further advances in fuel cell technologies are hampered by kinetic limitations associated with the sluggish cathodic oxygen reduction reaction. We have investigated a range of different formulations of binary and ternary Pt, Pd and Au thin films as electrocatalysts for oxygen reduction. The most...... active binary thin films are near-surface alloys of Pt with subsurface Pd and certain PdAu and PtAu thin films with surface and/or subsurface Au. The most active ternary thin films are with pure metal Pt or Pd skins with some degree of Au in the surface and/or subsurface layer and the near-surface alloys...

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

Spontaneous magnetization of thin films of ordered and disordered alloys of transition metals

International Nuclear Information System (INIS)

Nguyen Nhat Khanh.

1989-12-01

A method of calculation of spontaneous magnetization of thin films of transition metal alloys is described. The method is based on the Hubbard model for d electrons. Use of the Bragg-Williams approximation and two-dimensional canonical transformations has allowed to calculate the magnetization. Results for a Ni 3 Fe thin film are presented. (author). 11 refs, 1 fig

A study on electrodeposited NixFe1−x alloy films

Indian Academy of Sciences (India)

on the magnetic and magnetoresistance properties of NiFe alloy films are mostly focused on the ... is clear from the figure that the Ni deposit content is measured to be 42 wt% for .... grain size change, the degree of ferromagnetic coupling etc.

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.

Effect of chromium and phosphorus on the physical properties of iron and titanium-based amorphous metallic alloy films

Science.gov (United States)

Distefano, S.; Rameshan, R.; Fitzgerald, D. J.

1991-01-01

Amorphous iron and titanium-based alloys containing various amounts of chromium, phosphorus, and boron exhibit high corrosion resistance. Some physical properties of Fe and Ti-based metallic alloy films deposited on a glass substrate by a dc-magnetron sputtering technique are reported. The films were characterized using differential scanning calorimetry, stress analysis, SEM, XRD, SIMS, electron microprobe, and potentiodynamic polarization techniques.

Preparation and characterization of porphyrin-polythiophene stacked films as prepared by electrochemical method under stirring condition

International Nuclear Information System (INIS)

Sugawa, Kosuke; Akiyama, Tsuyoshi; Yamada, Sunao

2008-01-01

Porphyrin-polythiophene (pTh) stacked films consisting of meso-tetrathienylporphyrin (TThP) and bithiophene (BiTh) were prepared on transparent indium-tin-oxide (ITO) electrodes by sequential electrochemical scanning of applied potential between 0 and + 2 V vs Ag wire in the electrolyte solution of BiTh and TThP under stirring condition. First, the pTh films were prepared by electrochemical polymerization and then TThP was incorporated into the as-prepared pTh film by subsequent electrochemical scanning as described above in the TThP solution. The operation of solution stirring during electrochemical scanning achieved the formation of robust stacked films. UV/Vis and fluorescence spectra confirmed that the amount of TThP moiety increased with increasing the number of electrochemical scanning cycles in the TThP solution. In order to evaluate the incorporation profile of TThP, surface analyses and depth profiles of stacked films were carried out by XPS spectroscopy. The results suggested that all films formed porphyrin-polythiophene stacked structure precisely, and that TThP was exclusively incorporated around the outermost region of the pTh film

Mössbauer study of oxide films of Fe-, Sn-, Cr- doped zirconium alloys during corrosion in autoclave

Energy Technology Data Exchange (ETDEWEB)

Filippov, V. P., E-mail: vpfilippov@mephi.ru; Bateev, A. B.; Lauer, Yu. A. [National Research Nuclear University “MEPhI” (Moscow Engineering Physics Institute) (Russian Federation)

2016-12-15

Mössbauer investigations were used to compare iron atom states in oxide films of binary Zr-Fe, ternary Zr-Fe-Cu and quaternary Zr-Fe-Cr-Sn alloys. Oxide films are received in an autoclave at a temperature of 350–360 °C and at pressure of 16.8 MPa. The corrosion process decomposes the intermetallic precipitates in alloys and forms metallic iron with inclusions of chromium atoms α–Fe(Cr), α–Fe(Cu), α–Fe {sub 2}O{sub 3} and Fe {sub 3}O{sub 4} compounds. Some iron ions are formed in divalent and in trivalent paramagnetic states. The additional doping influences on corrosion kinetics and concentration of iron compounds and phases formed in oxide films. It was shown the correlation between concentration of iron in different chemical states and corrosion resistance of alloys.

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

Electrochemical performance of Sn-Sb-Cu film anodes prepared by layer-by-layer electrodeposition

International Nuclear Information System (INIS)

Jiang Qianlei; Xue Ruisheng; Jia Mengqiu

2012-01-01

A novel layer-by-layer electrodeposition and heat-treatment approach was attempted to obtain Sn-Sb-Cu film anode for lithium ion batteries. The preparation of Sn-Sb-Cu anodes started with galvanostatic electrochemically depositing antimony and tin sequentially on the substrate of copper foil collector. Sn-Sb and Cu-Sb alloys were formed when heated. The SEM analysis showed that the crystalline grains become bigger and the surface of the Sn-Sb-Cu anode becomes more denser after annealing. The energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) analysis showed the antimony, tin and copper were alloyed to form SnSb and Cu 2 Sb after heat treatment. The X-ray photoelectron spectroscopy (XPS) analysis showed the surface of the Sn-Sb-Cu electrode was covered by a thin oxide layer. Electrochemical measurements showed that the annealed Sn-Sb-Cu anode has high reversible capacity and good capacity retention. It exhibited a reversible capacity of about 962 mAh/g in the initial cycle, which still remained 715 mAh/g after 30 cycles.

Direct preparation of Al-base alloys from their oxides/metal precursors in the eutectic LiCl–KCl melt

International Nuclear Information System (INIS)

Gao, Bingliang; Zhu, Hao; Xia, Yuxiang; Shi, Zhongning; Hu, Xianwei; Wang, Zhaowen

2016-01-01

A study was carried out on the preparation of Al–Cu–Li alloy from their oxides/metal precursors using the method of electro-deoxidation in the eutectic LiCl–KCl melt at 648 K. Cyclic voltammetry was used to characterize the system. The samples were prepared by potentiostatic electrolysis at −1.0 V to −2.0 V (vs. Ag + /Ag) for 5 h. XRD analysis shows that Li 2 O is not electrochemically reduced to Li at −1.0 V (vs. Ag + /Ag) or more negative potential. During the preparation process of Al–Cu–Li alloy, lithium peroxide is formed as an intermediate compound. Al–Cu–Li alloy is chemically prepared through the reaction between aluminum and lithium peroxide by heating of Al–Cu–Li 2 O precursors in KCl–LiCl–LiF melt at 1023 K. Eelectro-deoxidation in LiCl–KCl melt can increase the lithium content in the final alloy product. Al–Mg and Al–Nd alloy were also prepared by using the same method from their mixture of aluminum and corresponding oxide, respectively. Al–Nd alloy can only be obtained at the temperature above 773 K. Al–Li alloy could not be obtained in eutectic CaCl 2 –LiCl melt because of formation of calcium aluminates. - Highlights: • Al–Cu–Li alloy was prepared using electrochemical deoxidation of Al–Cu–Li 2 O precursor in eutectic KCl–LiCl melt at 648 K. • Al–Nd alloy was successfully produced by the same method at 773 K. • CaCl 2 –LiCl melt is not a good choice for preparing Al–Li alloy because of formation of calcium aluminate.

Direct preparation of Al-base alloys from their oxides/metal precursors in the eutectic LiCl–KCl melt

Energy Technology Data Exchange (ETDEWEB)

Gao, Bingliang, E-mail: blgao@mail.neu.edu.cn; Zhu, Hao; Xia, Yuxiang; Shi, Zhongning; Hu, Xianwei; Wang, Zhaowen

2016-04-25

A study was carried out on the preparation of Al–Cu–Li alloy from their oxides/metal precursors using the method of electro-deoxidation in the eutectic LiCl–KCl melt at 648 K. Cyclic voltammetry was used to characterize the system. The samples were prepared by potentiostatic electrolysis at −1.0 V to −2.0 V (vs. Ag{sup +}/Ag) for 5 h. XRD analysis shows that Li{sub 2}O is not electrochemically reduced to Li at −1.0 V (vs. Ag{sup +}/Ag) or more negative potential. During the preparation process of Al–Cu–Li alloy, lithium peroxide is formed as an intermediate compound. Al–Cu–Li alloy is chemically prepared through the reaction between aluminum and lithium peroxide by heating of Al–Cu–Li{sub 2}O precursors in KCl–LiCl–LiF melt at 1023 K. Eelectro-deoxidation in LiCl–KCl melt can increase the lithium content in the final alloy product. Al–Mg and Al–Nd alloy were also prepared by using the same method from their mixture of aluminum and corresponding oxide, respectively. Al–Nd alloy can only be obtained at the temperature above 773 K. Al–Li alloy could not be obtained in eutectic CaCl{sub 2}–LiCl melt because of formation of calcium aluminates. - Highlights: • Al–Cu–Li alloy was prepared using electrochemical deoxidation of Al–Cu–Li{sub 2}O precursor in eutectic KCl–LiCl melt at 648 K. • Al–Nd alloy was successfully produced by the same method at 773 K. • CaCl{sub 2}–LiCl melt is not a good choice for preparing Al–Li alloy because of formation of calcium aluminate.

Alloy composition dependence of formation of porous Ni prepared by rapid solidification and chemical dealloying

Energy Technology Data Exchange (ETDEWEB)

Qi Zhen [Key Laboratory of Liquid Structure and Heredity of Materials, Shandong University, Jingshi Road 73, Jinan 250061 (China); Zhang Zhonghua [Key Laboratory of Liquid Structure and Heredity of Materials, Shandong University, Jingshi Road 73, Jinan 250061 (China)], E-mail: zh_zhang@sdu.edu.cn; Jia Haoling [Key Laboratory of Liquid Structure and Heredity of Materials, Shandong University, Jingshi Road 73, Jinan 250061 (China); Qu Yingjie [Shandong Labor Occupational Technology College, Jingshi Road 388, Jinan 250022 (China); Liu Guodong; Bian Xiufang [Key Laboratory of Liquid Structure and Heredity of Materials, Shandong University, Jingshi Road 73, Jinan 250061 (China)

2009-03-20

In this paper, the effect of alloy composition on the formation of porous Ni catalysts prepared by chemical dealloying of rapidly solidified Al-Ni alloys has been investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis and N{sub 2} adsorption experiments. The experimental results show that rapid solidification and alloy composition have a significant effect on the phase constituent and microstructure of Al-Ni alloys. The melt spun Al-20 at.% Ni alloy consists of {alpha}-Al, NiAl{sub 3} and Ni{sub 2}Al{sub 3}, while the melt spun Al-25 and 31.5 at.% Ni alloys comprise NiAl{sub 3} and Ni{sub 2}Al{sub 3}. Moreover, the formation and microstructure of the porous Ni catalysts are dependent upon the composition of the melt spun Al-Ni alloys. The morphology and size of Ni particles in the Ni catalysts inherit from those of grains in the melt spun Al-Ni alloys. Rapid solidification can extend the alloy composition of Al-Ni alloys suitable for preparation of the Ni catalysts, and obviously accelerate the dealloying process of the Al-Ni alloys.

Preparation and performance of Ecobras/bentonite biodegrading films

International Nuclear Information System (INIS)

Costa, Ana Nery M.; Melo, Nadja M.C.; Canedo, Eduardo L.; Carvalho, Laura H.; Araujo, Arthur R.A.

2011-01-01

Compounds based on the biodegradable polymer Ecobras and bentonite clay in its pristine, sonicated, and organically modified with a quaternary ammonium salt forms were prepared as flat films. Clays and compounds were characterized by x-ray diffraction and scanning electron microscopy. Mechanical properties of the films were determined according to pertinent ASTM standards. Reasonable properties, higher than those of the matrix, were obtained with compounds prepared with purified clays and organoclays, particularly for low clay loading. (author)

Photoluminescence spectroscopy and positron annihilation spectroscopy probe of alloying and annealing effects in nonpolar m-plane ZnMgO thin films

Science.gov (United States)

Yang, A. L.; Song, H. P.; Liang, D. C.; Wei, H. Y.; Liu, X. L.; Jin, P.; Qin, X. B.; Yang, S. Y.; Zhu, Q. S.; Wang, Z. G.

2010-04-01

Temperature-dependent photoluminescence characteristics of non-polar m-plane ZnO and ZnMgO alloy films grown by metal organic chemical vapor deposition have been studied. The enhancement in emission intensity caused by localized excitons in m-plane ZnMgO alloy films was directly observed and it can be further improved after annealing in nitrogen. The concentration of Zn vacancies in the films was increased by alloying with Mg, which was detected by positron annihilation spectroscopy. This result is very important to directly explain why undoped Zn1-xMgxO thin films can show p-type conduction by controlling Mg content, as discussed by Li et al. [Appl. Phys. Lett. 91, 232115 (2007)].

Preparation of Iron-nickel Alloy Nanostructures via Two Cationic Pyridinium Derivatives as Soft Templates

Directory of Open Access Journals (Sweden)

Jingxin Zhou

2015-09-01

Full Text Available In this paper, crystalline iron-nickel alloy nanostructures were successfully prepared from two cationic pyridinium derivatives as soft templates in solution. The crystal structure and micrograph of FeNi alloy nanostructures were characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy, and the content was confirmed by energy-dispersive spectrometry. The results indicated that the as-prepared nanostructures showed slightly different diameter ranges with the change of cationic pyridinium derivatives on the surface. The experimental data indicated that the adsorption of cationic pyridinium compounds on the surface of particles reduces the surface charge, leading to an isotropic distribution of the residual surface charges. The magnetic behaviours of as-prepared FeNi alloy nanostructures exhibited disparate behaviours, which could be attributed to their grain sizes and distinctive structures. The present work may give some insight into the synthesis and character of new alloy nanomaterials with special nanostructures using new soft templates.

The stability of DLC film on nitrided CoCrMo alloy in phosphate buffer solution

International Nuclear Information System (INIS)

Zhang, T.F.; Liu, B.; Wu, B.J.; Liu, J.; Sun, H.; Leng, Y.X.; Huang, N.

2014-01-01

CoCrMo alloy is often used as the material for metal artificial joint, but metal debris and metal ions are the main concern on tissue inflammation or tissue proliferation for metal prosthesis. In this paper, nitrogen ion implantation and diamond like carbon (DLC) film composite treatment was used to reduce the wear and ion release of biomedical CoCrMo substrate. The mechanical properties and stability of N-implanted/DLC composite layer in phosphate buffer solution (PBS) was evaluated to explore the full potential of N-implanted/DLC composite layer as an artificial joint surface modification material. The results showed that the DLC film on N implanted CoCrMo (N-implanted/DLC composite layer) had the higher surface hardness and wear resistance than the DLC film on virgin CoCrMo alloy, which was resulted from the strengthen effect of the N implanted layer on CoCrMo alloy. After 30 days immersion in PBS, the structure of DLC film on virgin CoCrMo or on N implanted CoCrMo had no visible change. But the adhesion and corrosion resistance of DLC on N implanted CoCrMo (N-implanted/DLC composite layer) was weakened due to the dissolution of the N implanted layer after 30 days immersion in PBS. The adhesion reduction of N-implanted/DLC composite layer was adverse for in vivo application in long term. So researcher should be cautious to use N implanted layer as an inter-layer for increasing CoCrMo alloy load carrying capacity in vivo environment.

Soft Magnetic Properties of Nanocrystalline Fe-M-(B and/or O)(M=Group IV A, V A Elements) Alloy Films

OpenAIRE

Hayakawa, Y.; Makino, A.; Inoue, A.; Masumoto, T.

1996-01-01

In Fe-M-(B and/or O)(M=group IV A, V A elements) alloy films, nanocrystalline bcc phase are formed by annealing the amorphous single phase for Fe-M-B films, whereas the bcc nanocrystals are already formed in an as-deposited state for Fe-M-O or Fe-M-B-O) films. Among Fe-M-B films with various M elements, Fe-(Zr, Hf, Nb, Ta)-B alloy films exhibit high saturation magnetization (Is) above 1.4 T and high relative permeability (|μ|) above 1000 at 1MHz. The highest |μ| of 3460 at 1MHz is obtained fo...

Sample preparation and study by electronic diffraction of oxidations and fluorinations of some metals and alloys

International Nuclear Information System (INIS)

Auguin, B.

1963-06-01

After having recalled that electron diffraction is particularly adapted to the study of thin films and surface layers, notably those forming during corrosions, and recalled some characteristics of this technique (wavelength, interactions with substances, parasite reactions, observation by transmission or reflection, obtained diagrams for polycrystalline and mono-crystalline substances), the author describes how samples are prepared in the case of examinations performed by transmission and by reflection. As fluorination agents are used for the separation of uranium 235 and 238, the second part discusses some works related to the fluorination of metals and alloys, some of them being used in these separation installations. Chlorine trifluoride is generally used and materials are generally oxidised. Thus, the author reports the study of the action of ClF 3 on different oxides. Oxidations of iron, nickel and Monel are addressed, as well as the behaviour of stainless steel. The study of fluorinations of metals (nickel, chromium, copper), alloys (stainless steel, Monel) and oxides is reported. The author finally addresses treatments performed after fluorinations: vacuum heating, action of humid air

Electrochemical deposition of Mg(OH)2/GO composite films for corrosion protection of magnesium alloys

OpenAIRE

Fengxia Wu; Jun Liang; Weixue Li

2015-01-01

Mg(OH)2/graphene oxide (GO) composite film was electrochemical deposited on AZ91D magnesium alloys at constant potential. The characteristics of the Mg(OH)2/GO composite film were investigated by scanning electron microscope (SEM), energy-dispersive X-ray spectrometry (EDS), X-ray diffractometer (XRD) and Raman spectroscopy. It was shown that the flaky GO randomly distributed in the composite film. Compared with the Mg(OH)2 film, the Mg(OH)2/GO composite film exhibited more uniform and compac...

Synthesis and application of a novel Cu/RGO@Pb alloy for lead-acid batteries

International Nuclear Information System (INIS)

Wu, Yumeng; Zhao, Ruirui; Zhou, Huawen; Zhang, Dejing; Zhao, Wei; Chen, Hongyu

2016-01-01

In this work, a novel Cu/RGO@Pb alloy was prepared successfully and tested in the simulated lead-acid battery environment. In preparing the novel alloy, Cu/RGO composite was firstly synthesized in order to increase the wettability of RGO to Pb, and then the composite was added to the molten lead to obtain the target alloy. Scanning electron microscope, energy dispersive spectrometer, X-ray diffraction as well as electrochemical measurements were employed to evaluate the performance of the obtained composite and alloy. Results show that the prepared Cu/RGO@Pb possessed higher oxygen evolution over-potential and lower hydrogen evolution over-potential than the contrast alloy, indicating this novel alloy was more suitable for using as positive grids in lead acid batteries. Moreover, the RGO additive could inhibit the formation of Pb(II) and Pb(IV) film on the surface of the alloy, which could enhance the deep-charge/discharge performance of the grids and improve the corrosion resistance.

Surface Properties of a Novel Poly(vinyl alcohol Film Prepared by Heterogeneous Saponification of Poly(vinyl acetate Film

Directory of Open Access Journals (Sweden)

Seong Baek Yang

2017-10-01

Full Text Available Almost general poly(vinyl alcohol (PVA films were prepared by the processing of a PVA solution. For the first time, a novel poly(vinyl alcohol (PVA film was prepared by the saponification of a poly(vinyl acetate (PVAc film in a heterogenous medium. Under the same saponification conditions, the influence of saponification time on the degree of saponification (DS was studied for the preparation of the saponified PVA film, and it was found that the DS varied with time. Optical microscopy was used to confirm the characteristics and surface morphology of the saponified PVA film, revealing unusual black globules in the film structure. The contact angle of the films was measured to study the surface properties, and the results showed that the saponified PVA film had a higher contact angle than the general PVA film. To confirm the transformation of the PVAc film to the PVA film, 1H nuclear magnetic resonance spectroscopy, X-ray diffraction measurements, differential scanning calorimetry, and Fourier-transform infrared spectroscopy were employed.

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.

Magnetic hysteresis properties of melt-spun Nd-Fe-B alloys prepared by centrifugal method

International Nuclear Information System (INIS)

Andreev, S.V.; Kudrevatykh, N.V.; Pushkarsky, V.I.; Markin, P.E.; Zaikov, N.K.; Tarasov, E.N.

1998-01-01

Magnetic hysteresis properties and microstructure peculiarities of melt spun Nd-Fe-B alloys (ribbons) prepared by melt quenching onto the internal surface of an iron spinning wheel at tangential speeds in the range 5-20 m/s are reported. The alloy composition was Nd-36% wt, B-1.2% wt. and Fe-remainder. It was found that the coercivity of ribbons does not practically depend on the wheel speed in applied range (18 kOe at 5 m/s and 22 kOe at 20 m/s), whereas the grain size of the basic phase (2-14-1) ste[ily decreases when the speed rises, starting from 2-3 μm for 5 m/s alloy down to the 200-300 nm for 20 m/s alloy. All ribbons have normal convex demagnetization curves, even those prepared at low wheel speeds (without peculiar step near H∝0, which usually exists on such curves for tr[itionally prepared underquenched melt-spun Nd-Fe-B alloys). Grinding the ribbon in a vibration mill causes the coercivity drop to 7 kOe after 120 min of treatment. However, this operation increases the powder alignment ability and, as a result, the energy product for a fully dense magnet from anisotropic powder prepared from some ribbons rises to 20-23 MGOe. (orig.)

Preparation and characterization of highly L21-ordered full-Heusler alloy Co2FeAl0.5Si0.5 thin films for spintronics device applications

International Nuclear Information System (INIS)

Wang Wenhong; Sukegawa, Hiroaki; Shan Rong; Furubayashi, Takao; Inomata, Koichiro

2008-01-01

We report the investigation of structure and magnetic properties of full-Heusler alloy Co 2 FeAl 0.5 Si 0.5 (CFAS) thin films grown on MgO-buffered MgO (001) substrates through magnetron sputtering. It was found that single-crystal CFAS thin films with high degree of L2 1 ordering and sufficiently flat surface could be obtained after postdeposition annealing. All the films show a distinct uniaxial magnetic anisotropy with the easy axis of magnetization along the in-plane [110] direction. These results indicate that the use of the MgO buffer for CFAS is a promising approach for achieving a higher tunnel magnetoresistance ratio, and thus for spintronics device applications

Preparation of high-pressure phase boron nitride films by physical vapor deposition

CERN Document Server

Zhu, P W; Zhao, Y N; Li, D M; Liu, H W; Zou Guang Tian

2002-01-01

The high-pressure phases boron nitride films together with cubic, wurtzic, and explosive high-pressure phases, were successfully deposited on the metal alloy substrates by tuned substrate radio frequency magnetron sputtering. The percentage of cubic boron nitride phase in the film was about 50% as calculated by Fourier transform infrared measurements. Infrared peak position of cubic boron nitride at 1006.3 cm sup - sup 1 , which is close to the stressless state, indicates that the film has very low internal stress. Transition electron microscope micrograph shows that pure cubic boron nitride phase exits on the surface of the film. The growth mechanism of the BN films was also discussed.

The electrochemical properties and mechanism of formation of anodic oxide films on Mg-Al alloys

International Nuclear Information System (INIS)

Kim, Seong Jong; Okido, Masazumi

2003-01-01

The electronchemical properties and the mechanism of formation of anodic oxide films on Mg alloys containing 0-15 mass% Al, when anodized in NaOH solution, were investigated by focusing on the effects of anodizing potential, Al content, and anodizing time. The intensity ratio of Mg(OH) 2 in the XRD analysis decreased with increasing applied potential, while that of MgO increased. Mg(OH) 2 was barely detected at 80 V, while MgO was readily detected. The anti-corrosion properties of anodized specimens at each constant potential were better than those of non-anodized specimens. The specimen anodized at an applied potential of 3 V had the best anti-corrosion property. The intensity ratio of the β phase increased with aluminum content in Mg-Al alloys. During anodizing, the active dissolution reaction occurred preferentially in β phase until about 4 min, and then the current density increased gradually until 7 min. The dissolution reaction progressed in α phase, which had a lower Al content. In the anodic polarization test in 0.017 mol·dm -3 NaCl and 0.1 mol·dm -3 Na 2 SO 4 at 298 K, the current density of Mg-15 mass% Al alloy anodized for 10 min increased, since the anodic film that forms on the α phase is a non-compacted film. The anodic film on the α phase at 30 min was a compact film as compared with that at 10 min

Multifold Seebeck increase in RuO2 films by quantum-guided lanthanide dilute alloying

International Nuclear Information System (INIS)

Music, Denis; Basse, Felix H.-U.; Schneider, Jochen M.; Han, Liang; Borca-Tasciuc, Theo; Devender; Gengler, Jamie J.; Voevodin, Andrey A.; Ramanath, Ganpati

2014-01-01

Ab initio predictions indicating that alloying RuO 2 with La, Eu, or Lu can increase the Seebeck coefficient α manifold due to quantum confinement effects are validated in sputter-deposited La-alloyed RuO 2 films showing fourfold α increase. Combinatorial screening reveals that α enhancement correlates with La-induced lattice distortion, which also decreases the thermal conductivity twentyfold, conducive for high thermoelectric figures of merit. These insights should facilitate the rational design of high efficiency oxide-based thermoelectrics through quantum-guided alloying

A Homogenized Free Energy Model for Hysteresis in Thin-film Shape Memory Alloys

National Research Council Canada - National Science Library

Massad, Jordan E; Smith, Ralph C

2004-01-01

Thin-film shape memory alloys (SMAs) have become excellent candidates for microactuator fabrication in MEMS due to their capability to achieve very high work densities, produce large deformations, and generate high stresses...

Appropriate materials and preparation techniques for polycrystalline-thin-film thermophotovoltaic cells

Science.gov (United States)

Dhere, Neelkanth G.

1997-03-01

Polycrystalline-thin-film thermophotovoltaic (TPV) cells have excellent potential for reducing the cost of TPV generators so as to address the hitherto inaccessible and highly competitive markets such as self-powered gas-fired residential warm air furnaces and energy-efficient electric cars, etc. Recent progress in polycrystalline-thin-film solar cells have made it possible to satisfy the diffusion length and intrinsic junction rectification criteria for TPV cells operating at high fluences. Continuous ranges of direct bandgaps of the ternary and pseudoternary compounds such as Hg1-xCdxTe, Pb1-xCdxTe, Hg1-xZnxTe, and Pb1-xZnxS cover the region of interest of 0.50-0.75 eV for efficient TPV conversion. Other ternary and pseudoternary compounds which show direct bandgaps in most of or all of the 0.50-0.75 eV range are Pb1-xZnxTe, Sn1-xCd2xTe2, Pb1-xCdxSe, Pb1-xZnxSe, and Pb1-xCdxS. Hg1-xCdxTe (with x~0.21) has been studied extensively for infrared detectors. PbTe and Pb1-xSnxTe have also been studied for infrared detectors. Not much work has been carried out on Hg1-xZnxTe thin films. Hg1-xCdxTe and Pb1-xCdxTe alloys cover a wide range of cut-off wavelengths from the far infrared to the near visible. Acceptors and donors are introduced in these materials by excess non-metal (Te) and excess metal (Hg and Pb) respectively. Extrinsic acceptor impurities are Cu, Au, and As while and In and Al are donor impurities. Hg1-xCdxTe thin films have been deposited by isothermal vapor-phase epitaxy (VPE), liquid phase epitaxy (LPE), hot-wall metalorganic chemical vapor deposition (MOCVD), electrodeposition, sputtering, molecular beam epitaxy (MBE), laser-assisted evaporation, and vacuum evaporation with or without hot-wall enclosure. The challenge in the preparation of Hg1-xCdxTe is to provide excess mercury incidence rate, to optimize the deposition parameters for enhanced mercury incorporation, and to achieve the requisite stoichiometry, grain size, and doping. MBE and MOCVD

Characterising palladium-silver and palladium-nickel alloy membranes using SEM, XRD and PIXE

International Nuclear Information System (INIS)

Keuler, J.N.; Lorenzen, L.; Sanderson, R.D.; Prozesky, V.; Przybylowicz, W.J.

1999-01-01

Palladium alloy membranes were prepared by successive electroless plating steps on an alumina-zirconia support membrane. Palladium, silver and nickel were deposited in layers and then the metal films were heat treated for 5 h in a hydrogen atmosphere at 650 deg. C. The topography of the metal coatings and cross-sections of the films (before and after heating) were characterised using scanning electron microscopy (SEM). XRD was used to determine the crystal phase of the alloy coatings. Both SEM and XRD provide only surface information and therefore micro-PIXE was used to extract depth information of the alloy coating. Concentration profiles across the thickness of the films were constructed to determine penetration of the coating into the support membrane pores during electroless plating and to investigate diffusion of coated layers during the heating step

The electroplated Pd–Co alloy film on 316 L stainless steel and the corrosion resistance in boiling acetic acid and formic acid mixture with stirring

Energy Technology Data Exchange (ETDEWEB)

Li, Sirui; Zuo, Yu, E-mail: zuoy@mail.buct.edu.cn; Tang, Yuming; Zhao, Xuhui

2014-12-01

Highlights: • Pd–Co alloy films were deposited on 316 L stainless steel by electroplating. • The Pd–Co films show fine grain size, low porosity and obviously high hardness. • In strong acids with Br{sup −} and stirring, Pd–Co films show good corrosion resistance. • The high hardness of Pd–Co film retards the development of micro-pores in the film. - Abstract: Pd–Co alloy films were deposited on 316 L stainless steel by electroplating. Scanning electronic microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, weight loss test and polarization test were used to determine the properties of the Pd–Co alloy films. The Pd–Co films show fine grain size, low porosity and obviously high micro-hardness. The Co content in the film can be controlled in a large range from 21.9 at.% to 57.42 at.%. Pd is rich on the Pd–Co film surface, which is benefit to increase the corrosion resistance. In boiling 90% acetic acid plus 10% formic acid mixture with 0.005 M Br{sup −} under stirring, the Pd–Co plated stainless steel samples exhibit evidently better corrosion resistance in contrast to Pd plated samples. The good corrosion resistance of the Pd–Co alloy film is explained by the better compactness, the lower porosity, and the obviously higher micro-hardness of the alloy films, which increases the resistance to erosion and retards the development of micro-pores in the film.

Surface preparation for the heteroepitactic growth of ceramic thin films

International Nuclear Information System (INIS)

Norton, M.G.; Summerfelt, S.R.; Carter, C.B.

1990-01-01

The morphology, composition, and crystallographic orientation of the substrate influence the nucleation and growth of deposited thin films. A method for the preparation of controlled, characteristic surfaces is reported. The surfaces are suitable for the heteroepitactic growth of thin films. When used in the formation of electron-transparent thin foils, the substrates can be used to investigate the very early stages of film growth using transmission electron microscopy. The substrate preparation involves the cleaning and subsequent annealing to generate a surface consisting of a series of steps. The step terraces are formed on the energetically stable surface, and controlled nucleation and growth of films at step edges is found. The substrate materials prepared using this technique include (001) MgO, (001) SrTiO 3 , and (001) LaAlO 3

In vitro corrosion behavior of Ti-O film deposited on fluoride-treated Mg-Zn-Y-Nd alloy

Energy Technology Data Exchange (ETDEWEB)

Hou, S.S.; Zhang, R.R. [Materials Research Center, School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450002 (China); Guan, S.K., E-mail: skguan@zzu.edu.cn [Materials Research Center, School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450002 (China); Ren, C.X.; Gao, J.H.; Lu, Q.B.; Cui, X.Z. [Materials Research Center, School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450002 (China)

2012-02-01

In this paper, a new composite coating was fabricated on magnesium alloy by a two-step approach, to improve the corrosion resistance and biocompatibility of Mg-Zn-Y-Nd alloy. First, fluoride conversion layer was synthesized on magnesium alloy surface by immersion treatment in hydrofluoric acid and then, Ti-O film was deposited on the preceding fluoride layer by magnetron sputtering. FE-SEM images revealed a smooth and uniform surface consisting of aggregated nano-particles with average size of 100 nm, and a total coating thickness of {approx}1.5 {mu}m, including an outer Ti-O film of {approx}250 nm. The surface EDS and XRD data indicated that the composite coating was mainly composed of crystalline magnesium fluoride (MgF{sub 2}), and non-crystalline Ti-O. Potentiodynamic polarization tests revealed that the composite coated sample have a corrosion potential (E{sub corr}) of -1.60 V and a corrosion current density (I{sub corr}) of 0.17 {mu}A/cm{sup 2}, which improved by 100 mV and reduced by two orders of magnitude, compared with the sample only coated by Ti-O. EIS results showed a polarization resistance of 3.98 k{Omega} cm{sup 2} for the Ti-O coated sample and 0.42 k{Omega} cm{sup 2} for the composite coated sample, giving an improvement of about 100 times. After 72 h immersion in SBF, widespread damage and deep corrosion holes were observed on the Ti-O coated sample surface, while the integrity of composite coating remained well after 7 d. In brief, the data suggested that single Ti-O film on degradable magnesium alloys was apt to become failure prematurely in corrosion environment. Ti-O film deposited on fluoride-treated magnesium alloys might potentially meet the requirements for future clinical magnesium alloy stent application.

In vitro corrosion behavior of Ti-O film deposited on fluoride-treated Mg-Zn-Y-Nd alloy

International Nuclear Information System (INIS)

Hou, S.S.; Zhang, R.R.; Guan, S.K.; Ren, C.X.; Gao, J.H.; Lu, Q.B.; Cui, X.Z.

2012-01-01

In this paper, a new composite coating was fabricated on magnesium alloy by a two-step approach, to improve the corrosion resistance and biocompatibility of Mg-Zn-Y-Nd alloy. First, fluoride conversion layer was synthesized on magnesium alloy surface by immersion treatment in hydrofluoric acid and then, Ti-O film was deposited on the preceding fluoride layer by magnetron sputtering. FE-SEM images revealed a smooth and uniform surface consisting of aggregated nano-particles with average size of 100 nm, and a total coating thickness of ∼1.5 μm, including an outer Ti-O film of ∼250 nm. The surface EDS and XRD data indicated that the composite coating was mainly composed of crystalline magnesium fluoride (MgF 2 ), and non-crystalline Ti-O. Potentiodynamic polarization tests revealed that the composite coated sample have a corrosion potential (E corr ) of -1.60 V and a corrosion current density (I corr ) of 0.17 μA/cm 2 , which improved by 100 mV and reduced by two orders of magnitude, compared with the sample only coated by Ti-O. EIS results showed a polarization resistance of 3.98 kΩ cm 2 for the Ti-O coated sample and 0.42 kΩ cm 2 for the composite coated sample, giving an improvement of about 100 times. After 72 h immersion in SBF, widespread damage and deep corrosion holes were observed on the Ti-O coated sample surface, while the integrity of composite coating remained well after 7 d. In brief, the data suggested that single Ti-O film on degradable magnesium alloys was apt to become failure prematurely in corrosion environment. Ti-O film deposited on fluoride-treated magnesium alloys might potentially meet the requirements for future clinical magnesium alloy stent application.

Preparation and Properties of Mg-Cu-Y-Al bulk Amorphous Alloys

DEFF Research Database (Denmark)

Pryds, Nini; Eldrup, Morten Mostgaard; Ohnuma, M.

2000-01-01

Bulk amorphous (Mg(1-gamma)Al(gamma))(60)CU(30)Y(10) alloys were prepared using a relatively simple technique of rapid cooling of the melt in a copper wedge mould. The temperature vs, time was recorded during the cooling and solidification process of the melt and compared with a spacial and tempo......Bulk amorphous (Mg(1-gamma)Al(gamma))(60)CU(30)Y(10) alloys were prepared using a relatively simple technique of rapid cooling of the melt in a copper wedge mould. The temperature vs, time was recorded during the cooling and solidification process of the melt and compared with a spacial...... temperatures in specimens containing a few percent Al. The alloy with no Al crystallises apparently without the formation of nanoparticles. The critical cooling rate for the formation of an amorphous Mg(60)CU(30)Y(10) specimen was determined experimentally by a combination of DSC data and temperature vs, time...

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...

The Magnetic Properties of Metal-Alloy Glass Composites Prepared by Ion Implantation

International Nuclear Information System (INIS)

Julian Fernandez, Cesar de; Mattei, Giovanni; Sada, Cinzia; Maurizio, Chiara; Padovani, Sara; Mazzoldi, Paolo; Sangregorio, Claudio; Gatteschi, Dante

2003-01-01

The structural and magnetic properties of Co-Ni, Co-Fe and Ni-Cu alloy nanoparticles formed in silica matrix by sequential ion implantation are presented. These nanoparticles show crystal structure similar to the corresponding bulk alloys. In the Co-Ni and Co-Fe, magnetization saturation and coercive field depend on the the alloy composition, crystal structure and size effects. Ferromagnetic resonance studies show that collective magnetic processes are present and these are determined by the film-like morphology of the implanted region. The temperature dependence of the magnetization of the NixCu100-x samples indicates that their Curie Temperatures are larger than the corresponding bulk ones. This feature is discussed considering the composition of the nanoparticles and the size effects

Alloy formation during the electrochemical growth of a Ag-Cd ultrathin film on Au(1 1 1)

International Nuclear Information System (INIS)

Barrio, M.C. del; Garcia, S.G.; Salinas, D.R.

2009-01-01

The electrodeposition of a Ag/Cd ultrathin film on a Au(1 1 1) surface and the formation of a surface alloy during this process have been studied using classical electrochemical techniques and in situ Scanning Tunneling Microscopy (STM). The films were obtained from separate electrolytes containing Ag + or Cd 2+ ions and from a multicomponent solution containing both ions. First, the polarization conditions were adjusted in order to form a Ag film by overpotential deposition. Afterwards, a Cd monolayer was formed onto this Au(1 1 1)/Ag modified surface by underpotential deposition. The voltammetric behavior of the Cd UPD and the in situ STM images indicated that the ultrathin Ag films were uniformly deposited and epitaxially oriented with respect to the Au(1 1 1) surface. Long time polarization experiments showed that a significant Ag-Cd surface alloying accompanied the formation of the Cd monolayer on the Au(1 1 1)/Ag modified surface, independent of the Ag film thickness. In the case of an extremely thin Ag layer (1 Ag ML) the STM images and long time polarization experiments revealed a solid state diffusion process of Cd, Ag, and Au atoms which can be responsible for the formation of different Ag-Cd or Au-Ag-Cd alloy phases.

Characterization of film-forming solutions and films incorporating free and nanoencapsulated tea polyphenol prepared by gelatins with different Bloom values

Science.gov (United States)

Gelatin film-forming solutions and their films incorporating tea polyphenol (TP) and chitosan nanoparticles (CSNs) were prepared from gelatins with different Bloom values (100, 150 and 225). Blank gelatin film-forming solutions and films were prepared as controls. Gelatins with higher Bloom values h...

Effect of the chemistry and structure of the native oxide surface film on the corrosion properties of commercial AZ31 and AZ61 alloys

Energy Technology Data Exchange (ETDEWEB)

Feliu, Sebastian, E-mail: sfeliu@cenim.csic.es [Centro Nacional de Investigaciones Metalurgicas CSIC, Avda. Gregorio del Amo 8, 28040 Madrid (Spain); Maffiotte, C. [CIEMAT-DT edificio 30, Avda. Complutense, 22, 28040 Madrid (Spain); Samaniego, A.; Galvan, Juan Carlos [Centro Nacional de Investigaciones Metalurgicas CSIC, Avda. Gregorio del Amo 8, 28040 Madrid (Spain); Barranco, Violeta [Centro Nacional de Investigaciones Metalurgicas CSIC, Avda. Gregorio del Amo 8, 28040 Madrid (Spain); Instituto de Ciencias de Materiales de Madrid, ICMM, Consejo Superior de Investigaciones Cientificas, CSIC, Sor Juana Ines de la Cruz, 3, Cantoblanco, 28049, Madrid (Spain)

2011-08-01

The purpose of this study has been to advance in knowledge of the chemical composition, structure and thickness of the thin native oxide film formed spontaneously in contact with the laboratory atmosphere on the surface of freshly polished commercial AZ31 and AZ61 alloys with a view to furthering the understanding of protection mechanisms. For comparative purposes, and to more fully describe the behaviour of the native oxide film, the external oxide films formed as a result of the manufacturing process (as-received condition) have been characterised. The technique applied in this research to study the thin oxide films (thickness of just a few nanometres) present on the surface of the alloys has basically been XPS (X-ray photoelectron spectroscopy) in combination with ion sputtering. Corrosion properties of the alloys were studied in 0.6 M NaCl by measuring charge transfer resistance values, which are deduced from EIS (electrochemical impedance spectroscopy) measurements after 1 h of exposure. Alloy AZ61 generally showed better corrosion resistance than AZ31, and the freshly polished alloys showed better corrosion resistance than the alloys in as-received condition. This is attributed to a combination of (1) higher thickness of the native oxide film on the AZ61 alloy and (2) greater uniformity of the oxide film in the polished condition. The formation of an additional oxide layer composed by a mixture of spinel (MgAl{sub 2}O{sub 4}) and MgO seems to diminish the protective properties of the passive layer on the surface of the alloys in as-received condition.

Effect of the chemistry and structure of the native oxide surface film on the corrosion properties of commercial AZ31 and AZ61 alloys

International Nuclear Information System (INIS)

Feliu, Sebastian; Maffiotte, C.; Samaniego, A.; Galvan, Juan Carlos; Barranco, Violeta

2011-01-01

The purpose of this study has been to advance in knowledge of the chemical composition, structure and thickness of the thin native oxide film formed spontaneously in contact with the laboratory atmosphere on the surface of freshly polished commercial AZ31 and AZ61 alloys with a view to furthering the understanding of protection mechanisms. For comparative purposes, and to more fully describe the behaviour of the native oxide film, the external oxide films formed as a result of the manufacturing process (as-received condition) have been characterised. The technique applied in this research to study the thin oxide films (thickness of just a few nanometres) present on the surface of the alloys has basically been XPS (X-ray photoelectron spectroscopy) in combination with ion sputtering. Corrosion properties of the alloys were studied in 0.6 M NaCl by measuring charge transfer resistance values, which are deduced from EIS (electrochemical impedance spectroscopy) measurements after 1 h of exposure. Alloy AZ61 generally showed better corrosion resistance than AZ31, and the freshly polished alloys showed better corrosion resistance than the alloys in as-received condition. This is attributed to a combination of (1) higher thickness of the native oxide film on the AZ61 alloy and (2) greater uniformity of the oxide film in the polished condition. The formation of an additional oxide layer composed by a mixture of spinel (MgAl 2 O 4 ) and MgO seems to diminish the protective properties of the passive layer on the surface of the alloys in as-received condition.

Manipulating magnetic anisotropy of the ultrathin Co2FeAl full-Heusler alloy film via growth orientation of the Pt buffer layer

International Nuclear Information System (INIS)

Wen, F.S.; Xiang, J.Y.; Hao, C.X.; Zhang, F.; Lv, Y.F.; Wang, W.H.; Hu, W.T.; Liu, Z.Y.

2013-01-01

The ultrathin films of Co 2 FeAl (CFA) full-Heusler alloy were prepared between two Pt layers on MgO single crystals by magnetron sputtering. By controlling the substrate temperature, different growth orientations of the Pt underlayers were realized, and their effects were investigated on the magnetic anisotropy of the ultrathin CFA film. It was revealed that different Pt orientations lead to distinctly different magnetic anisotropy for the sandwiched ultrathin CFA films. The Pt (111) orientation favors the perpendicular anisotropy, while the appearance of partial Pt (001) orientation leads to the quick decrease of perpendicular anisotropy and the complete Pt (001) orientation gives rise to the in-plane anisotropy. With the Pt (111) orientation, the temperature and thickness-induced spin reorientation transitions were investigated in the sandwiched ultrathin CFA films. - Highlights: • Different Pt orientations lead to different magnetic anisotropy for sandwiched ultrathin CFA films. • The Pt (111) orientation favors the perpendicular anisotropy for CFA layer. • Temperature and thickness-induced spin reorientation transitions were investigated in sandwiched ultrathin CFA films. • 0.8 nm CFA film is good candidate as electrode in magnetic tunnel junctions

Investigation of corrosion and analysis of passive films concerning some nickel alloys and stainless steels in reconstructed geological environments

International Nuclear Information System (INIS)

Jallerat, Nelly

1984-01-01

This research thesis addresses the corrosion behaviour of materials which might be used for the fabrication of radioactive waste containers. After a bibliographical study on films formed on Fe-Cr-Ni alloys, this research concentrates on passivation and de-passivation phenomena of three nickel-base alloys among the most resistant to corrosion and which also meet processing and economic criteria: Hastelloy C4, Inconel 625 and ZICNDU 25-20. Titanium and Ti-Pd alloy are also studied. Parameters governing pitting corrosion are notably studied. After a recall of knowledge on passive films formed on Fe-Cr-Ni alloys, and a presentation of experimental and technical conditions, the author reports and discussed the results obtained by electrochemical studies, reports the determination of factors governing alloy passivation in geological waters. The influence of some soluble impurities is notably studied. The author reports the analysis by glow discharge optical emission spectrometry to determine the composition of passive films with respect to geological water nature, the immersion duration and the electrode potential. Additional surface analyses are performed by X-ray photoelectron spectrometry (XPS or ESCA) and secondary ion mass spectrometry (SIMS). Finally, the author uses a dosing method by neutron radio-activation of alloy elements to determine dissolution mechanisms [fr

Preparation and characterization of vanadium oxide thin films

Energy Technology Data Exchange (ETDEWEB)

Monfort, O.; Plesch, G. [Comenius University of Bratislava, Faculty of Natural Sciences, Department of Inorganic Chemistry, 84215 Bratislava (Slovakia); Roch, T. [Comenius University of Bratislava, Faculty of Mathematics Physics and Informatics, Department of Experimental Physics, 84248 Bratislava (Slovakia)

2013-04-16

The thermotropic VO{sub 2} films have many applications, since they exhibit semiconductor-conductor switching properties at temperature around 70 grad C. Vanadium oxide thin films were prepared via sol-gel method. Spin coater was used to depose these films on Si/SiO{sub 2} and lime glass substrates. Thin films of V{sub 2}O{sub 5} can be reduced to metastable VO{sub 2} thin films at the temperature of 450 grad C under the pressure of 10{sup -2} Pa. These films are then converted to thermotropic VO{sub 2} at 700 grad C in argon under normal pressure. (authors)

Magnetostrictive thin films prepared by RF sputtering

International Nuclear Information System (INIS)

Carabias, I.; Martinez, A.; Garcia, M.A.; Pina, E.; Gonzalez, J.M.; Hernando, A.; Crespo, P.

2005-01-01

Fe 80 B 20 thin films have been prepared by ion beam sputtering magnetron on room temperature. The films were fabricated on different substrates to compare the different magnetic and structural properties. In particular the growth of films on flexible substrates (PDMS, Kapton) has been studied to allow a simple integration of the system in miniaturized magnetostrictive devices. X-ray diffraction patterns indicate that films are mainly amorphous although the presence of some Fe nanoparticles cannot be ruled out. The coercive field of thin films ranges between 15 and 35 Oe, depending on substrate. Magnetostriction measurements indicate the strong dependence of the saturation magnetostriction with the substrate. Samples on flexible substrates exhibit a better performance than samples deposited onto glass substrates

Mechanical, structural and thermal properties of Ag-Cu and ZnO reinforced polylactide nanocomposite films.

Science.gov (United States)

Ahmed, Jasim; Arfat, Yasir Ali; Castro-Aguirre, Edgar; Auras, Rafael

2016-05-01

Plasticized polylactic acid (PLA) based nanocomposite films were prepared by incorporating polyethylene glycol (PEG) and two selected nanoparticles (NPs) [silver-copper (Ag-Cu) alloy (film matrix. Copyright © 2016 Elsevier B.V. All rights reserved.

Free-standing graphene films prepared via foam film method for great capacitive flexible supercapacitors

Science.gov (United States)

Zhu, Yucan; Ye, Xingke; Tang, Zhonghua; Wan, Zhongquan; Jia, Chunyang

2017-11-01

Recently, graphene films have always attracted attention due to their excellent characteristics in energy storage. In this work, a novel graphene oxide (GO) film with excellent mechanical properties, whose thickness was regulated simply via changing the concentration of the surfactant, was successfully prepared by foam film method. After chemical reduction, the reduced GO (rGO) films have excellent electrical conductivity of ∼172 S cm-1. Moreover, the supercapacitors based on the rGO films exhibit satisfied capacitive performance of ∼56 mF cm-2 at 0.2 mA cm-2 in 6 M KOH aqueous solution. Meanwhile, the flexible all solid state supercapacitors (FSSCs) based on the rGO films also show great volumetric capacitance of ∼2810 mF cm-3 at 12 mA cm-3 (∼1607 mF cm-3 at 613 mA cm-3) with polyvinyl alcohol-KOH gel electrolyte. Besides, after 10000 cycles and continuously bent to 180° for 300 times, the volumetric capacitance of the FSSC remains at 81.4% and 90.4% of its initial capacitance value, respectively. Therefore, the free-standing rGO films prepared via foam film method could be considered as promising electrode materials for high performance flexible supercapacitors.

Preparation, Characterization, and Electrochromic Properties of Nanocellulose-Based Polyaniline Nanocomposite Films.

Science.gov (United States)

Zhang, Sihang; Sun, Gang; He, Yongfeng; Fu, Runfang; Gu, Yingchun; Chen, Sheng

2017-05-17

On the basis of nanocellulose obtained by acidic swelling and ultrasonication, rodlike nanocellulose/polyaniline nanocomposites with a core-shell structure have been prepared via in situ polymerization. Compared to pure polyaniline, the nanocomposites show superior film-forming properties, and the prepared nanocomposite films demonstrate excellent electrochemical and electrochromic properties in electrolyte solution. Nanocomposite films, especially the one prepared with 40% polyaniline coated nanocomposite, exhibited faster response time (1.5 s for bleaching and 1.0 s for coloring), higher optical contrast (62.9%), higher coloration efficiency (206.2 cm 2 /C), and more remarkable switching stability (over 500 cycles). These novel nanocellulose-based nanorod network films are promising novel electrochromic materials with excellent properties.

Magnetic properties of centrifugally prepared melt-spun Nd-Fe-B alloys and their powders

International Nuclear Information System (INIS)

Andreev, S.V.; Kudrevatykh, N.V.; Kozlov, A.I.; Markin, P.E.; Pushkarskiy, V.I.

1998-01-01

Magnetic hysteresis properties and microstructure peculiarities of melt spun Nd-Fe-B alloys (ribbons) prepared by melt quenching on to the internal surface of an iron spinning wheel at the tangential speeds in the range 5-20 m/sec are reported. The alloy composition was Nd-36% wt. B-1.2% wt. and Fe-reminder. It was found that the coercivity of ribbons does not practically depend on the wheel speed in the applied range (1430 kA/m at 5 m/sec and 1750 kA/m at 20 m/sec), whereas the grain size of the basic phase (2-14-1) steadily decreases when the speed rises, starting from 2-3 μm for 5 m sec alloy down to the 200-300 nm for 20 m/sec alloy. All ribbons have normal convex demagnetization curves, even those prepared at low wheel speeds (without peculiar step near H∝0, which usually exists on such curves for traditionally prepared underquenched melt-spun Nd-Fe-B alloys). Grinding the ribbons subjected to hydrogen and annealing treatments causes the coercivity drop. However, this operations increase the powder alignment ability and, as a result, the energy product for fully dense magnet from such powder rises to 160-180 kJ/m 3 . (orig.)

The electrochemical properties and mechanism of formation of anodic oxide films on Mg-Al alloys

Energy Technology Data Exchange (ETDEWEB)

Kim, Seong Jong; Okido, Masazumi [Nagoya Univ., Nagoya (Japan)

2003-07-01

The electronchemical properties and the mechanism of formation of anodic oxide films on Mg alloys containing 0-15 mass% Al, when anodized in NaOH solution, were investigated by focusing on the effects of anodizing potential, Al content, and anodizing time. The intensity ratio of Mg(OH){sub 2} in the XRD analysis decreased with increasing applied potential, while that of MgO increased. Mg(OH){sub 2} was barely detected at 80 V, while MgO was readily detected. The anti-corrosion properties of anodized specimens at each constant potential were better than those of non-anodized specimens. The specimen anodized at an applied potential of 3 V had the best anti-corrosion property. The intensity ratio of the {beta} phase increased with aluminum content in Mg-Al alloys. During anodizing, the active dissolution reaction occurred preferentially in {beta} phase until about 4 min, and then the current density increased gradually until 7 min. The dissolution reaction progressed in {alpha} phase, which had a lower Al content. In the anodic polarization test in 0.017 mol{center_dot}dm{sup -3} NaCl and 0.1 mol{center_dot}dm{sup -3} Na{sub 2}SO{sub 4} at 298 K, the current density of Mg-15 mass% Al alloy anodized for 10 min increased, since the anodic film that forms on the {alpha} phase is a non-compacted film. The anodic film on the {alpha} phase at 30 min was a compact film as compared with that at 10 min.

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.

Effect of assembled time on the corrosion behaviors of SAMs film on the AM60B alloy and its assembled mechanism

Energy Technology Data Exchange (ETDEWEB)

Liu, Xianbin, E-mail: xbliu@imr.ac.cn; Shan, Dayong; Song, Yingwei; Han, En-hou

2015-01-15

The influence of assembled time on the corrosion behaviors of SAMs film on the AM60B alloy and its assembled mechanism have been investigated by electrochemical measurements, scanning electron microscopy (SEM) observation and X-ray photoelectron spectroscopy (XPS) analysis. The self-assembled experiment on the AM60B magnesium alloy indicates that the corrosion susceptibility decreases with increasing assembled time until 24 h on cast AM60B alloy and then increases with increase of the assembled time proved by EIS measurement and potentiodynamic curves. The self-assembled experiments on pure magnesium and various heat treated cast AM60B magnesium alloy illuminate that the dissolved aluminum in magnesium solid solution is the key factor for assembled efficiency and is hard to self-assemble on the pure magnesium without aluminum. The corrosion resistance of self-assembled film on AM60B magnesium alloy is monotonically increasing with the dissolved aluminum. The results of XPS analysis reveal the assembled mechanism on AM60B and corroborate the function of Al element. - Highlights: • It is hard to self-assemble on the pure magnesium. • 24 h assembled film has the low corrosion susceptibility by EIS and polarization. • The corrosion susceptibility of SAMs film lie on the Al atom state in AM60B. • The corrosion susceptibility of SAMs film is decreasing with the dissolved Al.

Effect of assembled time on the corrosion behaviors of SAMs film on the AM60B alloy and its assembled mechanism

International Nuclear Information System (INIS)

Liu, Xianbin; Shan, Dayong; Song, Yingwei; Han, En-hou

2015-01-01

The influence of assembled time on the corrosion behaviors of SAMs film on the AM60B alloy and its assembled mechanism have been investigated by electrochemical measurements, scanning electron microscopy (SEM) observation and X-ray photoelectron spectroscopy (XPS) analysis. The self-assembled experiment on the AM60B magnesium alloy indicates that the corrosion susceptibility decreases with increasing assembled time until 24 h on cast AM60B alloy and then increases with increase of the assembled time proved by EIS measurement and potentiodynamic curves. The self-assembled experiments on pure magnesium and various heat treated cast AM60B magnesium alloy illuminate that the dissolved aluminum in magnesium solid solution is the key factor for assembled efficiency and is hard to self-assemble on the pure magnesium without aluminum. The corrosion resistance of self-assembled film on AM60B magnesium alloy is monotonically increasing with the dissolved aluminum. The results of XPS analysis reveal the assembled mechanism on AM60B and corroborate the function of Al element. - Highlights: • It is hard to self-assemble on the pure magnesium. • 24 h assembled film has the low corrosion susceptibility by EIS and polarization. • The corrosion susceptibility of SAMs film lie on the Al atom state in AM60B. • The corrosion susceptibility of SAMs film is decreasing with the dissolved Al

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

Novel transparent and flexible nanocomposite film prepared from chrysotile nanofibres

International Nuclear Information System (INIS)

Liu, Kun; Zhu, Binnan; Feng, Qiming; Duan, Tao

2013-01-01

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

Laser-induced diffusion decomposition in Fe–V thin-film alloys

Energy Technology Data Exchange (ETDEWEB)

Polushkin, N.I., E-mail: nipolushkin@fc.ul.pt [Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa (Portugal); Instituto de Ciência e Engenharia de Materiais e Superfícies, 1049-001 Lisboa (Portugal); Duarte, A.C.; Conde, O. [Departamento de Física, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa (Portugal); Instituto de Ciência e Engenharia de Materiais e Superfícies, 1049-001 Lisboa (Portugal); Alves, E. [Associação Euratom/IST e Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa (Portugal); Barradas, N.P. [Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, 2695-066 Bobadela LRS (Portugal); García-García, A.; Kakazei, G.N.; Ventura, J.O.; Araujo, J.P. [Departamento de Física, Universidade do Porto e IFIMUP, 4169-007 Porto (Portugal); Oliveira, V. [Instituto de Ciência e Engenharia de Materiais e Superfícies, 1049-001 Lisboa (Portugal); Instituto Superior de Engenharia de Lisboa, 1959-007 Lisboa (Portugal); Vilar, R. [Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa (Portugal); Instituto de Ciência e Engenharia de Materiais e Superfícies, 1049-001 Lisboa (Portugal)

2015-05-01

Highlights: • Irradiation of an Fe–V alloy by femtosecond laser triggers diffusion decomposition. • The decomposition occurs with strongly enhanced (∼4 orders) atomic diffusivity. • This anomaly is associated with the metallic glassy state achievable under laser quenching. • The ultrafast diffusion decomposition is responsible for laser-induced ferromagnetism. - Abstract: We investigate the origin of ferromagnetism induced in thin-film (∼20 nm) Fe–V alloys by their irradiation with subpicosecond laser pulses. We find with Rutherford backscattering that the magnetic modifications follow a thermally stimulated process of diffusion decomposition, with formation of a-few-nm-thick Fe enriched layer inside the film. Surprisingly, similar transformations in the samples were also found after their long-time (∼10{sup 3} s) thermal annealing. However, the laser action provides much higher diffusion coefficients (∼4 orders of magnitude) than those obtained under standard heat treatments. We get a hint that this ultrafast diffusion decomposition occurs in the metallic glassy state achievable in laser-quenched samples. This vitrification is thought to be a prerequisite for the laser-induced onset of ferromagnetism that we observe.

Double switching hysteresis loop in a single layer Fe3Pt alloy thin films

International Nuclear Information System (INIS)

Nahid, M.A.I.; Suzuki, Takao

2008-01-01

The Fe 3 Pt alloy thin films were epitaxially grown on MgO(100) substrate by e-beam evaporation. The films were partially ordered at the substrate deposition temperature above 350 deg. C. These partially ordered films exhibit very large biaxial magnetic anisotropy constant in the order of 10 5 J/m 3 and produce double switching in the hysteresis loops. The difference of the switching field of these films can be up to about 3 x 10 5 A/m by tuning the angle of the applied field with respect to the easy axes. This double switching behavior stems from the large biaxial magnetic anisotropy of the films

Studying the initial stages of film electrodeposition of magnetic cobalt-tungsten alloys

International Nuclear Information System (INIS)

Rachinskas, V.S.; Orlovskaya, L.V.; Parfenov, V.A.; Yasulajtene, V.V.

1996-01-01

Initial stages of magnetic film electrodeposition by recording potentiodynamic polarization and j c ,t-curves, determination of surface structure of electrolytically deposited films by the method of XPS and study of thin coating properties have been considered. It is shown that at initial stage of electrodeposition of magnetic Co-W-films a sharp decrease in cathode process rate and formation of Co(OH) 2 , WO 3 and/or WO 4 2- occur on Cu-cathode surface. Electrodeposition of metallic magnetic Co-W-alloy, consisting of Co, W and containing basic compounds of co-deposited metals, takes place after a certain time period depending on deposition E c . 6 refs.; 3 figs

Study on the early surface films formed on Mg-Y molten alloy in different atmospheres

Directory of Open Access Journals (Sweden)

A.R. Mirak

2015-09-01

Full Text Available In the present study, the non-isothermal early stages of surface oxidation of liquid Mg-1%Y alloy during casting were studied under UPH argon, dry air, and air mixed with protective fluorine-bearing gases. The chemistry and morphology of the surface films were characterized by SEM and EDX analyses. The results indicate a layer of smooth and tightly coherent oxidation film composed of MgO and Y2O3 formed on the molten Mg-Y alloy surface with 40–60 nm thickness under dry air. A dendritic/cellular microstructure is clearly visible with Y-rich second phases gathered in surface of the melt and precipitated along the grain/cell boundaries under all gas conditions. Under fluorine-bearing gas mixtures, the surface film was a mixed oxide and fluoride and more even; a flat and folded morphology can be seen under SF6 with oxide as dominated phase and under 1, 1, 1, 2-tetra-fluoroethane, a smooth and compact surface film uniformly covering the inner surface of the bubble with equal oxide and fluoride thickness, which results in a film without any major defects. MgF2 phase appears to be the key characteristic of a good protective film.

Microstructure evolution and coercivity enhancement in Nd-Fe-B thin films diffusion-processed by R-Al alloys (R=Nd, Pr)

Science.gov (United States)

Xie, Yigao; Yang, Yang; Zhang, Tongbo; Fu, Yanqing; Jiang, Qingzheng; Ma, Shengcan; Zhong, Zhenchen; Cui, Weibin; Wang, Qiang

2018-05-01

Diffusion process by Nd-Al and Pr-Al alloys was compared and investigated in Nd-Fe-B thin films. Enhanced coercivity 2.06T and good squareness was obtained by using Pr85Al15 and Nd85Al15 alloys as diffusion sources. But the coercivity of diffusion-processed thin films by Pr70Al30 and Pr55Al45 alloys decreased to 2.04T and 1.82T. High ambient coercivity of 2.26T was achieved in diffusion-processed thin film by Nd70Al30 leading to an improved coercivity thermal stability because Nd2Fe14B grains were enveloped by Nd-rich phase as seen by transmission electron microscopy Nd-loss image. Meanwhile, microstructure-dependent parameters α and Neff were improved. However, high content of Al in diffusion-processed thin film by Nd55Al45 lead to degraded texture and coercivity.

Magnetic and thermal properties of amorphous TbFeCo alloy films

Science.gov (United States)

Wang, Ke; Dong, Shuo; Huang, Ya; Qiu, Yuzhen

2017-07-01

Amorphous TbFeCo material with perpendicular magnetic anisotropy is currently attracting more attention for potential applications in spintronic devices and logic memories. We systematically investigate magnetic, structural, thermal, optical and electrical properties of TbFeCo alloy films. It shows out-of-plane easy axis of the films turns into in-plane orientation after annealing. Significant increase in saturation magnetization in the temperature range between 400 and 450 °C is revealed by thermomagnetic measurements. The occurrence of crystallization and oxidation at high temperatures is confirmed by X-ray diffraction measurements. Pronounced changes in optical reflectance and sheet resistance are observed with temperature, in line with structural relaxation and change. The activation barriers for crystallization and oxidation are determined to be 1.01 eV and 0.83 eV, respectively, for FeCo-rich and Tb-rich samples. Better thermal stability against crystallization and oxidation is demonstrated in the FeCo-rich sample than the Tb-rich type. Our results provide some useful information for the alloy used in device fabrication.

A comparative chemical network study of HWCVD deposited amorphous silicon and carbon based alloys thin films

Energy Technology Data Exchange (ETDEWEB)

Swain, Bibhu P., E-mail: bibhuprasad.swain@gmail.com [Centre for Materials Science and Nanotechnology, Sikkim Manipal Institute of Technology, Majitar, Rangpo Sikkim (India); Swain, Bhabani S.; Hwang, Nong M. [Thin Films and Microstructure Laboratory, Department of Materials Science and Engineering, Seoul National University, Seoul (Korea, Republic of)

2014-03-05

Highlights: • a-SiC:H, a-SiN:H, a-C:H and a-SiCN:H films were deposited by hot wire chemical vapor deposition. • Evolution of microstructure of a-SiCN:H films deposited at different NH{sub 3} flow rate were analyzed. • The chemical network of Si and C based alloys were studied by FTIR and Raman spectroscopy. -- Abstract: Silicon and carbon based alloys were deposited by hot wire chemical vapor deposition (HWCVD). The microstructure and chemical bonding of these films were characterized by field emission scanning electron microscopy, Fourier transform infrared spectroscopy and Raman spectroscopy. The electron microscopy revealed various microstructures were observed for a-C:H, a-SiC:H, a-SiN:H, a-CN:H and a-SiCN:H films. The microstructure of SiN:H films showed agglomerate spherical grains while a-C:H films showed more fractal surface with branched microstructure. However, a-SiC:H, a-CN:H and a-SiCN:H indicated uniform but intermediate surface fractal microstructure. A series of a-SiCN:H films were deposited with variation of NH{sub 3} flow rate. The nitrogen incorporation in a-SiCN:H films alter the carbon network from sp{sup 2} to sp{sup 3} bonding The detail chemical bonding of amorphous films was analyzed by curve fitting method.

Single-phase {beta}-FeSi{sub 2} thin films prepared on Si wafer by femtosecond laser ablation and its photoluminescence at room temperature

Energy Technology Data Exchange (ETDEWEB)

Lu Peixiang [State Key Laboratory of Laser Technology and Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074 (China)]. E-mail: lupeixiang@mail.hust.edu.cn; Zhou Youhua [State Key Laboratory of Laser Technology and Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074 (China) and Physics and Information School, Jianghan University, Wuhan 430056 (China)]. E-mail: yhzhou@jhun.edu.cn; Zheng Qiguang [State Key Laboratory of Laser Technology and Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074 (China); Yang Guang [State Key Laboratory of Laser Technology and Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074 (China)

2006-02-06

Single-phase {beta}-FeSi{sub 2} thin films were prepared on Si(100) and Si(111) wafers by using femtosecond laser deposition with a FeSi{sub 2} alloy target for the first time. X-ray diffraction (XRD), field scanning electron microscopy (FSEM), scanning probe microscopy (SPM), electron backscattered diffraction pattern (EBSD), and Fourier-transform Raman infrared spectroscopy (FTRIS) were used to characterize the structure, composition, and properties of the {beta}-FeSi{sub 2}/Si films. The orientation of {beta}-FeSi{sub 2} grains was found to depend on the orientation of the Si substrates, and photoluminescence at wavelength of 1.53 {mu}m was observed from the single-phase {beta}-FeSi{sub 2}/Si thin film at room temperature (20 {sup o}C)

Multifold Seebeck increase in RuO{sub 2} films by quantum-guided lanthanide dilute alloying

Energy Technology Data Exchange (ETDEWEB)

Music, Denis, E-mail: music@mch.rwth-aachen.de; Basse, Felix H.-U.; Schneider, Jochen M. [Materials Chemistry, RWTH Aachen University, Kopernikusstr. 10, D-52074 Aachen (Germany); Han, Liang; Borca-Tasciuc, Theo [Department of Mechanical, Aerospace and Nuclear Engineering, Rensselaer Polytechnic Institute, 110 8th St., Troy, New York 12180 (United States); Devender [Materials Science and Engineering Department, Rensselaer Polytechnic Institute, 110 8th St., Troy, New York 12180 (United States); Gengler, Jamie J. [Air Force Research Laboratory, Materials and Manufacturing Directorate, WPAFB, Ohio 45433 (United States); Spectral Energies, LLC, Dayton, Ohio 45431 (United States); Voevodin, Andrey A. [Air Force Research Laboratory, Materials and Manufacturing Directorate, WPAFB, Ohio 45433 (United States); Ramanath, Ganpati [Materials Chemistry, RWTH Aachen University, Kopernikusstr. 10, D-52074 Aachen (Germany); Materials Science and Engineering Department, Rensselaer Polytechnic Institute, 110 8th St., Troy, New York 12180 (United States)

2014-02-03

Ab initio predictions indicating that alloying RuO{sub 2} with La, Eu, or Lu can increase the Seebeck coefficient α manifold due to quantum confinement effects are validated in sputter-deposited La-alloyed RuO{sub 2} films showing fourfold α increase. Combinatorial screening reveals that α enhancement correlates with La-induced lattice distortion, which also decreases the thermal conductivity twentyfold, conducive for high thermoelectric figures of merit. These insights should facilitate the rational design of high efficiency oxide-based thermoelectrics through quantum-guided alloying.

Quantitative analysis of reflection electron energy loss spectra to determine electronic and optical properties of Fe–Ni alloy thin films

International Nuclear Information System (INIS)

Tahir, Dahlang; Oh, Sukh Kun; Kang, Hee Jae; Tougaard, Sven

2016-01-01

Highlights: • Electronic and optical properties of Fe-Ni alloy thin films grown on Si (1 0 0) were studied via quantitative analyses of reflection electron energy loss spectra (REELS). • The energy loss functions (ELF) are dominated by a plasmon peak at 23.6 eV for Fe and moves gradually to lower energies in Fe-Ni alloys towards the bulk plasmon energy of Ni at 20.5 eV. • Fe has a strong effect on the dielectric and optical properties of Fe-Ni alloy thin films even for an alloy with 72% Ni. Electronic and optical properties of Fe-Ni alloy thin films grown on Si (1 0 0) were studied via quantitative analyses of reflection electron energy loss spectra (REELS). - Abstract: Electronic and optical properties of Fe–Ni alloy thin films grown on Si (1 0 0) by ion beam sputter deposition were studied via quantitative analyses of reflection electron energy loss spectra (REELS). The analysis was carried out by using the QUASES-XS-REELS and QUEELS-ε(k,ω)-REELS softwares to determine the energy loss function (ELF) and the dielectric functions and optical properties by analyzing the experimental spectra. For Ni, the ELF shows peaks around 3.6, 7.5, 11.7, 20.5, 27.5, 67 and 78 eV. The peak positions of the ELF for Fe_2_8Ni_7_2 are similar to those of Fe_5_1Ni_4_9, even though there is a small peak shift from 18.5 eV for Fe_5_1Ni_4_9 to 18.7 eV for Fe_2_8Ni_7_2. A plot of n, k, ε_1, and ε_2 shows that the QUEELS-ε(k,ω)-REELS software for analysis of REELS spectra is useful for the study of optical properties of transition metal alloys. For Fe–Ni alloy with high Ni concentration (Fe_2_8Ni_7_2), ε_1, and ε_2 have strong similarities with those of Fe. This indicates that the presence of Fe in the Fe–Ni alloy thin films has a strong effect.

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...

Manipulating magnetic anisotropy of the ultrathin Co{sub 2}FeAl full-Heusler alloy film via growth orientation of the Pt buffer layer

Energy Technology Data Exchange (ETDEWEB)

Wen, F.S., E-mail: wenfsh03@126.com [State Key Lab of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Xiang, J.Y.; Hao, C.X.; Zhang, F.; Lv, Y.F. [State Key Lab of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Wang, W.H. [Institute of Physics, Chinese Academy of Science, Beijing 100080 (China); Hu, W.T.; Liu, Z.Y. [State Key Lab of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China)

2013-12-15

The ultrathin films of Co{sub 2}FeAl (CFA) full-Heusler alloy were prepared between two Pt layers on MgO single crystals by magnetron sputtering. By controlling the substrate temperature, different growth orientations of the Pt underlayers were realized, and their effects were investigated on the magnetic anisotropy of the ultrathin CFA film. It was revealed that different Pt orientations lead to distinctly different magnetic anisotropy for the sandwiched ultrathin CFA films. The Pt (111) orientation favors the perpendicular anisotropy, while the appearance of partial Pt (001) orientation leads to the quick decrease of perpendicular anisotropy and the complete Pt (001) orientation gives rise to the in-plane anisotropy. With the Pt (111) orientation, the temperature and thickness-induced spin reorientation transitions were investigated in the sandwiched ultrathin CFA films. - Highlights: • Different Pt orientations lead to different magnetic anisotropy for sandwiched ultrathin CFA films. • The Pt (111) orientation favors the perpendicular anisotropy for CFA layer. • Temperature and thickness-induced spin reorientation transitions were investigated in sandwiched ultrathin CFA films. • 0.8 nm CFA film is good candidate as electrode in magnetic tunnel junctions.

Rapid Obtaining of Nano-Hydroxyapatite Bioactive Films on NiTi Shape Memory Alloy by Electrodeposition Process

Science.gov (United States)

Lobo, A. O.; Otubo, J.; Matsushima, J. T.; Corat, E. J.

2011-07-01

Nano-hydroxyapatite (n-HA) crystalline films have been developed in this study by electrodeposition method on NiTi shape memory alloy (SMA). The electrodeposition of the n-HA films was carried out using 0.042 mol/L Ca(NO3)2 · 4H2O + 0.025 mol/L (NH4) · 2HPO4 electrolytes by applying a constant potential of -2.0 V for 120 min and keeping the solution temperature at 70 °C. The characterization of n-HA films is of special importance since bioactive properties related to n-HA have been directly identified with its specific composition and crystalline structure. AFM, XRD, EDX, FEG-SEM and Raman spectroscopy shows a homogeneous film, with high crystallinity, special composition, and bioactivity properties (Ca/P = 1.93) of n-HA on NiTi SMA surfaces. The n-HA coating with special structure would benefit the use of NiTi alloy in orthopedic applications.

Design and fabrication of enhanced corrosion resistance Zn-Al layered double hydroxides films based anion-exchange mechanism on magnesium alloys

International Nuclear Information System (INIS)

Zhou, Meng; Yan, Luchun; Ling, Hao; Diao, Yupeng; Pang, Xiaolu; Wang, Yanlin; Gao, Kewei

2017-01-01

Highlights: • Zn-Al LDHs film loaded nitrate anions has been fabricated on a magnesium alloy substrate via a facile hydrothermal crystallization method. • The Zn-Al-Cl LDHs and Zn-Al-VO_x LDHs film were obtained based on anion-exchange mechanism. • The Zn-Al-Cl LDHs and Zn-Al-VO_x LDHs film could effectively protect magnesium alloy. - Abstract: Layered double hydroxides (LDHs) with brucite-like layer structure and the facile exchangeability of intercalated anions had attracted tremendous interest in many fields because of their great importance for both fundamental studies and practical applications. Herein zinc-aluminum layered double hydroxides (Zn-Al LDHs) films intercalated with nitrate anions on the magnesium alloy substrate were designed and fabricated via a facile hydrothermal crystallization method. In order to obtain better corrosion resistance, chloride and vanadate anions were intercalated into the LDHs interlayers via the anion-exchange reaction. X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and scanning electronic microscopy (SEM) were used to examine structure, composition and morphology of the Zn-Al-NO_3 LDHs, Zn-Al-Cl LDHs and Zn-Al-VO_x LDHs films. The corrosion resistance of the Zn-Al LDHs with different anion films was estimated by the electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization measurement. EIS and polarization curves measurements revealed that the magnesium alloy could be effectively protected by the Zn-Al-Cl LDHs and Zn-Al-VO_x LDHs films due to the blocking effect of chloride anions and the control-release ability of vanadate anions.

Design and fabrication of enhanced corrosion resistance Zn-Al layered double hydroxides films based anion-exchange mechanism on magnesium alloys

Energy Technology Data Exchange (ETDEWEB)

Zhou, Meng; Yan, Luchun; Ling, Hao; Diao, Yupeng; Pang, Xiaolu; Wang, Yanlin; Gao, Kewei, E-mail: kwgao@yahoo.com

2017-05-15

Highlights: • Zn-Al LDHs film loaded nitrate anions has been fabricated on a magnesium alloy substrate via a facile hydrothermal crystallization method. • The Zn-Al-Cl LDHs and Zn-Al-VO{sub x} LDHs film were obtained based on anion-exchange mechanism. • The Zn-Al-Cl LDHs and Zn-Al-VO{sub x} LDHs film could effectively protect magnesium alloy. - Abstract: Layered double hydroxides (LDHs) with brucite-like layer structure and the facile exchangeability of intercalated anions had attracted tremendous interest in many fields because of their great importance for both fundamental studies and practical applications. Herein zinc-aluminum layered double hydroxides (Zn-Al LDHs) films intercalated with nitrate anions on the magnesium alloy substrate were designed and fabricated via a facile hydrothermal crystallization method. In order to obtain better corrosion resistance, chloride and vanadate anions were intercalated into the LDHs interlayers via the anion-exchange reaction. X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and scanning electronic microscopy (SEM) were used to examine structure, composition and morphology of the Zn-Al-NO{sub 3} LDHs, Zn-Al-Cl LDHs and Zn-Al-VO{sub x} LDHs films. The corrosion resistance of the Zn-Al LDHs with different anion films was estimated by the electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization measurement. EIS and polarization curves measurements revealed that the magnesium alloy could be effectively protected by the Zn-Al-Cl LDHs and Zn-Al-VO{sub x} LDHs films due to the blocking effect of chloride anions and the control-release ability of vanadate anions.

Al-Co Alloys Prepared by Vacuum Arc Melting: Correlating Microstructure Evolution and Aqueous Corrosion Behavior with Co Content

Directory of Open Access Journals (Sweden)

Angeliki Lekatou

2016-02-01

Full Text Available Hypereutectic Al-Co alloys of various Co contents (7–20 weight % (wt.% Co were prepared by vacuum arc melting, aiming at investigating the influence of the cobalt content on the microstructure and corrosion behavior. Quite uniform and directional microstructures were attained. The obtained microstructures depended on the Co content, ranging from fully eutectic growth (7 wt.% and 10 wt.% Co to coarse primary Al9Co2 predominance (20 wt.% Co. Co dissolution in Al far exceeded the negligible equilibrium solubility of Co in Al; however, it was hardly uniform. By increasing the cobalt content, the fraction and coarseness of Al9Co2, the content of Co dissolved in the Al matrix, and the hardness and porosity of the alloy increased. All alloys exhibited similar corrosion behavior in 3.5 wt.% NaCl with high resistance to localized corrosion. Al-7 wt.% Co showed slightly superior corrosion resistance than the other compositions in terms of relatively low corrosion rate, relatively low passivation current density and scarcity of stress corrosion cracking indications. All Al-Co compositions demonstrated substantially higher resistance to localized corrosion than commercially pure Al produced by casting, cold rolling and arc melting. A corrosion mechanism was formulated. Surface films were identified.

Process of film formation by anodizing AZ91D magnesium alloy

Energy Technology Data Exchange (ETDEWEB)

Qian Jiangang; Li Di; Zhang Feng [School of Materials Science and Engineering, Beijing Univ. of Aeronautics and Astronautics (China)

2005-07-01

The kinetics of film-forming process by anodizing AZ91D Mg alloy has been studied by ways of voltage-time and thickness-time curve, and the surface morphology, structure, composition and valence of element, phase constituent of anodic films have been analyzed by SEM, EDS, XPS and XRD respectively. The results show that the film-forming course can be divided into four stages. Formation of dense layer before sparking is the first stage. Formation of porous layer accompanied with a bit of small sparking is the second stage. Porous layer fast growth along with middle sparking is the third stage. Porous layer slowly-growth along with bigger sparking is the fourth stage. The anodic films contains approximately Mg,O,Si and B, which is composed mainly of MgO, MgSiO{sub 3} and Mg{sub 3}B{sub 2}O{sub 6}. (orig.)

Electrical and structural characterization of Nb-Si thin alloy film

International Nuclear Information System (INIS)

Nava, F.; Psaras, P.A.; Takai, H.; Tu, K.N.; Valeri, S.; Bisi, O.

1986-01-01

The structural and electrical properties of a Nb-Si thin alloy film as a function of temperature have been studied by Auger electron spectrometry, Rutherford backscattering spectroscopy, transmission electron microscopies, and in situ electrical resistivity and Hall coefficient measurements. The NbSi/sub 2.8/ films were deposited by double electron-gun coevaporation onto oxidized silicon. For electrical measurements samples of a van der Pauw pattern were made through metallic masks. In the as-deposited state the coevaporated alloy film was amorphous. Upon annealing a precipitous drop in resistivity near 270 0 C has been determined to be the amorphous to crystalline phase transformation. The kinetics of the transformation has been determined by isothermal heat treatment over the temperature range of 224 0 to 252 0 C. An apparent activation energy of 1.90 eV has been measured. The nucleation and growth kinetics in the crystallization process show a change in the power of time dependence from 5.5 to 2.4. The microstructures of films at various states of annealing have been correlated to the resistivity change. The crystalline NbSi 2 shows an anomalous metallic behavior. The resistivity (rho) versus temperature curve has a large negative deviation from linearity (dfl) and it approaches a saturation value (rho/sub sat/) as temperature increases. The resistivity data are fitted by two empirical expressions put forth to explain the resistivity behavior in A15 superconductors at low and high temperatures. One is based on the idea that ideal resistivity must approach some limiting value in the regime where the mean free path becomes comparable to the interatomic spacing and the other is based on a selective electron--phonon assisted scattering

Preparation of Pt Ag alloy nanoisland/graphene hybrid composites and its high stability and catalytic activity in methanol electro-oxidation

Directory of Open Access Journals (Sweden)

Feng Lili

2011-01-01

Full Text Available Abstract In this article, PtAg alloy nanoislands/graphene hybrid composites were prepared based on the self-organization of Au@PtAg nanorods on graphene sheets. Graphite oxides (GO were prepared and separated to individual sheets using Hummer's method. Graphene nano-sheets were prepared by chemical reduction with hydrazine. The prepared PtAg alloy nanomaterial and the hybrid composites with graphene were characterized by SEM, TEM, and zeta potential measurements. It is confirmed that the prepared Au@PtAg alloy nanorods/graphene hybrid composites own good catalytic function for methanol electro-oxidation by cyclic voltammograms measurements, and exhibited higher catalytic activity and more stability than pure Au@Pt nanorods and Au@AgPt alloy nanorods. In conclusion, the prepared PtAg alloy nanoislands/graphene hybrid composites own high stability and catalytic activity in methanol electro-oxidation, so that it is one kind of high-performance catalyst, and has great potential in applications such as methanol fuel cells in near future.

Structure and hardness of a hard metal alloy prepared with a WC powder synthesized at low temperature

Energy Technology Data Exchange (ETDEWEB)

Costa, F.A. da [Programa de Pos-Graduacao em Ciencia e Engenharia de Materiais, UFRN, Campus Universitario, 59072-970 Natal, RN (Brazil)], E-mail: francineac@yahoo.com; Medeiros, F.F.P. de [Programa de Pos-Graduacao em Ciencia e Engenharia de Materiais, UFRN, Campus Universitario, 59072-970 Natal, RN (Brazil); Silva, A.G.P. da [Laboratorio de Materiais Avancados, UENF, 28015-620 Campos de Goytacazes, RJ (Brazil); Gomes, U.U. [Departamento de Fisica Teorica e Experimental, UFRN, Campus Universitario, 59072-970 Natal, RN (Brazil); Filgueira, M. [Laboratorio de Materiais Avancados, UENF, 28015-620 Campos de Goytacazes, RJ (Brazil); Souza, C.P. de [Laboratorio de Termodinamica e Reatores, UFRN, Campus Universitario, 59072-970 Natal, RN (Brazil)

2008-06-25

The structure and hardness of a WC-10 wt% Co alloy prepared with an experimental WC powder are compared with those of another alloy of the same composition produced under the same conditions and prepared with a commercial WC powder. The experimental WC powder was synthesized by a gas-solid reaction between APT and methane at low temperature and the commercial WC powder was conventionally produced by a solid-solid reaction between tungsten and carbon black. WC-10 wt% Co alloys with the two powders were prepared under the same conditions of milling and sintering. The structure of the sample prepared with the experimental WC powder is homogeneous and coarse grained. The structure of the sample prepared with the commercial powder is heterogeneous. Furthermore the size and shape of the WC grains are significantly different.

Semiconducting behavior of the anodically passive films formed on AZ31B alloy

Directory of Open Access Journals (Sweden)

A. Fattah-alhosseini

2014-12-01

Full Text Available This work includes determination of the semiconductor character and estimation of the dopant levels in the passive film formed on AZ31B alloy in 0.01 M NaOH, as well as the estimation of the passive film thickness as a function of the film formation potential. Mott–Schottky analysis revealed that the passive films displayed n-type semiconductive characteristics, where the oxygen vacancies and interstitials preponderated. Based on the Mott–Schottky analysis, it was shown that the calculated donor density increases linearly with increasing the formation potential. Also, the electrochemical impedance spectroscopy (EIS results indicated that the thickness of the passive film was decreased linearly with increasing the formation potential. The results showed that decreasing the formation potential offer better conditions for forming the passive films with higher protection behavior, due to the growth of a much thicker and less defective films.

Preparation of transparent conducting zinc oxide films by rf reactive sputtering

International Nuclear Information System (INIS)

Vasanelli, L.; Valentini, A.; Losacco, A.

1986-01-01

Transparent conducting zinc oxide films have been prepared by reactive sputtering in a Ar/H/sub 2/ mixture. The optical and electrical properties of the films are presented and discussed. The effects of some post-deposition thermal treatment have been also investigated. ZnO/CdTe heterojunctions have been prepared by sputtering ZnO films on CdTe single crystals. The photovoltaic conversion efficiencies of the obtained solar cells was 6.8%

Characterization of AZO and Ag based films prepared by RF magnetron sputtering

International Nuclear Information System (INIS)

Miao, Dagang; Jiang, Shouxiang; Zhao, Hongmei; Shang, Songmin; Chen, Zhuoming

2014-01-01

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

Electrochemical synthesis of mesoporous Pt-Au binary alloys with tunable compositions for enhancement of electrochemical performance.

Science.gov (United States)

Yamauchi, Yusuke; Tonegawa, Akihisa; Komatsu, Masaki; Wang, Hongjing; Wang, Liang; Nemoto, Yoshihiro; Suzuki, Norihiro; Kuroda, Kazuyuki

2012-03-21

Mesoporous Pt-Au binary alloys were electrochemically synthesized from lyotropic liquid crystals (LLCs) containing corresponding metal species. Two-dimensional exagonally ordered LLC templates were prepared on conductive substrates from diluted surfactant solutions including water, a nonionic surfactant, ethanol, and metal species by drop-coating. Electrochemical synthesis using such LLC templates enabled the preparation of ordered mesoporous Pt-Au binary alloys without phase segregation. The framework composition in the mesoporous Pt-Au alloy was controlled simply by changing the compositional ratios in the precursor solution. Mesoporous Pt-Au alloys with low Au content exhibited well-ordered 2D hexagonal mesostructures, reflecting those of the original templates. With increasing Au content, however, the mesostructural order gradually decreased, thereby reducing the electrochemically active surface area. Wide-angle X-ray diffraction profiles, X-ray photoelectron spectra, and elemental mapping showed that both Pt and Au were atomically distributed in the frameworks. The electrochemical stability of mesoporous Pt-Au alloys toward methanol oxidation was highly improved relative to that of nonporous Pt and mesoporous Pt films, suggesting that mesoporous Pt-Au alloy films are potentially applicable as electrocatalysts for direct methanol fuel cells. Also, mesoporous Pt-Au alloy electrodes showed a highly sensitive amperometric response for glucose molecules, which will be useful in next-generation enzyme-free glucose sensors.

Effect of Substrate Roughness on Adhesion and Structural Properties of Ti-Ni Shape Memory Alloy Thin Film.

Science.gov (United States)

Kim, Donghwan; Lee, Hyunsuk; Bae, Joohyeon; Jeong, Hyomin; Choi, Byeongkeun; Nam, Taehyun; Noh, Jungpil

2018-09-01

Ti-Ni shape memory alloy (SMA) thin films are very attractive material for industrial and medical applications such as micro-actuator, micro-sensors, and stents for blood vessels. An important property besides shape memory effect in the application of SMA thin films is the adhesion between the film and the substrate. When using thin films as micro-actuators or micro-sensors in MEMS, the film must be strongly adhered to the substrate. On the other hand, when using SMA thin films in medical devices such as stents, the deposited alloy thin film must be easily separable from the substrate for efficient processing. In this study, we investigated the effect of substrate roughness on the adhesion of Ti-Ni SMA thin films, as well as the structural properties and phase-transformation behavior of the fabricated films. Ti-Ni SMA thin films were deposited onto etched glass substrates with magnetron sputtering. Radio frequency plasma was used for etching the substrate. The adhesion properties were investigated through progressive scratch test. Structural properties of the films were determined via Feld emission scanning electron microscopy, X-ray diffraction measurements (XRD) and Energy-dispersive X-ray spectroscopy analysis. Phase transformation behaviors were observed with differential scanning calorimetry and low temperature-XRD. Ti-Ni SMA thin film deposited onto rough substrate provides higher adhesive strength than smooth substrate. However the roughness of the substrate has no influence on the growth and crystallization of the Ti-Ni SMA thin films.

Thin films prepared from tungstate glass matrix

Energy Technology Data Exchange (ETDEWEB)

Montanari, B.; Ribeiro, S.J.L.; Messaddeq, Y. [Departamento de Quimica Geral e Inorganica, Instituto de Quimica, Sao Paulo State University-UNESP, CP 355, CEP 14800-900, Araraquara, SP (Brazil); Li, M.S. [Instituto de Fisica, USP, CP 369, CEP 13560-970, Sao Carlos, SP (Brazil); Poirier, G. [Departamento de Ciencias Exatas, UNIFAL-MG, CEP 37130-000, Alfenas-MG (Brazil)], E-mail: gael@unifal-mg.edu.br

2008-01-30

Vitreous samples containing high concentrations of WO{sub 3} (above 40% M) have been used as a target to prepare thin films. Such films were deposited using the electron beam evaporation method onto soda-lime glass substrates. These films were characterized by X-ray diffraction (XRD), perfilometry, X-ray energy dispersion spectroscopy (EDS), M-Lines and UV-vis absorption spectroscopy. In this work, experimental parameters were established to obtain stable thin films showing a chemical composition close to the glass precursor composition and with a high concentration of WO{sub 3}. These amorphous thin films of about 4 {mu}m in thickness exhibit a deep blue coloration but they can be bleached by thermal treatment near the glass transition temperature. Such bleached films show several guided modes in the visible region and have a high refractive index. Controlled crystallization was realized and thus it was possible to obtain WO{sub 3} microcrystals in the amorphous phase.

Mining, ore preparation and niobium alloys production at Araxa, Brazil

International Nuclear Information System (INIS)

Paraiso, O.S.; Fuccio Junior, R. de; Betz, E.W.

1984-01-01

A detailed description of the worlds major niobium producer is presented covering mining, concentration by froth flotation, leaching, and production of ferro-alloys. The present exploration of the Araxa deposit, its ore preparation and production of ferro-niobium is described. (E.G.) [pt

An optimized In–CuGa metallic precursors for chalcopyrite thin films

Energy Technology Data Exchange (ETDEWEB)

Han, Jun-feng, E-mail: junfeng.han@cnrs-imn.fr [Institut des Matériaux Jean Rouxel (IMN), Université de Nantes, UMR CNRS 6502, 2 rue de la Houssinière, BP 32229, 44322 Nantes Cedex 3 (France); Department of Physics, Peking University, Beijing 100871 (China); Liao, Cheng [Department of Physics, Peking University, Beijing 100871 (China); Chengdu Green Energy and Green Manufacturing Technology R and D Center, Chengdu, Sichuan Province 601207 (China); Jiang, Tao; Xie, Hua-mu; Zhao, Kui [Department of Physics, Peking University, Beijing 100871 (China); Besland, M.-P. [Institut des Matériaux Jean Rouxel (IMN), Université de Nantes, UMR CNRS 6502, 2 rue de la Houssinière, BP 32229, 44322 Nantes Cedex 3 (France)

2013-10-31

We report a study of CuGa–In metallic precursors for chalcopyrite thin film. CuGa and In thin films were prepared by DC sputtering at room temperature. Due to low melting point of indium, the sputtering power on indium target was optimized. Then, CuGa and In multilayers were annealed at low temperature. At 120 °C, the annealing treatment could enhance diffusion and alloying of CuGa and In layers; however, at 160 °C, it caused a cohesion and crystalline of indium from the alloy which consequently formed irregular nodules on the film surface. The precursors were selenized to form copper indium gallium selenide (CIGS) thin films. The morphological and structural properties were investigated by scanning electron microscopy, X-ray diffraction and Raman spectra. The relationships between metallic precursors and CIGS films were discussed in the paper. A smooth precursor layer was the key factor to obtain a homogeneous and compact CIGS film. - Highlights: • An optimized sputtered indium film • An optimized alloying process of metallic precursor • An observation of nodules forming on the indium film and precursor surface • An observation of cauliflower structure in copper indium gallium selenide film • The relationship between precursor and CIGS film surface morphology.

Dependence of the polar Kerr angle and coercivity on repeat distance in sequentially prepared Tb/FeCo films

International Nuclear Information System (INIS)

Shin, S.

1991-01-01

Multilayer thin films of Tb and FeCo were prepared by sequential thermal evaporation of Tb and Fe 90 Co 10 alloy on glass substrates at ambient temperature in a vacuum of about 1 x 10 -6 Torr. The repeat distance of the films was varied from 3.5 to 175 A while maintaining the composition constant for all samples. Low-angle x-ray diffraction and Auger electron spectroscopy showed that a multilayer structure was achieved for films fabricated with a repeat distance Λ≥31.5 A. The polar Kerr rotation angle and coercivity of the samples were obtained by measuring the polar Kerr hysteresis loop using a 632.8-nm HeNe laser. It was observed that for the samples having a multilayer structure, the remnant Kerr angle and coercivity monotonically decreased with increasing repeat distance, and eventually disappeared for Λ≥70 A. For the samples showing a nonmultilayer structure, the remnant Kerr angle was independent of repeat distance. However, the coercivity increased with repeat distance until a broad maximum was obtained around Λ congruent 14--21 A

The Effect of Cu:Ag Atomic Ratio on the Properties of Sputtered Cu–Ag Alloy Thin Films

Directory of Open Access Journals (Sweden)

Janghsing Hsieh

2016-11-01

Full Text Available Cu–Ag thin films with various atomic ratios were prepared using a co-sputtering technique, followed by rapid thermal annealing at various temperatures. The films’ structural, mechanical, and electrical properties were then characterized using X-ray diffractometry (XRD, atomic force microscopy (AFM, FESEM, nano-indentation, and TEM as functions of compositions and annealing conditions. In the as-deposited condition, the structure of these films transformed from a one-phase to a dual-phase state, and the resistivity shows a twin-peak pattern, which can be explained in part by Nordheim’s Rule and the miscibility gap of Cu–Ag alloy. After being annealed, the films’ resistivity followed the mixture rule in general, mainly due to the formation of a dual-phase structure containing Ag-rich and Cu-rich phases. The surface morphology and structure also varied as compositions and annealing conditions changed. The recrystallization of these films varied depending on Ag–Cu compositions. The annealed films composed of 40 at % to 60 at % Cu had higher hardness and lower roughness than those with other compositions. Particularly, the Cu50Ag50 film had the highest hardness after being annealed. From the dissolution testing, it was found that the Cu-ion concentration was about 40 times higher than that of Ag. The galvanic effect and over-saturated state could be the cause of the accelerated Cu dissolution and the reduced dissolution of the Ag.

Preparation and properties of a drug sustained-release hydrogel film

International Nuclear Information System (INIS)

Yue Ling; Yang Zhanshan; Yang Shuqin; Li Qinghua

2009-01-01

A hydrogel film of drug sustained-release was prepared to accelerate wound healing. The hydrogel films containing drug or not were prepared by the freezing and thawing process. Their properties such as the physicochemical property and the drug release behavior in vitro were studied. Effect of the freezing and thawing process on antimicrobial efficacy of the gentamicin was evaluated by diffusion method. The results indicate that swelling ratio of the hydrogel films freezed for 4h is 841.21% and their gel fraction, tensile strength and elongation at break is 96.10%, 0.222 MPa and 673.50% respectively. The antimicrobial efficacy of the gentamicin has no change. The hydrogel film contained gentamicin releases the antibiotic to peak during 6 h with the cumulative drug release rate of 59.57%. The drug releases continually up to the 5th day. The drug delivery conforms to Higuchi kinetic equation, and mechanism of the drug release is matrix diffusion. The results show that the hydrogel film prepared by the freezing and thawing process display satisfactory physicochemical properties and can be used as a drug delivery system. (authors)

Understanding the magnetic anisotropy in Fe-Si amorphous alloys

Energy Technology Data Exchange (ETDEWEB)

Diaz, J.; Hamdan, N.M.; Jalil, P.; Hussain, Z.; Valvidares, S.M.; Alameda, J.M.

2002-08-01

The origin of the magnetic anisotropy in a very disordered Fe-Si alloy has been investigated. The alloy containing 40 percent at. Si was prepared in the form of a thin film in a DC magnetron sputtering chamber. Structural disorder was obtained from Extended X-ray Absorption Fine Structure spectroscopy. The uniformity and lack of inhomogeneities at a microscopic level was checked by measuring their transverse magnetic susceptibility and hysteresis loops. The orbital component of the magnetic moment was measured by X-ray Magnetic Circular Dichroism spectroscopy. The orbital moment was extraordinary high, 0.4mB. Such a high value contrasted with the relatively small uniaxial anisotropy energy of the thin film (2kJ/m3). This suggests that the cause of the magnetic anisotropy in this alloy was a small degree of correlation in the orientation of the local orbital moments along a preferential direction.

Understanding the magnetic anisotropy in Fe-Si amorphous alloys

International Nuclear Information System (INIS)

Diaz, J.; Hamdan, N.M.; Jalil, P.; Hussain, Z.; Valvidares, S.M.; Alameda, J.M.

2002-01-01

The origin of the magnetic anisotropy in a very disordered Fe-Si alloy has been investigated. The alloy containing 40 percent at. Si was prepared in the form of a thin film in a DC magnetron sputtering chamber. Structural disorder was obtained from Extended X-ray Absorption Fine Structure spectroscopy. The uniformity and lack of inhomogeneities at a microscopic level was checked by measuring their transverse magnetic susceptibility and hysteresis loops. The orbital component of the magnetic moment was measured by X-ray Magnetic Circular Dichroism spectroscopy. The orbital moment was extraordinary high, 0.4mB. Such a high value contrasted with the relatively small uniaxial anisotropy energy of the thin film (2kJ/m3). This suggests that the cause of the magnetic anisotropy in this alloy was a small degree of correlation in the orientation of the local orbital moments along a preferential direction

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.

Effects of Preparation Conditions on the CuInS2 Films Prepared by One-Step Electrodeposition Method

Directory of Open Access Journals (Sweden)

Rongfeng Guan

2015-01-01

Full Text Available CuInS2 thin films were prepared onto indium tin oxide (ITO substrates by sulfurization of electrodeposited CuxInySz precursor films under S atmosphere. The influences of deposition potential, Cu2+/In3+ ratio, sulfurization temperature, and sulfur content on the CuInS2 thin films were investigated. Phases and structures were characterized by powder X-ray diffraction and Raman spectroscopy; surface morphology was characterized by Scanning Electron Microscopy; optical and electrical properties were characterized by UV-Vis absorption and Mott-Schottky curves, respectively. As a result, the optimal well-crystallized CuInS2 films preparation parameters were determined to be deposition potential of −0.8 V, Cu2+/In3+ ratio of 1.4, sulfur content of 1 g, and the sulfurization temperature of 550°C for 1 h; CuInS2 thin films prepared by one-step electrodeposition present the p-type semiconductor, with thickness about 4-5 μm and their optical band gaps in the range of 1.53~1.55 eV.

Hydrogen storage in thin film magnesium-scandium alloys

International Nuclear Information System (INIS)

Niessen, R.A. H.; Notten, P.H. L.

2005-01-01

Thorough electrochemical materials research has been performed on thin films of novel magnesium-scandium hydrogen storage alloys. It was found that palladium-capped thin films of Mg x Sc (1-x) with different compositions (ranging from x=0.50 -0.90) show an increase in hydrogen storage capacity of more than 5-20% as compared to their bulk equivalents using even higher discharge rates. The maximum reversible hydrogen storage capacity at the optimal composition (Mg 80 Sc 20 ) amounts to 1795-bar mAh/g corresponding to a hydrogen content of 2.05 H/M or 6.7-bar wt.%, which is close to five times that of the commonly used hydride-forming materials in commercial NiMH batteries. Galvanostatic intermittent titration technique (GITT) measurements show that the equilibrium pressure during discharge is lower than that of bulk powders by one order of magnitude (10 -7 -bar mbar versus 10 -6 -bar mbar, respectively)

Study of superficial films and of electrochemical behaviour of some nickel base alloys and titanium base alloys in solution representation of granitic, argillaceous and salted ground waters

International Nuclear Information System (INIS)

Quang, K.V.; Da Cunha Belo, M.; Benabed, M.S.; Bourelier, F.; Jallerat, N.; Pari, F.L.

1985-01-01

The corrosion behaviour of the stainless steels 304, 316 Ti, 25Cr-20Ni-Mo-Ti, nickel base alloys Hastelloy C4, Inconel 625, Incoloy 800, Ti and Ti-0.2% Pd alloy has been studied in the aerated or deaerated solutions at 20 0 C and 90 0 C whose compositions are representative of interstitial ground waters: granitic or clay waters or salt brine. The electrochemical techniques used are voltametry, polarization resistance and complexe impedance measurements. Electrochemical data show the respective influence of the parameters such as temperature, solution composition and dissolved oxygen, addition of soluble species chloride, fluoride, sulfide and carbonates, on which depend the corrosion current density, the passivation and the pitting potential. The inhibition efficiency of carbonate and bicarbonate activities against pitting corrosion is determined. In clay water at 90 0 C, Ti and Ti-Pd show very high passivation aptitude and a broad passive potential range. Alloying Pd increases cathodic overpotential and also transpassive potential. It makes the alloy less sensitive to the temperature effect. Optical Glow Discharge Spectra show three parts in the composition depth profiles of surface films on alloys. XPS and SIMS spectrometry analyses are also carried out. Electron microscopy observation shows that passive films formed on Ti and Ti-Pd alloy have amorphous structure. Analysis of the alloy constituents dissolved in solutions, by radioactivation in neutrons, gives the order of magnitude of the Ni base alloy corrosion rates in various media. It also points out the preferential dissolution of alloying iron and in certain cases of chromium

Preparation and corrosion resistance studies of nanometric sol-gel-based CeO2 film with a chromium-free pretreatment on AZ91D magnesium alloy

International Nuclear Information System (INIS)

Zhang Shiyan; Li Qing; Chen Bo; Yang Xiaokui

2010-01-01

Magnesium alloy, although valuable, is reactive and requires protection before it can be applied in many fields. In this study, a novel protective environmental-friendly gradient coating was performed on AZ91D magnesium alloy by non-chromate surface treatments, which consisted of phytic acid chemical conversion coating and the sol-gel-based CeO 2 thin film. The surface morphologies, microstructure and composition of the coatings were investigated by scanning electron microscopy (SEM), energy disperse spectroscopy (EDS) and X-ray diffraction (XRD), respectively. The corrosion resistance of the coatings was evaluated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) in 3.5 wt.% NaCl solution. The effects of the concentration, layers, temperature of heat treatment of CeO 2 sol on the anti-corrosion properties of the gradient coating for magnesium were also investigated. The results showed that the gradient coating was mainly composed of crystalline CeO 2 . According to the results of electrochemical tests, the corrosion resistance of AZ91D magnesium alloy was found to be greatly improved by means of this new environmental-friendly surface treatment.

Commissioning a hobby cutting device for radiochromic film preparation.

Science.gov (United States)

Zolfaghari, Somayeh; Francis, Kirby E; Kairn, Tanya; Crowe, Scott B

2017-06-01

In addition to a high spatial resolution and well characterised dose response, one of the major advantages of radiochromic film as a dosimeter is that sheets of film can be cut into pieces suitable for use as calibration films, and for in vivo and phantom measurements. The cutting of film is typically done using scissors or a guillotine, and this process can be time-consuming, limited in precision, requires extensive handling and does not allow holes to be cut from the film without cutting from an existing edge. This study investigated the use of a Brother ScanNCut hobby cutting system for EBT3 film preparation. The optimal operating parameters (blade size, pressure, speed) that resulted in precise cuts with minimal delamination at cut edges were identified using test cutting patterns. These parameters were then used to cut a large film insert for a stereotactic head phantom for comparison against an insert cut with scissors. While the hobby cutting system caused a wider region of delamination at the film edge (1.8 mm) compared to scissors (1 mm), the hobby cutting system was found to be able to produce reproducible cuts more efficiently and more accurately than scissors. The use of the hobby cutting system is recommended for complex phantom inserts (containing sharp corners or holes for alignment rods) or in situations where large numbers of film pieces need to be prepared.

A study on the electrodeposition of NiFe alloy thin films using chronocoulometry and electrochemical quartz crystal microgravimetry

CERN Document Server

Myung, N S

2001-01-01

Ni, Fe and NiFe alloy thin films were electrodeposited at a polycrystalline Au surface using a range of electrolytes and potentials. Coulometry and EQCM were used for real-time monitoring of electroplating efficiency of the Ni and Fe. The plating efficiency of NiFe alloy thin films was computed with the aid of ICP spectrometry. In general, plating efficiency increased to a steady value with deposition time. Plating efficiency of Fe was lower than that of Ni at -0.85 and -1.0 V but the efficiency approached to the similar plateau value to that of Ni at more negative potentials. The films with higher content of Fe showed different stripping behavior from the ones with higher content of Ni. Finally, compositional data and real-time plating efficiency are presented for films electrodeposited using a range of electrolytes and potentials.

Development of a flexible nanocomposite TiO{sub 2} film as a protective coating for bioapplications of superelastic NiTi alloys

Energy Technology Data Exchange (ETDEWEB)

Aun, Diego Pinheiro, E-mail: diegoaun@yahoo.com.br [Department of Metallurgical and Materials Engineering, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, 30270-901 Belo Horizonte, MG (Brazil); Houmard, Manuel, E-mail: mhoumard@ufmg.br [Department of Materials and Construction Engineering, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, 30270-901 Belo Horizonte, MG (Brazil); Mermoux, Michel, E-mail: michel.mermoux@lepmi.grenoble-inp.fr [LEPMI, Grenoble INP, rue de la Piscine—BP75 38402, Saint Martin d' Hères (France); Latu-Romain, Laurence, E-mail: laurence.latu-romain@simap.grenoble-inp.fr [SIR Team, Science et Ingénierie des Matériaux et Procédés, Grenoble INP, 1130, rue de la Piscine—BP75 38402, Saint Martin d' Hères (France); Joud, Jean-Charles, E-mail: jean-charles.joud@grenoble-inp.fr [SIR Team, Science et Ingénierie des Matériaux et Procédés, Grenoble INP, 1130, rue de la Piscine—BP75 38402, Saint Martin d' Hères (France); Berthomé, Gregory, E-mail: gregory.berthome@simap.grenoble-inp.fr [SIR Team, Science et Ingénierie des Matériaux et Procédés, Grenoble INP, 1130, rue de la Piscine—BP75 38402, Saint Martin d' Hères (France); Buono, Vicente Tadeu Lopes, E-mail: vbuono@demet.ufmg.br [Department of Metallurgical and Materials Engineering, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, 30270-901 Belo Horizonte, MG (Brazil)

2016-07-01

Highlights: • A NiTi alloy was coated with a flexible TiO{sub 2} protective layer via the sol–gel method. • Maximum flexibility was obtained with a nanocomposite crystalline/amorphous film. • The film reduces the Ni surface content, possibly improving the biocompatibility. - Abstract: An experimental procedure to coat superelastic NiTi alloys with flexible TiO{sub 2} protective nanocomposite films using sol–gel technology was developed in this work to improve the metal biocompatibility without deteriorating its superelastic mechanical properties. The coatings were characterized by scanning and transmission electron microscopy, X-ray photoelectron spectroscopy, Raman spectroscopy, and glazing incidence X-ray diffraction. The elasticity of the film was tested in coated specimens submitted to three-point bending tests. A short densification by thermal treatment at 500 °C for 10 min yielded a bilayer film consisting of a 50 nm-thick crystallized TiO{sub 2} at the inner interface with another 50-nm-thick amorphous oxide film at the outer interface. This bilayer could sustain over 6.4% strain without cracking and could thus be used to coat biomedical instruments as well as other devices made with superelastic NiTi alloys.

Surface plasmon resonances of Ag-Au alloy nanoparticle films grown by sequential pulsed laser deposition at different compositions and temperatures

Energy Technology Data Exchange (ETDEWEB)

Verma, Shweta, E-mail: shwetaverma@rrcat.gov.in; Rao, B. T.; Detty, A. P.; Kukreja, L. M. [Laser Materials Processing Division, Raja Ramanna Centre for Advanced Technology, Indore 452 013 (India); Ganesan, V.; Phase, D. M. [UGC-DAE Consortium for Scientific Research, Indore 452 001 (India); Rai, S. K. [Indus Synchrotons Utilization Division, Raja Ramanna Centre for Advanced Technology, Indore 452 013 (India); Bose, A.; Joshi, S. C. [Proton Linac and Superconducting Cavities Division, Raja Ramanna Centre for Advanced Technology, Indore 452 013 (India)

2015-04-07

We studied localized surface plasmon resonances (LSPR) at different compositions, substrate temperatures, and mass thicknesses of Ag-Au alloy nanoparticle films grown by sequential pulsed laser deposition. The LSPRs were pronounced at all compositions of the films grown at high substrate temperature of about 300 °C as compared to those grown at room temperature. The alloy formation and composition of the films were determined using X-ray photoelectron and energy dispersive spectroscopy. Films' mass thickness and compositional uniformity along the thickness were determined using X-ray reflectometry and secondary ion mass spectroscopy. Atomic force microscopic analysis revealed the formation of densely packed nanoparticles of increasing size with the number of laser ablation pulses. The LSPR wavelength red shifted with increasing either Au percentage or film mass thickness and corresponding LSPR tuning was obtained in the range of 450 to 690 nm. The alloy dielectric functions obtained from three different models were compared and the optical responses of the nanoparticle films were calculated from modified Yamaguchi effective medium theory. The tuning of LSPR was found to be due to combined effect of change in intrinsic and extrinsic parameters mainly the composition, morphology, particle-particle, and particle-substrate interactions.

Preparation of BiOBr thin films with micro-nano-structure and their photocatalytic applications

Energy Technology Data Exchange (ETDEWEB)

Li, Rui [College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Fan, Caimei, E-mail: fancm@163.com [College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Zhang, Xiaochao, E-mail: zhang13598124761@163.com [College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Wang, Yawen; Wang, Yunfang [College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Zhang, Hui [Particle Technology Research Centre, Department of Chemical and Biochemical Engineering, The University of Western Ontario, London, Ontario N6A 5B9 (Canada)

2014-07-01

A series of micro-nano-structure BiOBr thin films were prepared at a low temperature by the alcoholysis-coating method using BiBr{sub 3} as precursor. The as-prepared films were characterized by X-ray powder diffraction, scanning electron microscopy, and Brunauer–Emmett–Teller surface area. The obtained results indicated that micro-nano-structure tetragonal BiOBr films with different intensity ratios of (110) to (102) characteristic peaks could be synthesized through controlling the reaction temperature and the calcination temperatures. Furthermore, the photocatalytic activities of BiOBr thin films with different preparation conditions have been evaluated by the degradation of methyl orange (MO) under UV light irradiation, suggesting that the photocatalytic activity should be closely related to the solvent, the alcoholysis reaction temperature, and the calcining temperature. The best photocatalytic degradation efficiency of MO for BiOBr thin films reaches 98.5% under 2.5 h UV irradiation. The BiOBr thin films display excellent stability and their photocatalytic activity still remains above 90% after being used five times. The main reasons for the higher photocatalytic activity of micro-nano-structure BiOBr microspheres have been investigated. In addition, the possible formation mechanism of BiOBr thin films with micro-nano-structure and excellent photocatalytic activity was proposed and discussed. - Highlights: • The BiOBr film was prepared at low temperature via alcoholysis-coating method. • The optimum process conditions of preparing BiOBr film were discussed. • As-prepared BiOBr films were composed of micro-nano flake structures. • The BiOBr films demonstrated excellent photocatalytic activity. • The formation mechanism of BiOBr films with high activity was proposed.

Study on Preparation and Properties of PVC Film Modified by Rare Earth

Institute of Scientific and Technical Information of China (English)

无

2003-01-01

The transparent PVC films were prepared by tape casting. In the process of preparation, rare earth nitrate, as a kind of modifier, was added to the solution of PVC and THF. These PVC films were tested after being crosslinked by ultraviolet light. It is found that the mechanical and physical properties of all the PVC films modified by rare earth nitrate are greatly enhanced.

Study of the corrosion behavior and the corrosion films formed on the surfaces of Mg–xSn alloys in 3.5 wt.% NaCl solution

International Nuclear Information System (INIS)

Wang, Jingfeng; Li, Yang; Huang, Song; Zhou, Xiaoen

2014-01-01

Highlights: • Corrosion of four cast Mg–xSn alloys in 3.5 wt.% NaCl solution was investigated. • Both Mg(OH) 2 /SnO 2 corrosion product film and Mg(OH) 2 /MgSnO 3 clusters formed on Mg–1.5Sn. • Compact Mg(OH) 2 /MgSnO 3 film suppressed the cathodic effect of the impurity inclusions. • Mg–xSn (x = 0.5, 1.0, 2.0 wt.%) alloys only formed loose Mg(OH) 2 /SnO 2 corrosion product film. - Abstract: The corrosion behavior and the corrosion films formed on the surfaces of Mg–xSn (x = 0.5, 1.0, 1.5, and 2.0 wt.%) alloys in 3.5 wt.% NaCl solution were investigated by immersion tests, electrochemical measurements, corrosion morphology observations, and X-ray diffraction analysis. Immersion tests and electrochemical measurements illustrated that the best corrosion resistance was reported for the Mg–1.5Sn alloy. Both Mg(OH) 2 /SnO 2 corrosion product film and Mg(OH) 2 /MgSnO 3 clusters formed on Mg–1.5Sn alloy surface. Mg(OH) 2 /MgSnO 3 clusters were compact and suppressed the cathodic effect of the impurity inclusions greatly. The Mg–xSn (x = 0.5, 1.0, and 2.0 wt.%) alloys only formed loose Mg(OH) 2 /SnO 2 corrosion product film during the corrosion process

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.

Potentiostatic control of ionic liquid surface film formation on ZE41 magnesium alloy.

Science.gov (United States)

Efthimiadis, Jim; Neil, Wayne C; Bunter, Andrew; Howlett, Patrick C; Hinton, Bruce R W; MacFarlane, Douglas R; Forsyth, Maria

2010-05-01

The generation of potentially corrosion-resistant films on light metal alloys of magnesium have been investigated. Magnesium alloy, ZE41 [Mg-Zn-Rare Earth (RE)-Zr, nominal composition approximately 4 wt % Zn, approximately 1.7 wt % RE (Ce), approximately 0.6 wt % Zr, remaining balance, Mg], was exposed under potentiostatic control to the ionic liquid trihexyl(tetradecyl)phosphonium diphenylphosphate, denoted [P(6,6,6,14)][DPP]. During exposure to this IL, a bias potential, shifted from open circuit, was applied to the ZE41 surface. Electrochemical impedance spectroscopy (EIS) and chronoamperometry (CA) were used to monitor the evolution of film formation on the metal surface during exposure. The EIS data indicate that, of the four bias potentials examined, applying a potential of -200 mV versus OCP during the exposure period resulted in surface films of greatest resistance. Both EIS measurements and scanning electron microscopy (SEM) imaging indicate that these surfaces are substantially different to those formed without potential bias. Time of flight-secondary ion mass spectrometry (ToF-SIMS) elemental mapping of the films was utilized to ascertain the distribution of the ionic liquid cationic and anionic species relative to the microstructural surface features of ZE41 and indicated a more uniform distribution compared with the surface following exposure in the absence of a bias potential. Immersion of the treated ZE41 specimens in a chloride contaminated salt solution clearly indicated that the ionic liquid generated surface films offered significant protection against pitting corrosion, although the intermetallics were still insufficiently protected by the IL and hence favored intergranular corrosion processes.

Effects of Alclad Layer and Anodizing Time on Sulfuric Acid Anodizing and Film Properties of 2E12 Aluminum Alloy

OpenAIRE

CHEN Gao-hong; HU Yuan-sen; YU Mei; LIU Jian-hua; LI Guo-ai

2017-01-01

Alclad and unclad 2E12 aerospace aluminum alloy were treated by sulfuric acid anodic oxidation. The effects of alclad layer and anodizing time on the anodization behaviour and corrosion resistance of anodic oxide layer on 2E12 aluminum alloy were studied. Surface and cross-section morphology of anodic oxide films were observed by scanning electron microscopy. The electrochemical properties of anodic oxide films were analyzed by potentiodynamic polarization curve and electrochemical impedance ...

Polysulfobetaine films prepared by electrografting technique for reduction of biofouling on electroconductive surfaces

International Nuclear Information System (INIS)

Stach, Marek; Kronekova, Zuzana; Kasak, Peter; Kollar, Jozef; Pentrak, Martin; Micusik, Matej; Chorvat, Dusan; Nunney, Tim S.; Lacik, Igor

2011-01-01

The sulfobetaine films were prepared on stainless steel and golden surfaces. In the first step, the poly(2-(dimethylamino)ethyl methacrylate) film was created by employing the electrografting polymerization technique. In the second step, this film was modified to polysulfobetaine, i.e. the polymer film bearing the zwitterionic groups. The presence of the electrografted film and its modification were determined by contact angle measurements, infrared spectroscopy in reflectance mode and X-ray photoelectron spectroscopy. The prepared films were homogeneous with the thickness from about 5 to 26 nm as determined by X-ray photoelectron spectroscopy. The atomic force microscopy measurements showed the increase of surface roughness upon the surface coating. In vitro tests using adherent RAT-2 fibroblast cells and fluorescently labelled bovine serum albumin proteins showed that prepared polysulfobetaine films can be used in applications requiring the resistance against cell attachment and biofouling.

Magnetic properties of magnetic glass-like carbon prepared from furan resin alloyed with magnetic fluid

Energy Technology Data Exchange (ETDEWEB)

Nakamura, Kazumasa, E-mail: naka@sss.fukushima-u.ac.jp [Materials Science Area, Graduate School of Symbiotic Systems Science and Technology, Fukushima University, 1 Kanayagawa, Fukushima 960-1296 (Japan); Okuyama, Kyoko [Materials Science Area, Graduate School of Symbiotic Systems Science and Technology, Fukushima University, 1 Kanayagawa, Fukushima 960-1296 (Japan); Takase, Tsugiko [Institute of Environmental Radioactivity (IER), Fukushima University, 1 Kanayagawa, Fukushima 960-1296 (Japan)

2017-03-01

Magnetic glass-like carbons that were heat-treated at different temperatures or were filled with different magnetic nanoparticle contents were prepared from furan resin alloyed with magnetic fluid (MF) or Fe{sub 3}O{sub 4} powder in their liquid-phase states during mixing. Compared to the Fe{sub 3}O{sub 4} powder-alloyed carbon, the MF-alloyed carbon has highly dispersed the nanoparticles, and has the excellent saturation magnetization and coercivity. It is implied that saturation magnetizations are related to changes in the types of phases for the nanoparticles and the relative intensities of X-ray diffraction peaks for iron and iron-containing compounds in the carbons. Additionally, the coercivities are possibly affected by the size and crystallinity of the nanoparticles, the relative amounts of iron, and the existence of amorphous compounds on the carbon surfaces. - Highlights: • Magnetic glass-like carbons were prepared from furan resin alloyed with magnetic fluid. • The nanoparticles of MF-alloyed GLCs were highly dispersed. • MF-alloyed GLCs had excellent magnetic properties compared to powder-alloyed ones. • The magnetic properties changed with treatment temperature and nanoparticle content. • The changes in magnetic properties were investigated with XRD and FE-SEM.

Preparation and characterization of thick metastable sputter deposits

International Nuclear Information System (INIS)

Allen, R.P.; Dahlgren, S.D.; Merz, M.D.

1975-01-01

High-rate dc supported-discharge sputtering techniques were developed and used to prepare 0.1 mm to 5.0 mm-thick deposits of a variety of metastable materials including amorphous alloys representing more than 15 different rare-earth-transition metal systems and a wide range of compositions and deposition conditions. The ability to prepare thick, homogeneous deposits has made it possible for the first time to investigate the structure, properties, and annealing behavior of these unique sputtered alloys using neutron diffraction, ultrasonic, and other experimental techniques that are difficult or impractical for thin films. More importantly, these characterization studies show that the structure and properties of the massive sputter deposits are independent of thickness and can be reproduced from deposit to deposit. Other advantages and applications of this metastable materials preparation technique include the possibility of varying structure and properties by control of the deposition parameters and the ability to deposit even reactive alloys with a very low impurity content

Quantitative analysis of Si1-xGex alloy films by SIMS and XPS depth profiling using a reference material

Science.gov (United States)

Oh, Won Jin; Jang, Jong Shik; Lee, Youn Seoung; Kim, Ansoon; Kim, Kyung Joong

2018-02-01

Quantitative analysis methods of multi-element alloy films were compared. The atomic fractions of Si1-xGex alloy films were measured by depth profiling analysis with secondary ion mass spectrometry (SIMS) and X-ray Photoelectron Spectroscopy (XPS). Intensity-to-composition conversion factor (ICF) was used as a mean to convert the intensities to compositions instead of the relative sensitivity factors. The ICFs were determined from a reference Si1-xGex alloy film by the conventional method, average intensity (AI) method and total number counting (TNC) method. In the case of SIMS, although the atomic fractions measured by oxygen ion beams were not quantitative due to severe matrix effect, the results by cesium ion beam were very quantitative. The quantitative analysis results by SIMS using MCs2+ ions are comparable to the results by XPS. In the case of XPS, the measurement uncertainty was highly improved by the AI method and TNC method.

Structural and electrochemical behavior of sol-gel ZrO2 ceramic film on chemically pre-treated AZ91D magnesium alloy

International Nuclear Information System (INIS)

Li Qing; Chen Bo; Xu Shuqiang; Gao Hui; Zhang Liang; Liu Chao

2009-01-01

In the present investigation sol-gel-based ZrO 2 ceramic film was obtained using zirconium acetate as the precursor material. The film was deposited on AZ91D magnesium alloy by a dip-coating technique. An uniform stannate conversion coating as chemical pretreatment was employed as an intermediate layer prior to deposition of the ZrO 2 film in order to provide advantage for the formation of sol-gel-based ZrO 2 layer. The corrosion properties, structure, composition and morphology of these coatings on AZ91D magnesium alloy were studied by potentiodynamic polarization tests, EIS, XRD, SEM, respectively. According to the electrochemical tests, the corrosion resistance of AZ91D magnesium alloy was found to be greatly improved by means of this new environment-friendly surface treatment.

Rare earths and rare earth alloys electrolytic preparation process and device for this process

International Nuclear Information System (INIS)

Seon, F.; Barthole, G.

1986-01-01

Electrolysis of a molten salt of rare earth or rare earth alloy for preparation of the metal or alloy is described. The molten salt bath comprises at least a rare earth chloride, at least an alkaline or alkaline earth chloride and at least an alkaline or alkaline earth fluoride [fr

Indium oxide-based transparent conductive films deposited by reactive sputtering using alloy targets

Science.gov (United States)

Miyazaki, Yusuke; Maruyama, Eri; Jia, Junjun; Machinaga, Hironobu; Shigesato, Yuzo

2017-04-01

High-quality transparent conductive oxide (TCO) films, Sn-doped In2O3 (ITO) and In2O3-ZnO (IZO), were successfully deposited on either synthetic silica or polyethylene terephthalate (PET) substrates in the “transition region” by reactive dc magnetron sputtering using In-Zn and In-Sn alloy targets, respectively, with a specially designed plasma emission feedback system. The composition, crystallinity, surface morphology, and electrical and optical properties of the films were analyzed. All of the IZO films were amorphous, whereas the ITO films were polycrystalline over a wide range of deposition conditions. The minimum resistivities of the IZO and ITO films deposited on the heated PET substrates at 150 °C were 3.3 × 10-4 and 5.4 × 10-4 Ω·cm, respectively. By applying rf bias to unheated PET substrates, ITO films with a resistivity of 4.4 × 10-4 Ω·cm were deposited at a dc self-bias voltage of -60 V.

Preparation of Ni-Fe bimetallic porous anode support for solid oxide fuel cells using LaGaO{sub 3} based electrolyte film with high power density

Energy Technology Data Exchange (ETDEWEB)

Ju, Young-Wan; Ida, Shintaro; Ishihara, Tatsumi [Department of Applied Chemistry, Faculty of Engineering, Kyushu University, Motooka 744, Nishi-Ku, Fukuoka 819-0395 (Japan); Eto, Hiroyuki [Mitsubishi Materials Corporation, Central Research Institute, 1002-14 Mukohyama, Naka-Shi, Ibaraki 311-0102 (Japan); Inagaki, Toru [The Kansai Electric Power Co., Inc., 11-20 Nakoji 3-Chome, Amagasaki, Hyogo 661-0974 (Japan)

2010-10-01

Optimization of sintering temperature for NiO-Fe{sub 2}O{sub 3} composite oxide substrate was studied in order to obtain a dense substrate with smooth surface. By in situ reduction, the substrate was changed to a porous Ni-Fe alloy metal. The volumetric shrinkage and porosity of the substrate were also studied systematically with the Ni-Fe substrate reduced at different temperatures. A Sr and Mg-doped LaGaO{sub 3} (LSGM) thin film was prepared on dense substrate by the pulsed laser deposition (PLD) method. The LSGM film with stoichiometric composition was successfully prepared under optimal deposition parameters and a target composition. Sm{sub 0.5}Sr{sub 0.5}CoO{sub 3} (SSC55) cathode was prepared by the slurry coating method on the deposited film. Prepared SOFC single cell shows high power density and the maximum power density (MPD) achieved was 1.79, 0.82 and 0.29 W cm{sup -2} at 973, 873 and 773 K, respectively. After thermal cycle from 973 to 298 K, the cell shows almost theoretical open circuit potential (1.1 V) and the power density of 1.62 W cm{sup -2}, which is almost the same as that at first cycles. Therefore, the Ni-Fe porous metal support made by the selective reduction is highly promising as a metal anode substrate for SOFC using LaGaO{sub 3} thin film. (author)

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.

Optical band gap study of a-Se and Se-Sb thin films

International Nuclear Information System (INIS)

Kaur, Ramandeep; Singh, Palwinder; Thakur, Anup

2016-01-01

Amorphous selenium (a-Se) and a-Se_9_5Sb_5 alloy were prepared using melt quenching technique. X-ray diffraction (XRD) pattern confirmed the amorphous nature of the prepared samples. Composition of the prepared samples has been determined using Energy dispersive X-ray fluorescence (EDXRF) technique. Differential thermal analysis (DTA) confirmed the glassy nature of the prepared samples. Thin films of the prepared samples were deposited on glass substrate using thermal evaporation method. Amorphous nature of the deposited films was confirmed using XRD. Optical properties of these films were obtained from the UV-VIS transmission spectra, at normal incidence, over 200-1100 nm spectral range. The optical absorption edge was described by using the model given by the Tauc. Optical band gap of the deposited films was calculated using Tauc plot. Optical characterization showed that average transmission and optical band gap decreased with the addition of antinomy.

Corrosion behavior of novel imitation-gold copper alloy with rare earth in 3.5% NaCl solution

International Nuclear Information System (INIS)

Chen, J.L.; Li, Z.; Zhu, A.Y.; Luo, L.Y.; Liang, J.

2012-01-01

Highlights: → The design alloy has better anti-tarnish property than that of H7211 alloy during salt-spray test. → The corrosion rate of design alloy is much lower than that of H7211 alloy as immersed in NaCl solution. → In the low frequency region, the capacitive behavior normally faded and diffusion process had a key role. → In the medium frequency region, the Bode pattern showed a capacitive behavior. -- Abstract: A novel imitation-gold copper alloy with rare earth was designed and prepared. The corrosion behavior of the alloy immersed in 3.5% NaCl solution and its anti-tarnish property in the salt spray for different days has been studied. The designed alloy (CuZnAlNiMeRe) has more excellent anti-tarnish property and lower corrosion rate than those of currency coinage materials of H7211 alloy (used in China). A uniform and compact of corrosion film has been formed after the designed alloy immersed in 3.5% NaCl solution. The corrosion current densities I corr of the alloy decreased while the polarization resistance R p increased with time. The capacitance of the corrosion product film C film of the alloy decreased while the charge transfer resistance R ct . The Warburg diffusion impedance W R and the resistance of the equivalent circuit R increased with time.

Hydroxyapatite coatings on titanium dioxide thin films prepared by pulsed laser deposition method

International Nuclear Information System (INIS)

Suda, Yoshiaki; Kawasaki, Hiroharu; Ohshima, Tamiko; Nakashima, Shouta; Kawazoe, Syuichi; Toma, Tetsuya

2006-01-01

Hydroxyapatite (HAp) coated on titanium dioxide (TiO 2 ) thin films has been developed to supplement the defects of both TiO 2 and HAp. Thin films have been prepared by pulsed laser deposition (PLD) method using HAp and HAp(10%) + TiO 2 targets. X-ray diffraction (XRD) shows that there are many small peaks of Ca 1 0(PO 4 ) 6 (OH) 2 crystal, and no impurity other than HAp is detected in HAp films prepared using pure HAp target. The composition ratio of the film was analyzed by X-ray photoelectron spectroscopy (XPS). HAp coatings on TiO 2 thin films have been prepared using HAp(10%) + TiO 2 targets. XRD and XPS measurements suggest that crystalline HAp + TiO 2 thin films are obtained by the PLD method using HAp(10%) + TiO 2 target

Nanocrystalline CdS{sub 1−x}Se{sub x} alloys as thin films prepared by chemical bath deposition: Effect of x on the structural and optical properties

Energy Technology Data Exchange (ETDEWEB)

Sanchez-Ramirez, E.A. [Escuela Superior de Ingeniería Química e Industrias Extractivas, Instituto Politécnico Nacional, CP 07738, México D.F. (Mexico); Hernandez-Perez, M.A., E-mail: mhernandezp0606@ipn.mx [Escuela Superior de Ingeniería Química e Industrias Extractivas, Instituto Politécnico Nacional, CP 07738, México D.F. (Mexico); Aguilar-Hernandez, J. [Escuela Superior de Física y Matemáticas, Instituto Politécnico Nacional, CP 07738, México D.F. (Mexico); Rangel-Salinas, E. [Escuela Superior de Ingeniería Química e Industrias Extractivas, Instituto Politécnico Nacional, CP 07738, México D.F. (Mexico)

2014-12-05

Highlights: • CdS1−xSe{sub x} films with tunable structural and optical properties were grown by CBD. • Thin films are composed by a solid solution of the CdS{sub 1−x}Se{sub x} ternary alloy. • Crystal size, band gap and photoluminescence signal, decrease with the composition. • Ternary alloys show hexagonal phase with preferential orientation on (0 0 2) plane. • Films with x ⩾ 0.5 show semi-spherical grains composed by nanoworms structures. - Abstract: CdS{sub 1−x}Se{sub x} thin films were deposited on Corning glass substrates at 75 °C by chemical bath deposition (CBD) varying the composition “x” from 0 to 1 at a constant deposition time of 120 min. The composition of the films was adjusted by modifying the concentration as well as the ratio of the precursors. The morphological, compositional, structural and optical properties of the films were analyzed using several techniques such as Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), X-ray Diffraction (XRD), UV–Vis Spectroscopy (UV–Vis) and Photoluminescence (PL). The films grow as layers following the ion by ion mechanism, the density of the films decreases with x. Films are constituted by clusters (100–600 nm in diameter) of semispherical particles with sizes fluctuating from 10 to 20 nm. For x ⩾ 0.5 the particles are well-arranged in a “worm-like” structure. All the films are polycrystalline, to x = 0 (CdS) the cubic phase is present, the increase of composition promotes the formation of hexagonal phase or a mixture of both cubic and hexagonal phases. Preferential orientation in the (1 0 0) or (0 0 2) plane is observed. The crystal size decreases from 20 to 6 nm when x is increased. The optical properties can be easily tuned by adjusting the composition. Optical absorption analysis shows that the band gap (E{sub g}) value shifts to red in function of x (from 2.47 to 1.99 eV). Photoluminescence signal changes as “x” varies showing a regular behavior

Orbital hybridization, crystal structure and anomalous resistivity of ultrathin CrZrx alloy films on polymeric substrates

International Nuclear Information System (INIS)

Evans, Drew; Zuber, Kamil; Merkens, Kerstin; Murphy, Peter

2012-01-01

The orbital hybridization and crystal structure are experimentally explored for ultrathin chrome zirconium (CrZr x ) alloy films co-sputtered on precoated polymeric substrates. We determine the level of orbital hybridization and crystal structure using X-ray photoelectron spectroscopy and electron diffraction. Body-centred cubic and Ω-hexagonally close-packed phases are observed to coexist in the sputtered Cr-based films. Experiments reveal the orbital hybridization and crystal structure combine to produce anomalous resistivity for these ultrathin films.

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. Copyright © 2016 Elsevier Ltd. All rights reserved.

Preparation of anatase TiO2 thin films by vacuum arc plasma evaporation

International Nuclear Information System (INIS)

Miyata, Toshihiro; Tsukada, Satoshi; Minami, Tadatsugu

2006-01-01

Anatase titanium dioxide (TiO 2 ) thin films with high photocatalytic activity have been prepared with deposition rates as high as 16 nm/min by a newly developed vacuum arc plasma evaporation (VAPE) method using sintered TiO 2 pellets as the source material. Highly transparent TiO 2 thin films prepared at substrate temperatures from room temperature to 400 deg. C exhibited photocatalytic activity, regardless whether oxygen (O 2 ) gas was introduced during the VAPE deposition. The highest photocatalytic activity and photo-induced hydrophilicity were obtained in anatase TiO 2 thin films prepared at 300 deg. C, which correlated to the best crystallinity of the films, as evidenced from X-ray diffraction. In addition, a transparent and conductive anatase TiO 2 thin film with a resistivity of 2.6 x 10 -1 Ω cm was prepared at a substrate temperature of 400 deg. C without the introduction of O 2 gas

Review of WO3 thin film preparation for photoelectrochemical water splitting

International Nuclear Information System (INIS)

Ehsan Eftekhari; Mohammad Kassim

2009-01-01

Full text: Tungsten trioxide (WO 3 ), which is one of the most essential materials in our daily life has appeared as an excellent photo electrode material for environmental purification. The nano-size of WO 3 thin film water-splitting technology has great potential for environmentally friendly solar-hydrogen production for the future hydrogen economy. There are several methods for producing tungsten oxide film. In this review, we outlined several WO 3 thin film preparation methods such as doctor Bladding, sputtering, layer-by-layer brush painting, spray pyrolysis deposition, sol-gel and other methods. Here we compare the maximum photocurrent obtained, different condition for preparation of WO 3 thin film and characterization outcome. (author)

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.

Preparation of YBCO superconducting films by spray pyrolysis method

International Nuclear Information System (INIS)

Mora Alonso, M.; Leyva Fabelo, A.; Rubio Frias, E.; Pupo Gonzalez, I.; Lopez Sanchez, D.

1994-01-01

The methodology for the preparation of YBCO superconducting films on Zr 2O (Y) substrates by spray pyrolysis method is reported. The transition temperature of these films is superior than the boiling temperature of liquid 2N . Other critical parameters are similar to those reported by other authors using the same technique

Challenges of sample preparation for cross sectional EBSD analysis of electrodeposited nickel films

DEFF Research Database (Denmark)

Alimadadi, Hossein; Pantleon, Karen

2009-01-01

Thorough microstructure and crystallographic orientation analysis of thin films by means of electron backscatter diffraction requires cross section preparation of the film-substrate compound. During careful preparation, changes of the rather non-stable as-deposited microstructure must be avoided....... Different procedures for sample preparation including mechanical grinding and polishing, electropolishing and focused ion beam milling have been applied to a nickel film electrodeposited on top of an amorphous Ni-P layer on a Cu-substrate. Reliable EBSD analysis of the whole cross section can be obtained...

Preparation of poly(vinylbenzyl chloride)-grafted PFA film by a simultaneous irradiation grafting method

International Nuclear Information System (INIS)

Fei, Geng; Shin, Jun Hwa; Nho, Young Chang; Lee, Youn Sik

2009-01-01

In this study, PFA-g-PVBC films were prepared by a radiation grafting of vinylbenzyl chloride (VBC) monomer onto poly(tetrafluoroethylene-co-perfluoro propyl vinyl ether) (PFA) films by simultaneous irradiation method. IR, TGA, and SEM-EDX instruments were utilized to confirm the successful preparation of the grafted film. The effects of several irradiation conditions, including the dose, VBC concentration, and film thickness on the degree of grafting of PFA-g-PVBC film were investigated

On the response of alloyed ZnCdSeS quantum dot films

Directory of Open Access Journals (Sweden)

I. Valais

Full Text Available The aim of this work was to prepare composite ZnCdSeS quantum dot (QD flexible films and to examine their optical properties under ultraviolet excitation. PMMA/QD ZnCdSeS composite films, with emission covering the visual spectrum (480–630 nm were prepared with concentrations 10 mg/mL and 20 mg/mL by homogenously diluting dry powder QD samples in toluene and subsequently mixing with a PMMA/MMA polymer solution to the final ZnCdSeS/Toluene mixture. Scanning electron microscopy (SEM images of the produced films were obtained. The ZnCdSeS films were excited by ultraviolet light of varying intensities and the spectral matching with various optical detectors was estimated.

Preparation and Evaluation of Buccal Bioadhesive Films Containing Clotrimazole

OpenAIRE

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...

Adhesive B-doped DLC films on biomedical alloys used for bone

Indian Academy of Sciences (India)

The addition of a thin interfacial layer such as Si, Ti, TiN, Mo and Cu/Cr and/or adding additives such as Si, F, N, O, W, V, Co, Mo, Ti or their combinations to the DLC films has been found to increase the adhesion strength substantially. In our study, grade 316L stainless steel and grade 5 titanium alloy (Ti–6Al–4V) were used ...

Preparation and characterization of depolymerised chitosan films and crosslinked with sodium tripolyphosphate

International Nuclear Information System (INIS)

Salazar, Max Carlos; Valderrama Negron, Ana

2013-01-01

This work has studied the preparation and characterization of chitosan films (CS) crosslinked with sodium tripolyphosphate (TPP), prepared by the solvent evaporation method. Initially we studied the depolymerization of chitosan with sodium nitrite to get different polymer molecular weights in the used polymer. For example, we obtained chitosans of 554.22kDa and 133.37kDa of molecular weight. Afterward, prepared and characterized chitosans films crosslinked with TPP, evidently the hydrogen bridge interaction with the polyanion through IR, SEM, TG; also was performed swelling studies, with the objective of identified the type of kinetic model in which enable explain said phenomenon in these films. (author)

Microstructure and Properties of Selected Magnesium-Aluminum Alloys Prepared for SPD Processing Technology

Directory of Open Access Journals (Sweden)

Cizek L.

2017-12-01

Full Text Available A growing interest in wrought magnesium alloys has been noticed recently, mainly due to development of various SPD (severe plastic deformation methods that enable significant refinement of the microstructure and – as a result – improvement of various functional properties of products. However, forming as-cast magnesium alloys with the increased aluminum content at room temperature is almost impossible. Therefore, application of heat treatment before forming or forming at elevated temperature is recommended for these alloys. The paper presents the influence of selected heat treatment conditions on the microstructure and the mechanical properties of the as-cast AZ91 alloy. Deformation behaviour of the as-cast AZ61 alloy at elevated temperatures was analysed as well. The microstructure analysis was performed by means of both light microscopy and SEM. The latter one was used also for fracture analysis. Moreover, the effect of chemical composition modification by lithium addition on the microstructure of the AZ31-based alloy is presented. The test results can be helpful in preparation of the magnesium-aluminum alloys for further processing by means of SPD methods.

Nonlinear Analysis of Actuation Performance of Shape Memory Alloy Composite Film Based on Silicon Substrate

Directory of Open Access Journals (Sweden)

Shuangshuang Sun

2014-01-01

Full Text Available The mechanical model of the shape memory alloy (SMA composite film with silicon (Si substrate was established by the method of mechanics of composite materials. The coupled action between the SMA film and Si substrate under thermal loads was analyzed by combining static equilibrium equations, geometric equations, and physical equations. The material nonlinearity of SMA and the geometric nonlinearity of bending deformation were both considered. By simulating and analyzing the actuation performance of the SMA composite film during one cooling-heating thermal cycle, it is found that the final cooling temperature, boundary condition, and the thickness of SMA film have significant effects on the actuation performance of the SMA composite film. Besides, the maximum deflection of the SMA composite film is affected obviously by the geometric nonlinearity of bending deformation when the thickness of SMA film is very large.

Electrochemical deposition of Mg(OH2/GO composite films for corrosion protection of magnesium alloys

Directory of Open Access Journals (Sweden)

Fengxia Wu

2015-09-01

Full Text Available Mg(OH2/graphene oxide (GO composite film was electrochemical deposited on AZ91D magnesium alloys at constant potential. The characteristics of the Mg(OH2/GO composite film were investigated by scanning electron microscope (SEM, energy-dispersive X-ray spectrometry (EDS, X-ray diffractometer (XRD and Raman spectroscopy. It was shown that the flaky GO randomly distributed in the composite film. Compared with the Mg(OH2 film, the Mg(OH2/GO composite film exhibited more uniform and compact structure. Potentiodynamic polarization tests revealed that the Mg(OH2/GO composite film could significantly improve the corrosion resistance of Mg(OH2 film with an obvious positive shift of corrosion potential by 0.19 V and a dramatic reduction of corrosion current density by more than one order of magnitude.

Morphology and performances of the anodic oxide films on Ti6Al4V alloy formed in alkaline-silicate electrolyte with aminopropyl silane addition under low potential

International Nuclear Information System (INIS)

Chen, Jiali; Wang, Jinwei; Yuan, Hongye

2013-01-01

Oxide films on Ti6Al4V alloy are prepared using sodium hydroxide–sodium silicate as the base electrolyte with addition of aminopropyl trimethoxysilane (APS) as additive by potentiostatic anodizing under 10 V. APS is incorporated into the films during anodizing and the surface morphology of the oxide films is changed from particle stacked to honeycomb-like porous surfaces as shown by scanning electron microscopy (SEM) with Energy Disperse Spectroscopy (EDX). The surface roughness and aminopropyl existence on the oxide films result in their differences in wettability as tested by the surface profile topography and contact angle measurements. The anti-abrasive ability of the anodic films is improved with the addition of APS due to its toughening effects and serving as lubricants in the ceramic oxide films as measured by ball-on-disk friction test. Also, potentiodynamic corrosion test proves that their anticorrosive ability in 3.5 wt.% NaCl is greatly improved as reflected by their much lower corrosion current (I corr ) and higher corrosion potential (E corr ) than those of the substrate.

Morphology and performances of the anodic oxide films on Ti6Al4V alloy formed in alkaline-silicate electrolyte with aminopropyl silane addition under low potential

Energy Technology Data Exchange (ETDEWEB)

Chen, Jiali; Wang, Jinwei, E-mail: wangjw@ustb.edu.cn; Yuan, Hongye

2013-11-01

Oxide films on Ti6Al4V alloy are prepared using sodium hydroxide–sodium silicate as the base electrolyte with addition of aminopropyl trimethoxysilane (APS) as additive by potentiostatic anodizing under 10 V. APS is incorporated into the films during anodizing and the surface morphology of the oxide films is changed from particle stacked to honeycomb-like porous surfaces as shown by scanning electron microscopy (SEM) with Energy Disperse Spectroscopy (EDX). The surface roughness and aminopropyl existence on the oxide films result in their differences in wettability as tested by the surface profile topography and contact angle measurements. The anti-abrasive ability of the anodic films is improved with the addition of APS due to its toughening effects and serving as lubricants in the ceramic oxide films as measured by ball-on-disk friction test. Also, potentiodynamic corrosion test proves that their anticorrosive ability in 3.5 wt.% NaCl is greatly improved as reflected by their much lower corrosion current (I{sub corr}) and higher corrosion potential (E{sub corr}) than those of the substrate.

The Preparation and Property of Graphene /Tin Oxide Transparent Conductive Film

Directory of Open Access Journals (Sweden)

SUN Tao

2017-02-01

Full Text Available Graphene doped tin oxide composites were prepared with SnCIZ·2HZ 0 and graphene oxide as raw materials with sol-gel method and then spincoated on the quartz glass to manufacture a new transparent conductive film. The composite film was characterized with X-ray diffraction(XRDand scanning electron microscopy(SEM analysis. XRD results show that the graphene oxide was successfully prepared with Hummers method. The graphene layers and particulate SnOZ can be clearly observed in SEM photos. The transmittance and conductivity of the thin films were tested with ultraviolet visible spectrophotometer and Hall effect measurement. The results show that the transmittivity of composite film in visible region is more than 90% and surface square resistance is 41 S2/口.The graphene/ SnOZ film exhibits a higher performance in transparence and conductivity than commercial FTO glass.

Corrosion resistant zirconium alloys prepared by powder metallurgy

International Nuclear Information System (INIS)

Wojeik, C.C.

1984-01-01

Pure zirconium and zirconium 2.5% niobium were prepared by powder metallurgy. The powders were prepared directly from sponge and consolidated by cold isostatic pressing and sintering. Hot isostatic pressing was also used to obtain full density after sintering. For pure zirconium the effects of particle size, compaction pressure, sintering temperature and purity were investigated. Fully densified zirconium and Zr-2.5%Nb exhibited tensile properties comparable to cast material at room temperature and 300 0 F (149 0 C). Pressed and sintered material having density of 94-99% had slightly lower tensile properties. Corrosion tests were performed in boiling 65% H/sub 2/SO/sub 4/, 70% HNO/sub 3/, 20% HCl and 20% HCl + 500 ppm FeCl/sub 3/ (a known pitting solution). For fully dense material the observed corrosion behavior was nearly equivalent to cast material. A slightly higher rate of attack was observed for samples which were only 94-99% dense. Welding tests were also performed on zirconium and Zr-2.5%Nb alloy. Unlike P/M titanium alloys, these materials had good weldability due to the lower content of volatile impurities in the powder. A slight amount of weld porosity was observed but joint efficiencies were always not 100%, even for 94-99% density samples. Several practical applications of the P/M processed material will be briefly described

Read/write characteristics of a new type of bit-patterned-media using nano-patterned glassy alloy

International Nuclear Information System (INIS)

Takenaka, Kana; Saidoh, Noriko; Nishiyama, Nobuyuki; Ishimaru, Manabu; Futamoto, Masaaki; Inoue, Akihisa

2012-01-01

The paper reports a feasibility study of new type bit-patterned-media using a nano-patterned glassy alloy template for ultra-high density hard disk applications. The prototype bit-patterned-media was prepared using a nano-hole array pattern fabricated on a Pd-based glassy alloy thin film and a Co/Pd multilayered film filled in the nano-holes. The prepared prototype bit-patterned-media had a smooth surface and isolated Co/Pd multilayer magnetic dots, where the average dot diameter, the average dot pitch and the average dot height were 30, 60 and 19 nm, respectively. MFM (magnetic force microscope) observation revealed that each dot was magnetized in a perpendicular direction and the magnetization could reverse when an opposite magnetic field was applied. Static read/write tester measurements showed that repeated writing and reading on isolated magnetic dots were possible in combination with conventional magnetic heads and high-accuracy positioning technologies. The present study indicates that the new type of bit-patterned-media composed of nano-hole arrays fabricated on glassy alloy film template and Co/Pd multilayer magnetic dots are promising for applications to next generation ultra-high density hard disk drives. - Highlights: ► Prototype BPM using a nano-hole array pattern of imprinted Pd-based glassy alloy thin film and Co/Pd multilayered film was set. ► The prototype BPM has smooth surface and isolated Co/Pd multilayer magnetic dots with an average dot diameter of 30 nm. ► Dots acted as perpendicular magnetic dot and were able to read, erase and write in a row by a usual perpendicular magnetic head.

Investigation of phase stability of novel equiatomic FeCoNiCuZn based-high entropy alloy prepared by mechanical alloying

Science.gov (United States)

Soni, Vinay Kumar; Sanyal, S.; Sinha, S. K.

2018-05-01

The present work reports the structural and phase stability analysis of equiatomic FeCoNiCuZn High entropy alloy (HEA) systems prepared by mechanical alloying (MA) method. In this research effort some 1287 alloy combinations were extensively studied to arrive at most favourable combination. FeCoNiCuZn based alloy system was selected on the basis of physiochemical parameters such as enthalpy of mixing (ΔHmix), entropy of mixing (ΔSmix), atomic size difference (ΔX) and valence electron concentration (VEC) such that it fulfils the formation criteria of stable multi component high entropy alloy system. In this context, we have investigated the effect of novel alloying addition in view of microstructure and phase formation aspect. XRD plots of the MA samples shows the formation of stable solid solution with FCC (Face Cantered Cubic) after 20 hr of milling time and no indication of any amorphous or intermetallic phase formation. Our results are in good agreement with calculation and analysis done on the basis of physiochemical parameters during selection of constituent elements of HEA.

Enhanced magnetostriction derived from magnetic single domain structures in cluster-assembled SmCo films

Science.gov (United States)

Bai, Yulong; Yang, Bo; Guo, Fei; Lu, Qingshan; Zhao, Shifeng

2017-11-01

Cluster-assembled SmCo alloy films were prepared by low energy cluster beam deposition. The structure, magnetic domain, magnetization, and magnetostriction of the films were characterized. It is shown that the as-prepared films are assembled in compact and uniformly distributed spherical cluster nanoparticles, most of which, after vacuum in situ annealing at 700 K, aggregated to form cluster islands. These cluster islands result in transformations from superparamagnetic states to magnetic single domain (MSD) states in the films. Such MSD structures contribute to the enhanced magnetostrictive behaviors with a saturation magnetostrictive coefficient of 160 × 10-6 in comparison to 105 × 10-6 for the as-prepared films. This work demonstrates candidate materials that could be applied in nano-electro-mechanical systems, low power information storage, and weak magnetic detecting devices.

Antimony sulfide thin films prepared by laser assisted chemical bath deposition

International Nuclear Information System (INIS)

Shaji, S.; Garcia, L.V.; Loredo, S.L.; Krishnan, B.

2017-01-01

Highlights: • Antimony sulfide thin films were prepared by normal 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. • These films were photoconductive. - Abstract: Antimony sulfide (Sb_2S_3) thin films were prepared by laser assisted chemical bath deposition (LACBD) technique. These thin films were deposited on glass substrates from a chemical bath containing antimony chloride, acetone and sodium thiosulfate under various conditions of normal chemical bath deposition (CBD) as well as in-situ irradiation of the chemical bath using a continuous laser of 532 nm wavelength. Structure, composition, morphology, optical and electrical properties of the Sb_2S_3 thin films produced by normal CBD and LACBD were analyzed by X-Ray diffraction (XRD), Raman Spectroscopy, Atomic force microscopy (AFM), X-Ray photoelectron spectroscopy (XPS), UV–vis spectroscopy and Photoconductivity. The results showed that LACBD is an effective synthesis technique to obtain Sb_2S_3 thin films for optoelectronic applications.

Antimony sulfide thin films prepared by laser assisted chemical bath deposition

Energy Technology Data Exchange (ETDEWEB)

Shaji, S., E-mail: sshajis@yahoo.com [Facultad de Ingeniería Mecánica y Eléctrica, Universidad Autónoma de Nuevo León, Av. Pedro de Alba s/n, Ciudad Universitaria, San Nicolás de los Garza, Nuevo León, 66455 (Mexico); CIIDIT—Universidad Autónoma de Nuevo León, Apodaca, Nuevo León (Mexico); Garcia, L.V. [Facultad de Ingeniería Mecánica y Eléctrica, Universidad Autónoma de Nuevo León, Av. Pedro de Alba s/n, Ciudad Universitaria, San Nicolás de los Garza, Nuevo León, 66455 (Mexico); Loredo, S.L. [Centro de Investigación en Materiales Avanzados (CIMAV), Unidad Monterrey, PIIT, Apodaca, Nuevo León (Mexico); Krishnan, B. [Facultad de Ingeniería Mecánica y Eléctrica, Universidad Autónoma de Nuevo León, Av. Pedro de Alba s/n, Ciudad Universitaria, San Nicolás de los Garza, Nuevo León, 66455 (Mexico); CIIDIT—Universidad Autónoma de Nuevo León, Apodaca, Nuevo León (Mexico); and others

2017-01-30

Highlights: • Antimony sulfide thin films were prepared by normal 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. • These films were photoconductive. - Abstract: Antimony sulfide (Sb{sub 2}S{sub 3}) thin films were prepared by laser assisted chemical bath deposition (LACBD) technique. These thin films were deposited on glass substrates from a chemical bath containing antimony chloride, acetone and sodium thiosulfate under various conditions of normal chemical bath deposition (CBD) as well as in-situ irradiation of the chemical bath using a continuous laser of 532 nm wavelength. Structure, composition, morphology, optical and electrical properties of the Sb{sub 2}S{sub 3} thin films produced by normal CBD and LACBD were analyzed by X-Ray diffraction (XRD), Raman Spectroscopy, Atomic force microscopy (AFM), X-Ray photoelectron spectroscopy (XPS), UV–vis spectroscopy and Photoconductivity. The results showed that LACBD is an effective synthesis technique to obtain Sb{sub 2}S{sub 3} thin films for optoelectronic applications.

Glow discharge preparation and electrooptical characterisation of amorphous silicon alloys for solar cells. Preparacion por descarga luminiscente y caracterizacion electrooptica de aleaciones de silicio amorfo para celulas solares

Energy Technology Data Exchange (ETDEWEB)

Carabe, J

1990-11-01

A study is presented, focused on the preparation and characterisation of hydrogenated amorphous silicon alloy thin films for their application as p type window layers in pin silicon solar cells. The preparation technique used was radio frequency glow discharge. The samples were characterised optically (visible, near infrared and infrared absorption spectrophotometry) and electrically (dark and photoconductivities at ambient temperature and as functions of temperature). The influence of each of the preparation parameters on film properties has been systematically studied. The results have been analysed according to the existing models. Chapter 1 is an introduction to the material in question and its photovoltaic applications. Chapter 2 describes the experimental procedure used. Capter 3 shows and discusses the most relevant results obtained in the study of intrinsic amorphous silicon, p type amorphous silicon and p type amorphous silicon carbide window layers, with special emphasis on the influence of the use of an alternative dopant gas: boron trifluoride. Finally, chapter 4 summarises the most relevant conclusions drawn from this research work. (Author)

Texture control and growth mechanism of WSe{sub 2} film prepared by rapid selenization of W film

Energy Technology Data Exchange (ETDEWEB)

Li, Hongchao [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); Chongyi Zhangyuan Tungsten Industry Corporation Limited, Ganzhou 341300 (China); Gao, Di; Li, Kun; Pang, Mengde; Xie, Senlin [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); Liu, Rutie, E-mail: llrrtt@csu.edu.cn [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); Zou, Jianpeng [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China)

2017-02-01

Highlights: • We present a highly efficient method for preparing WSe{sub 2} film by rapid selenization. • The W film phase composition has little effect on WSe{sub 2} film orientation. • W film density is a critical factor that influences the WSe{sub 2} orientation. • A growth model was proposed for two kinds of WSe{sub 2} film textures. - Abstract: The tungsten diselenide (WSe{sub 2}) films with different orientation present unique properties suitable for specific applications, such as WSe{sub 2} with a C-axis⊥substrate for optoelectronics and WSe{sub 2} with a C-axis // substrate for electrocatalysts. Orientation control of WSe{sub 2} is essential for realizing the practical applications. In this letter, a WSe{sub 2} film has been prepared via rapid selenization of a magnetron-sputtered tungsten (W) film. The influence of the magnetron-sputtered W film on WSe{sub 2} 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 WSe{sub 2} films. The substrate temperature has a significant effect on the W film phase composition, but little effect on the WSe{sub 2} film orientation. The WSe{sub 2} 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 WSe{sub 2} with a C-axis⊥substrate, whereas a porous W film deposited at high pressure favors the formation of WSe{sub 2} with a C-axis // substrate. A growth model for the WSe{sub 2} 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 WSe{sub 2} films. Highly oriented WSe{sub 2} films with a C-axis⊥substrate grow from the dense W film deposited at low pressure because Se vapor

Preparation and characterization of ultra-thin sol-gel films

International Nuclear Information System (INIS)

Shapiro, Leora; Marx, Sharon; Mandler, Daniel

2007-01-01

The formation and characterization of nanometer thick sol-gel films are reported. The films were prepared by spin-coating of a diluted solution of a silane precursor on a number of different substrates. The effect of dilution, rotation speed and nature of substrate on the thickness and homogeneity of the films was examined. Characterization of the films was carried out by profilometry, reflectance spectroscopy, atomic force microscopy, adhesion test and electrochemistry. We find that the dilution factor has a pronounced effect on the film thickness. Moreover, the time of dilution, namely, whether dilution was carried out before or after a period of hydrolysis, has a noticeable effect on the thickness as well as on the permeability of embedded species

Preparation and characterization of the micro-arc oxidation composite coatings on magnesium alloys

OpenAIRE

Yanfeng Ge; Bailing Jiang; Ming Liu; Congjie Wang; Wenning Shen

2014-01-01

The magnesium alloys attract the light-weight manufacture due to its high strength to weight ratio, however the poor corrosion resistance limits the application in automobile industry. The Micro-arc Composite Ceramic (MCC) coatings on AZ91D magnesium alloys were prepared by Micro-arc Oxidation (MAO) and electrophoresis technologies. The microstructure, corrosion resistance, abrasion resistance, stone impact resistance and adhesion of MCC coatings were studied respectively. The cross section m...

Ultrahigh hardness and high electrical resistivity in nano-twinned, nanocrystalline high-entropy alloy films

Science.gov (United States)

Huo, Wenyi; Liu, Xiaodong; Tan, Shuyong; Fang, Feng; Xie, Zonghan; Shang, Jianku; Jiang, Jianqing

2018-05-01

Nano-twinned, nanocrystalline CoCrFeNi high-entropy alloy films were produced by magnetron sputtering. The films exhibit a high hardness of 8.5 GPa, the elastic modulus of 161.9 GPa and the resistivity as high as 135.1 μΩ·cm. The outstanding mechanical properties were found to result from the resistance of deformation created by nanocrystalline grains and nano-twins, while the electrical resistivity was attributed to the strong blockage effect induced by grain boundaries and lattice distortions. The results lay a solid foundation for the development of advanced films with structural and functional properties combined in micro-/nano-electronic devices.

Effects of single pulse energy on the properties of ceramic coating prepared by micro-arc oxidation on Ti alloy

Energy Technology Data Exchange (ETDEWEB)

Wang, Jun-Hua [Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China); School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471023 (China); Faculty of Mechanical and Electrical Engineering, Kunming University of Science and Technology, Kunming 650500 (China); Wang, Jin [Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China); Beijing Key Lab of Precision/Ultra-precision Manufacturing Equipments and Control, Beijing 100084 (China); Lu, Yan [School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471023 (China); Du, Mao-Hua [Faculty of Mechanical and Electrical Engineering, Kunming University of Science and Technology, Kunming 650500 (China); Han, Fu-Zhu, E-mail: hanfuzhu@mail.tsinghua.edu.cn [Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China); Beijing Key Lab of Precision/Ultra-precision Manufacturing Equipments and Control, Beijing 100084 (China)

2015-01-01

Highlights: • Single pulse energy remarkably influences the properties of ceramic coating prepared by MAO on Ti alloy. • The accumulative time of impulse width is an important parameter in the scientific and rational measurement of the film forming law of ceramic coating. • The ceramic coating thickness approximately linearly increases with the cumulative time of impulse width. • Larger impulse width resulted in higher single pulse energy, film forming rates and thicker ceramic coating thickness. • The effects of single pulse energy on the micro-hardness and phase composition of ceramic coating are not as evident as those of frequency and duty cycle. - Abstract: The effects of single pulse energy on the properties of ceramic coating fabricated on a Ti–6Al–4V alloy via micro-arc oxidation (MAO) in aqueous solutions containing aluminate, phosphate, and some additives are investigated. The thickness, micro-hardness, surface and cross-sectional morphology, surface roughness, and compositions of the ceramic coating are studied using eddy current thickness meter, micro-hardness tester, JB-4C Precision Surface roughness meter, scanning electron microscopy (SEM) and X-ray diffraction (XRD). Single pulse energy remarkably influences the ceramic coating properties. The accumulative time of impulse width is an important parameter in the scientific and rational measurement of the film forming law of ceramic coating. The ceramic coating thickness approximately linearly increases with the cumulative time of impulse width. Larger impulse width resulted in higher single pulse energy, film forming rates and thicker ceramic coating thickness. The sizes of oxide particles, micro-pores and micro-cracks slightly increase with impulse width and single pulse energy. The main surface conversion products generated during MAO process in aqueous solutions containing aluminate are rutile TiO{sub 2}, anatase TiO{sub 2}, and a large amount of Al{sub 2}TiO{sub 5}. The effects of

Deposition of CuIn(Se,S)2 thin films by sulfurization of selenized Cu/In alloys

International Nuclear Information System (INIS)

Sheppard, C.J.; Alberts, V.; Bekker, W.J.

2004-01-01

The relatively small band gap values (close to 1eV) of CuInSe 2 thin films limits the conversion efficiencies of completed CuInSe 2 /CdS/ZnO solar cell devices. In the case of traditional two-stage growth techniques, limited success has been achieved to increase the band gap by substituting indium with gallium. In this study, sputtered copper-indium alloys were exposed to a H 2 Se/Ar atmosphere under defined conditions in order to produce partially reacted CuInSe 2 structures. These films were subsequently exposed to a H 2 S/Ar atmosphere to produce monophasic CuIn(Se, S) 2 quaternary alloys. The homogeneous incorporation of S into CuInSe 2 led to a systematic shift in the lattice parameters and band gap of the ab- sorber films. From these studies optimum selenization/sulfurization conditions were determined for the deposition of homogeneous CuIn(Se,S) 2 thin films with an optimum band gap values between 1.15 and 1.2 eV. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Anodic oxidation of Ta/Fe alloys

International Nuclear Information System (INIS)

Mato, S.; Alcala, G.; Thompson, G.E.; Skeldon, P.; Shimizu, K.; Habazaki, H.; Quance, T.; Graham, M.J.; Masheder, D.

2003-01-01

The behaviour of iron during anodizing of sputter-deposited Ta/Fe alloys in ammonium pentaborate electrolyte has been examined by transmission electron microscopy, Rutherford backscattering spectroscopy, glow discharge optical emission spectroscopy and X-ray photoelectron spectroscopy. Anodic films on Ta/1.5 at.% Fe, Ta/3 at.% Fe and Ta/7 at.% Fe alloys are amorphous and featureless and develop at high current efficiency with respective formation ratios of 1.67, 1.60 and 1.55 nm V -1 . Anodic oxidation of the alloys proceeds without significant enrichment of iron in the alloy in the vicinity of the alloy/film interface and without oxygen generation during film growth, unlike the behaviour of Al/Fe alloys containing similar concentrations of iron. The higher migration rate of iron species relative to that of tantalum ions leads to the formation of an outer iron-rich layer at the film surface

The preparation of ZnO based gas-sensing thin films by ink-jet printing method

International Nuclear Information System (INIS)

Shen Wenfeng; Zhao Yan; Zhang Caibei

2005-01-01

An ink-jet printing technique was applied to prepare ZnO based gas-sensing thin films. ZnO inks with appropriate viscosity and surface tension were prepared by sol-gel techniques, and printed onto substrates using a commercial printer. After the drying and heating treatment processes, continuous ZnO films were formed and studied by scanning electron microscopy, X-ray diffraction and by a home-made gas sensitivity measuring system. It was found that the morphology and electrical properties of the films changed significantly with the thickness of the films, which can be adjusted simply by printing on the film with increasing frequency. Highest resistance and sensitivity to acetone vapor were obtained when the film was prepared by printing only once on it. Different dopants with certain concentrations could be added into the films by printing with different dopant inks and printing frequency. All Pd, Ag, and ZrO 2 dopants increased both the resistivity and the sensitivity of the films (180 ppm acetone). This work showed that the ink-jet printing technique was a convenient and low cost method to prepare films with controlled film thickness and dopant concentration

Nanostructured Al–Zn–Mg–Cu–Zr alloy prepared by mechanical alloying followed by hot pressing

International Nuclear Information System (INIS)

Azimi, Amin; Shokuhfar, Ali; Zolriasatein, Ashkan

2014-01-01

Nanostructured Al–7.8 wt% Zn–2.6 wt% Mg–2 wt% Cu–0.1 wt% Zr alloy was mechanically alloyed (MA) from elemental powders and consolidated by hot press technique. The effect of the milling time and hot pressing process on microstructure was investigated by means of X-ray diffraction measurements (XRD) and analytical and scanning electron microscopy (SEM). Furthermore mechanical properties of samples with different MA time as well as pure aluminum were investigated by microhardness and compression tests. The results show that an Al–Zn–Mg–Cu–Zr homogenous supersaturated solid solution with a crystallite size of 27 nm was obtained after 40 h of milling time. Microstructure refinement and morphological changes of powders from flake to spherical shape were observed by increasing milling time. Phase and microstructural characterization of high density bulk nanostructured samples revealed that increasing milling time up to 40 h leads to formation of MgZn 2 precipitation in the alloy matrix. With increasing milling time, density of the samples and crystalline size decrease. Significant enhancement of hardness and compressive strength is observed in the aluminum alloy by increasing milling time up to 40 h which is much higher than pure aluminum. Crystallite size refinement in pure aluminum samples from micro- to nanoscales resulted in 107% and 100% improvement in compressive strength and hardness, respectively. Furthermore the compressive strength and hardness of Al–Zn–Mg–Cu–Zr alloy nanostructured samples increased to 179% and 172%, respectively, compared to nanostructured pure Al, which was produced as reference specimen. 40 h of MA was the optimum case for preparing such an Al alloy and more milling up to 50 h led to deterioration of mechanical properties

Preparation and properties of silk sericin/cellulose cross-linking films

Directory of Open Access Journals (Sweden)

Wang Kunyan

2017-01-01

Full Text Available Silk sericin/cellulose cross-linked films were successfully prepared using glutaraldehyde as cross-linkinger. FTIR was applied to characterize the chemical structure of films. Cross-linked silk sericin film was found the peak intensity of FTIR for cross-linked film decreased markedly compared to pure silk sericin, which indicating cross-linking reaction has been occurred. The increasing value of swelling ratio also indicated the cross-linking has been happened. The cross-linking reaction increased the thermal decomposition temperature.

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.

Power ultrasound irradiation during the alkaline etching process of the 2024 aluminum alloy

Energy Technology Data Exchange (ETDEWEB)

Moutarlier, V.; Viennet, R.; Rolet, J.; Gigandet, M.P.; Hihn, J.Y., E-mail: jean-yves.hihn@univ-fcomte.fr

2015-11-15

Graphical abstract: Result of an etching step in ultrasound presence on intermetallic particles on a 2024 aluminum alloy. - Highlights: • Etching step prior to anodization on 2024 aluminum alloy. • Etching rate measurement and hydroxide film characterization by GDOES and SEM. • Various etching parameters (temperature, presence or absence of ultrasound). • Improvement of corrosion resistance show by electrochemical tests. - Abstract: Prior to any surface treatment on an aluminum alloy, a surface preparation is necessary. This commonly consists in performing an alkaline etching followed by acid deoxidizing. In this work, the use of power ultrasound irradiation during the etching step on the 2024 aluminum alloy was studied. The etching rate was estimated by weight loss, and the alkaline film formed during the etching step was characterized by glow discharge optical emission spectrometry (GDOES) and scanning electron microscope (SEM). The benefit of power ultrasound during the etching step was confirmed by pitting potential measurement in NaCl solution after a post-treatment (anodizing).

Power ultrasound irradiation during the alkaline etching process of the 2024 aluminum alloy

International Nuclear Information System (INIS)

Moutarlier, V.; Viennet, R.; Rolet, J.; Gigandet, M.P.; Hihn, J.Y.

2015-01-01

Graphical abstract: Result of an etching step in ultrasound presence on intermetallic particles on a 2024 aluminum alloy. - Highlights: • Etching step prior to anodization on 2024 aluminum alloy. • Etching rate measurement and hydroxide film characterization by GDOES and SEM. • Various etching parameters (temperature, presence or absence of ultrasound). • Improvement of corrosion resistance show by electrochemical tests. - Abstract: Prior to any surface treatment on an aluminum alloy, a surface preparation is necessary. This commonly consists in performing an alkaline etching followed by acid deoxidizing. In this work, the use of power ultrasound irradiation during the etching step on the 2024 aluminum alloy was studied. The etching rate was estimated by weight loss, and the alkaline film formed during the etching step was characterized by glow discharge optical emission spectrometry (GDOES) and scanning electron microscope (SEM). The benefit of power ultrasound during the etching step was confirmed by pitting potential measurement in NaCl solution after a post-treatment (anodizing).

A methodology for the preparation of nanoporous polyimide films with low dielectric constants

International Nuclear Information System (INIS)

Jiang Lizhong; Liu Jiugui; Wu Dezhen; Li Hangquan; Jin Riguang

2006-01-01

A method to generate nanoporous polyimide films with low dielectric constants was proposed. The preparation consisted of two steps. Firstly, a polyimide/silica hybrid film was prepared via sol-gel process. Secondly, the hybrid film was treated with hydrofluoric acid to remove the dispersed silica particles, leaving pores with diameters between 20 and 120 nm, depending on the size of silica particles. Both hybrid and porous films were subjected to a variety of characterizations including transmission electron microscopy observation, dielectric constant measurement and tensile strength measurement

Influence of annealing temperature on properties of Cu(In,Ga)(Se,S){sub 2} thin films prepared by co-sputtering from quaternary alloy and In{sub 2}S{sub 3} targets

Energy Technology Data Exchange (ETDEWEB)

Lin, Y.C., E-mail: ielinyc@cc.ncue.edu.t [Department of Mechatronics Engineering, National Changhua University of Education, No. 2, Shida Road, Changhua 50074, Taiwan (China); Yen, W.T.; Chen, Y.L.; Wang, L.Q. [Department of Mechatronics Engineering, National Changhua University of Education, No. 2, Shida Road, Changhua 50074, Taiwan (China); Jih, F.W. [Chung-Shan Institute of Science and Technology, No. 15, Shi Qi Zi, Gaoping village, Longtan Township, Taoyuan County, Taiwan (China)

2011-02-15

Pentanary Cu(In,Ga)(Se,S){sub 2} (CIGSS) thin films were deposited on soda-lime glass substrate by co-sputtering quaternary alloy, and In{sub 2}S{sub 3} targets. In this study, we investigated the influence of post-annealing temperature on structural, compositional, electrical, and optical properties of CIGSS films. Our experimental results show that the CIGS quaternary target had chalcopyrite characteristics. All CIGSS films annealed above 733 K exhibited a polycrystalline tetragonal chalcopyrite structure, with (1 1 2) preferred orientation. The carrier concentration and resistivity of the resultant CIGSS layer annealed above 763 K was 4.86x10{sup 16} cm{sup -3} and 32 {Omega} cm, respectively, and the optical band-gap of the CIGSS absorber layer was 1.18 eV. Raman spectral analysis demonstrated the existence of many different phases, including CuInSe{sub 2}, CuGaSe{sub 2}, and CuInS{sub 2}. This may be because the vibration frequencies of In-Se, In-S bonds are similar to the Ga-Se and Ga-S bonds, causing their absorption bands overlap. -- Research Highlights: {yields} We report a chalcopyrite Cu(In,Ga)(Se,S){sub 2} (CIGSS) thin films on soda lime glass substrate by co-sputtering quaternary single-phase chalcopyrite CIGS alloy, and In{sub 2}S{sub 3} targets. {yields} By incorporating sulfur into partly selenized CIGS films, researchers fabricated a chalcopyrite CIGSS layer with double-graded band-gap structure. {yields} The CIGS quaternary target and Raman spectra were analyzed for investigating the CIGSS structure and quality.

Semiconducting properties of oxide and passive films formed on AISI 304 stainless steel and Alloy 600

Directory of Open Access Journals (Sweden)

Ferreira M. G. S.

2002-01-01

Full Text Available The semiconducting properties of passive films formed on AISI 304 stainless steel and Alloy 600 in borate buffer solution were studied by capacitance (Mott-Schottky approach and photocurrent measurements. Oxide films formed on 304 stainless steel in air at 350 ºC have also been studied. The results obtained show that, in all cases the electronic structure of the films is comparable to that of a p-n heterojunction in which the space charges developed at the metal-film and film-electrolyte interfaces have also to be considered. This is in accordance with analytical results showing that the oxide films are in all cases composed of an inner region rich in chromium oxide and an outer region rich in iron oxide.

Preparation of boron-nitrogen films by sputtering

International Nuclear Information System (INIS)

Klose, S.; Winde, B.

1980-01-01

Hard boron-nitrogen films adherent to various substrates can be prepared by sputtering. IR investigations suggest the existence of cubic boron nitride in certain layers. Transmission electron microscope studies have shown a quasi-amorphous structure irregularly incorporating crystallites of zinc blende structure of some nm in diameter

CdS thin films prepared by laser assisted chemical bath deposition

International Nuclear Information System (INIS)

Garcia, L.V.; Mendivil, M.I.; Garcia Guillen, G.; Aguilar Martinez, J.A.; Krishnan, B.; Avellaneda, D.; Castillo, G.A.; Das Roy, T.K.; Shaji, S.

2015-01-01

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

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.

Tribological performance of near equiatomic and Ti-rich NiTi shape memory alloy thin films

International Nuclear Information System (INIS)

Tillmann, Wolfgang; Momeni, Soroush

2015-01-01

Near equiatomic and Ti-rich NiTi shape memory alloy thin films were magnetron sputtered with the same processing parameters and thickness of 3 μm. The microstructure, composition, shape memory behavior, mechanical and tribological properties of the deposited thin films were analyzed by using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), differential scanning calorimetry (DSC), nanoindentation, ball-on-disc, scratch test, and three dimensional (3D) optical microscopy. The obtained results clearly show how the crystallization evolution and precipitation formation of these two sets of thin films can drastically influence their mechanical and tribological performances

Pd-Ni-MWCNT nanocomposite thin films: preparation and structure

Science.gov (United States)

Kozłowski, Mirosław; Czerwosz, ElŻbieta; Sobczak, Kamil

2017-08-01

The properties of nanocomposite palladium-nickel-multi-walled (Pd-Ni-MWCNT) films deposited on aluminum oxide (Al2O3) substrate have been prepared and investigated. These films were obtained by 3 step process consisted of PVD/CVD/PVD methods. The morphology and structure of the obtained films were characterized by Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) techniques at various stages of the film formation. EDX spectrometer was used to measurements of elements segregation in the obtained film. TEM and STEM (Scanning Transmission Electron Microscopy) observations showed MWCNTs decorated with palladium nanoparticles in the film obtained in the last step of film formation (final PVD process). The average size of the palladium nanoparticles observed both on MWCNTs and carbonaceous matrix does not exceed 5 nm. The research was conducted on the use of the obtained films as potential sensors of gases (e.g. H2, NH3, CO2) and bio-sensors or optical sensors.

Preparation, microstructure and degradation performance of biomedical magnesium alloy fine wires

Directory of Open Access Journals (Sweden)

Jing Bai

2014-10-01

Full Text Available With the development of new biodegradable Mg alloy implant devices, the potential applications of biomedical Mg alloy fine wires are realized and explored gradually. In this study, we prepared three kinds of Mg alloy fine wires containing 4 wt% RE(Gd/Y/Nd and 0.4 wt% Zn with the diameter less than 0.4 μm through casting, hot extruding and multi-pass cold drawing combined with intermediated annealing process. Their microstructures, mechanical and degradation properties were investigated. In comparison with the corresponding as-extruded alloy, the final fine wire has significantly refined grain with an average size of 3–4 μm, and meanwhile shows higher yield strength but lower ductility at room temperature. The degradation tests results and surface morphologies observations indicate that Mg–4Gd–0.4Zn and Mg–4Nd–0.4Zn fine wires have similar good corrosion resistance and the uniform corrosion behavior in SBF solution. By contrast, Mg–4Y–0.4Zn fine wire shows a poor corrosion resistance and the pitting corrosion behavior.

Applying RF Magnetron sputtering to prepare ZnO thin films and their characterization

International Nuclear Information System (INIS)

Saad, M.; Kassis, A.

2009-05-01

ZnO thin films were prepared using Rf magnetron sputtering under several preparation conditions (different values of deposition pressure, Rf power, substrate temperature). The optical properties of these films were investigated by measuring their transmission in the spectral range (300-1000 nm), and the electrical properties were investigated by measuring their electrical resistance. Results have been discussed in terms of the modified Thornton model for sputtered thin metal oxide films. Preparation conditions for depositing the highly resistive transparent i-ZnO buffer layer and the highly conducting transparent n-ZnO window layer for solar cells were proposed. (author)

Effect of the thickness of a fluoropolymer film on the radiotically prepared fuel cell membranes

Energy Technology Data Exchange (ETDEWEB)

Ko, Beom Seok; Sohn, Joon Yong; Nho, Young Chang; Shin, Jun Hwa [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of); Kim, Jong Il [Chonbuk National University, Jeonju (Korea, Republic of)

2010-06-15

To observe the effect of the thickness of a fluoropolymer film on the radiotically prepared fuel cell membranes, fuel cell membranes with various thickness were prepared by simultaneous radiation grafting of styrene into polyethylene-co-tetrafluoroethylene (ETFE) with various thicknesses (25, 50 and 100 {mu}m) and subsequent sulfonation. The physico-chemical properties of the prepared membranes such as ion exchange capacity, water uptake, distribution of sulfonic acid group were evaluated in the correlation with the thickness of ETFE film. In additions, proton conductivity and methanol permeability of the prepared membranes were also evaluated. The results revealed that the proton conductivity and methanol permeability of the prepared membranes were largely affected by the thickness of ETFE film utilized as a base film.

Effect of the thickness of a fluoropolymer film on the radiotically prepared fuel cell membranes

International Nuclear Information System (INIS)

Ko, Beom Seok; Sohn, Joon Yong; Nho, Young Chang; Shin, Jun Hwa; Kim, Jong Il

2010-01-01

To observe the effect of the thickness of a fluoropolymer film on the radiotically prepared fuel cell membranes, fuel cell membranes with various thickness were prepared by simultaneous radiation grafting of styrene into polyethylene-co-tetrafluoroethylene (ETFE) with various thicknesses (25, 50 and 100 μm) and subsequent sulfonation. The physico-chemical properties of the prepared membranes such as ion exchange capacity, water uptake, distribution of sulfonic acid group were evaluated in the correlation with the thickness of ETFE film. In additions, proton conductivity and methanol permeability of the prepared membranes were also evaluated. The results revealed that the proton conductivity and methanol permeability of the prepared membranes were largely affected by the thickness of ETFE film utilized as a base film

Microstructure of epitaxial thin films of the ferromagnetic shape memory alloy Ni{sub 2}MnGa

Energy Technology Data Exchange (ETDEWEB)

Eichhorn, Tobias

2011-12-09

This work is concerned with the preparation and detailed characterization of epitaxial thin films of the Heusler compound Ni{sub 2}MnGa. This multiferroic compound is of both technological and scientific interest due to the outstanding magnetic shape memory (MSM) behavior. Huge magnetic-field-induced strains up to 10 % have been observed for single crystals close to a Ni{sub 2}MnGa composition. The effect is based on a redistribution of crystallographic twin variants of tetragonal or orthorhombic symmetry. Under the driving force of the external magnetic field twin boundaries can move through the crystal, which largely affects the macroscopic shape. The unique combination of large reversible strain, high switching frequency and high work output makes the alloy a promising actuator material. Since the MSM effect results from an intrinsic mechanism, MSM devices possess great potential for implementation in microsystems, e.g. microfluidics. So far significant strains, in response to an external magnetic field, have been observed for bulk single crystals and foams solely. In order to take advantage of the effect in applications concepts for miniaturization are needed. The rather direct approach, based on epitaxial thin films, is explored in the course of this work. This involves sample preparation under optimized deposition parameters and fabrication of freestanding single-crystalline films. Different methods to achieve freestanding microstructures such as bridges and cantilevers are presented. The complex crystal structure is extensively studied by means of X-ray diffraction. Thus, the different crystallographic twin variants that are of great importance for the MSM effect are identified. In combination with microscopy the twinning architecture for films of different crystallographic orientation is clarified. Intrinsic blocking effects in samples of (100) orientation are explained on basis of the variant configuration. In contrast, a promising twinning microstructure

Roles of texture of Zr alloys in ZrO{sub 2} film formation and δ-hydride orientation near ZrO{sub 2}/Zr interface

Energy Technology Data Exchange (ETDEWEB)

Qin, W.; Szpunar, J.A., E-mail: weq565@mail.usask.ca, E-mail: jerzy.szpunar@usask.ca [Univ. of Saskatchewan, Dept. of Mechanical Engineering, Saskatoon, SK (Canada); Kozinski, J., E-mail: janusz.kozinski@lassonde.yorku.ca [York Univ., Faculty of Science and Engineering, Toronto, ON (Canada)

2014-07-01

Oxidation and hydrogen embrittlement are related to formation of cracks and failure of Zr alloys used in nuclear reactor applications. An in-depth understanding of the formation of ZrO{sub 2} film and the hydride precipitation and orientation is important for improving the corrosion resistance of zirconium alloys. In this work a theoretical model is developed to analyze the microstructure of ZrO{sub 2} film formed on Zr alloys and the effect of stress that results from ZrO{sub 2} formation on hydride reorientation in the region near oxide/metal interface. Our work shows that the macroscopic stress produced due to Pilling-Bedworth ratio for ZrO{sub 2}/Zr could lead to the hydride re-orientation in the region near ZrO{sub 2}/Zr interface. Whether or not this effect can occur is dependent on the texture of the zirconium alloys. Control of texture of zirconium alloys can affect the microstructure of ZrO{sub 2} film and can be responsible for change of hydride orientation. (author)

Characterisation and corrosion resistance of the electrodeposited hydroxyapatite and bovine serum albumin/hydroxyapatite films on Ti-6Al-4V-1Zr alloy surface

International Nuclear Information System (INIS)

Vasilescu, C.; Drob, P.; Vasilescu, E.; Demetrescu, I.; Ionita, D.; Prodana, M.; Drob, S.I.

2011-01-01

Graphical abstract: Display Omitted Research highlights: → EIS spectra for Ti6Al4V1Zr alloy were fitted with one time constant electric equivalent circuit. → For covered alloy the equivalent circuit contains two time constants. → Resistances of films increased in time revealing the improvement of the alloy protection capacity. → Surface roughness significantly increased by apatite formation, being favourably to cell adhesion. - Abstract: A new titanium base Ti-6Al-4V-1Zr alloy covered with hydroxyapatite or bovine serum albumin/hydroxyapatite was characterized in this paper in order to be used as implant material. Following techniques were used: linear polarization, electrochemical impedance spectroscopy, scanning electronic microscopy, Fourier transform infrared spectroscopy and atomic force microscopy. For HA or BSA/HA covered alloy, the electric equivalent circuit contains two time constants (for the passive film and for coatings). The resistance of the protective films increased in time and BSA/HA coating was slightly rougher than HA coating, this situation being favourably to the cell adhesion.

Characterisation and corrosion resistance of the electrodeposited hydroxyapatite and bovine serum albumin/hydroxyapatite films on Ti-6Al-4V-1Zr alloy surface

Energy Technology Data Exchange (ETDEWEB)

Vasilescu, C.; Drob, P. [Institute of Physical Chemistry ' Ilie Murgulescu' of Romanian Academy, Spl. Independentei 202, P.O. Box 12-194, 060021 Bucharest (Romania); Vasilescu, E., E-mail: ec_vasilescu@yahoo.co [Institute of Physical Chemistry ' Ilie Murgulescu' of Romanian Academy, Spl. Independentei 202, P.O. Box 12-194, 060021 Bucharest (Romania); Demetrescu, I.; Ionita, D.; Prodana, M. [Politehnica University of Bucharest, Faculty of Applied Chemistry and Material Science, Str. Polizu 1-7, 011061 Bucharest (Romania); Drob, S.I. [Institute of Physical Chemistry ' Ilie Murgulescu' of Romanian Academy, Spl. Independentei 202, P.O. Box 12-194, 060021 Bucharest (Romania)

2011-03-15

Graphical abstract: Display Omitted Research highlights: {yields} EIS spectra for Ti6Al4V1Zr alloy were fitted with one time constant electric equivalent circuit. {yields} For covered alloy the equivalent circuit contains two time constants. {yields} Resistances of films increased in time revealing the improvement of the alloy protection capacity. {yields} Surface roughness significantly increased by apatite formation, being favourably to cell adhesion. - Abstract: A new titanium base Ti-6Al-4V-1Zr alloy covered with hydroxyapatite or bovine serum albumin/hydroxyapatite was characterized in this paper in order to be used as implant material. Following techniques were used: linear polarization, electrochemical impedance spectroscopy, scanning electronic microscopy, Fourier transform infrared spectroscopy and atomic force microscopy. For HA or BSA/HA covered alloy, the electric equivalent circuit contains two time constants (for the passive film and for coatings). The resistance of the protective films increased in time and BSA/HA coating was slightly rougher than HA coating, this situation being favourably to the cell adhesion.

XPS study of the passive films formed on nitrogen-implanted austenitic stainless steels

International Nuclear Information System (INIS)

Marcus, P.; Bussell, M.E.

1992-01-01

Austenitic stainless steels (304-type) have been implanted with nitrogen ions in order to investigate the effects of implanted nitrogen on their electrochemical behaviour and on the nature of the passive film formed on the steels in acid (0.5M H 2 SO 4 ). Alloys with two nitrogen doses have been prepared (2.5x10 16 and 2x10 17 N atoms/cm 2 ). The implanted alloys have been characterized by 15 N-NRA (nuclear reaction analysis) and XPS (X-ray photoelectron spectroscopy). Alloy surfaces with well-defined N concentrations were prepared, prior to the electrochemical measurements, by argon-ion sputtering of the implanted material for a fixed time in order to reach a well-defined point on the nitrogen depth profile. The samples were then transferred without exposure to air to an electrochemical cell mounted in an inert gas glove box. The implanted nitrogen modifies the electrochemical behaviour of the alloy. The anodic dissolution in the active state is enhanced, and the current density in the passive state is increased. Surface analysis of the alloys by XPS after passivation shows that implanted nitrogen is enriched on the surface during dissolution and passivation of the alloys. The process by which N is enriched on the surface is anodic segregation, which was first observed and characterized for S on Ni and Ni-Fe alloys. The passive films formed on both the unimplanted and implanted alloys have a bilayer structure with an inner oxide layer and an outer hydroxide layer, but on the nitrogen-implanted alloy, a chromium nitride phase is formed at the expense of the chromium oxide. After passivation of the implanted alloys, three chemical states of nitrogen are detected in the N 1s spectrum. The high binding energy (399.4 eV) peak corresponds to a nitrogen species located on the surface of the passive film, which is produced by reaction of the implanted nitrogen with the solution. (orig./WL)

Preparation of Surlyn films reinforced with cellulose nanofibres and feasibility of applying the transparent composite films for organic photovoltaic encapsulation

Science.gov (United States)

Lertngim, Anantaya; Phiriyawirut, Manisara; Wootthikanokkhan, Jatuphorn; Yuwawech, Kitti; Sangkhun, Weradesh; Kumnorkaew, Pisist; Muangnapoh, Tanyakorn

2017-10-01

This research concerns the development of Surlyn film reinforced with micro-/nanofibrillated celluloses (MFC) for use as an encapsulant in organic photovoltaic (OPV) cells. The aim of this work was to investigate the effects of fibre types and the mixing methods on the structure-properties of the composite films. Three types of cellulose micro/nanofibrils were prepared: the as-received MFC, the dispersed MFC and the esterified MFC. The fibres were mixed with Surlyn via an extrusion process, using two different mixing methods. It was found that the extent of fibre disintegration and tensile modulus of the composite films prepared by the master-batching process was superior to that of the composite system prepared by the direct mixing method. Using the esterified MFC as a reinforcement, compatibility between polymer and the fibre increased, accompanied with the improvement of the percentage elongation of the Surlyn composite film. The percentage of light transmittance of the Surlyn/MFC films was above 88, regardless of the fibre types and fibre concentrations. The water vapour transmission rate of the Surlyn/esterified MFC film was 65% lower than that of the neat Surlyn film. This contributed to the longer lifetime of the OPV encapsulated with the Surlyn/esterified MFC film.

High-Strength Ultra-Fine-Grained Hypereutectic Al-Si-Fe-X (X = Cr, Mn) Alloys Prepared by Short-Term Mechanical Alloying and Spark Plasma Sintering.

Science.gov (United States)

Průša, Filip; Bláhová, Markéta; Vojtěch, Dalibor; Kučera, Vojtěch; Bernatiková, Adriana; Kubatík, Tomáš František; Michalcová, Alena

2016-11-30

In this work, Al-20Si-10Fe-6Cr and Al-20Si-10Fe-6Mn (wt %) alloys were prepared by a combination of short-term mechanical alloying and spark plasma sintering. The microstructure was composed of homogeneously dispersed intermetallic particles forming composite-like structures. X-ray diffraction analysis and TEM + EDS analysis determined that the α-Al along with α-Al 15 (Fe,Cr)₃Si₂ or α-Al 15 (Fe,Mn)₃Si₂ phases were present, with dimensions below 130 nm. The highest hardness of 380 ± 7 HV5 was observed for the Al-20Si-10Fe-6Mn alloy, exceeding the hardness of the reference as-cast Al-12Si-1Cu-1 Mg-1Ni alloy (121 ± 2 HV5) by nearly a factor of three. Both of the prepared alloys showed exceptional thermal stability with the hardness remaining almost the same even after 100 h of annealing at 400 °C. Additionally, the compressive strengths of the Al-20Si-10Fe-6Cr and Al-20Si-10Fe-6Mn alloys reached 869 MPa and 887 MPa, respectively, and had virtually the same values of 870 MPa and 865 MPa, respectively, even after 100 h of annealing. More importantly, the alloys showed an increase in ductility at 400 °C, reaching several tens of percent. Thus, both of the investigated alloys showed better mechanical properties, including superior hardness, compressive strength and thermal stability, as compared to the reference Al-10Si-1Cu-1Mg-1Ni alloy, which softened remarkably, reducing its hardness by almost 50% to 63 ± 8 HV5.

High-Strength Ultra-Fine-Grained Hypereutectic Al-Si-Fe-X (X = Cr, Mn) Alloys Prepared by Short-Term Mechanical Alloying and Spark Plasma Sintering

Science.gov (United States)

Průša, Filip; Bláhová, Markéta; Vojtěch, Dalibor; Kučera, Vojtěch; Bernatiková, Adriana; Kubatík, Tomáš František; Michalcová, Alena

2016-01-01

In this work, Al-20Si-10Fe-6Cr and Al-20Si-10Fe-6Mn (wt %) alloys were prepared by a combination of short-term mechanical alloying and spark plasma sintering. The microstructure was composed of homogeneously dispersed intermetallic particles forming composite-like structures. X-ray diffraction analysis and TEM + EDS analysis determined that the α-Al along with α-Al15(Fe,Cr)3Si2 or α-Al15(Fe,Mn)3Si2 phases were present, with dimensions below 130 nm. The highest hardness of 380 ± 7 HV5 was observed for the Al-20Si-10Fe-6Mn alloy, exceeding the hardness of the reference as-cast Al-12Si-1Cu-1 Mg-1Ni alloy (121 ± 2 HV5) by nearly a factor of three. Both of the prepared alloys showed exceptional thermal stability with the hardness remaining almost the same even after 100 h of annealing at 400 °C. Additionally, the compressive strengths of the Al-20Si-10Fe-6Cr and Al-20Si-10Fe-6Mn alloys reached 869 MPa and 887 MPa, respectively, and had virtually the same values of 870 MPa and 865 MPa, respectively, even after 100 h of annealing. More importantly, the alloys showed an increase in ductility at 400 °C, reaching several tens of percent. Thus, both of the investigated alloys showed better mechanical properties, including superior hardness, compressive strength and thermal stability, as compared to the reference Al-10Si-1Cu-1Mg-1Ni alloy, which softened remarkably, reducing its hardness by almost 50% to 63 ± 8 HV5. PMID:28774094

Influence of molybdate species on the tartaric acid/sulphuric acid anodic films grown on AA2024 T3 aerospace alloy

Energy Technology Data Exchange (ETDEWEB)

Garcia-Rubio, M. [Departamento de Quimica-Fisica Aplicada, Universidad Autonoma de Madrid, 28049 Madrid (Spain); Department of Surface Technologies, Engineering of Materials and Processes, Airbus Spain, Av. John Lennon s/n 28906 Getafe (Spain); Ocon, P. [Departamento de Quimica-Fisica Aplicada, Universidad Autonoma de Madrid, 28049 Madrid (Spain)], E-mail: pilar.ocon@uam.es; Climent-Font, A. [Departamento de Fisica Aplicada, Universidad Autonoma de Madrid (UAM), 28049 Madrid (Spain); Centro de Micro-Analisis de Materiales (CMAM), Universidad Autonoma de Madrid (UAM), 28049 Madrid (Spain); Smith, R.W. [Unidad de Microanalisis de Materiales, Parque Cientifico de Madrid (PCM), Campus de Cantoblanco, 28049 Madrid (Spain); Curioni, M.; Thompson, G.E.; Skeldon, P. [Corrosion and Protection Centre, School of Materials, University of Manchester, M60 1QD England (United Kingdom); Lavia, A.; Garcia, I. [Department of Surface Technologies, Engineering of Materials and Processes, Airbus Spain, Av. John Lennon s/n 28906 Getafe (Spain)

2009-09-15

AA2024 T3 alloy specimens have been anodised in tartaric acid/sulphuric media and tartaric acid/sulphuric media containing sodium molybdate; molybdate species were added to the anodising bath to enhance further the protection provided by the porous anodic film developed over the macroscopic alloy surface. Morphological characterisation of the anodic films formed in both electrolytes was undertaken using scanning electron and transmission electron microscopies; the chemical compositions of the films were determined by Rutherford backscattering spectroscopy that was complemented by elemental depth profiling using rf-glow discharge optical emission spectrometry. The electrochemical behaviour was evaluated using potentiodynamic polarisations and electrochemical impedance spectroscopy; the corrosion performance was examined after salt spray testing. The porous anodic film morphology was little influenced by the addition of molybdate salt, although thinner films were generated in its presence. Chemical composition of the anodic film was roughly similar; however, addition of sodium molybdate in the anodizing bath resulted in residues of molybdate species in the porous skeleton and improved corrosion resistance measured by electrochemical techniques that was confirmed by salt spray testing.

Influence of molybdate species on the tartaric acid/sulphuric acid anodic films grown on AA2024 T3 aerospace alloy

International Nuclear Information System (INIS)

Garcia-Rubio, M.; Ocon, P.; Climent-Font, A.; Smith, R.W.; Curioni, M.; Thompson, G.E.; Skeldon, P.; Lavia, A.; Garcia, I.

2009-01-01

AA2024 T3 alloy specimens have been anodised in tartaric acid/sulphuric media and tartaric acid/sulphuric media containing sodium molybdate; molybdate species were added to the anodising bath to enhance further the protection provided by the porous anodic film developed over the macroscopic alloy surface. Morphological characterisation of the anodic films formed in both electrolytes was undertaken using scanning electron and transmission electron microscopies; the chemical compositions of the films were determined by Rutherford backscattering spectroscopy that was complemented by elemental depth profiling using rf-glow discharge optical emission spectrometry. The electrochemical behaviour was evaluated using potentiodynamic polarisations and electrochemical impedance spectroscopy; the corrosion performance was examined after salt spray testing. The porous anodic film morphology was little influenced by the addition of molybdate salt, although thinner films were generated in its presence. Chemical composition of the anodic film was roughly similar; however, addition of sodium molybdate in the anodizing bath resulted in residues of molybdate species in the porous skeleton and improved corrosion resistance measured by electrochemical techniques that was confirmed by salt spray testing.

Properties of pentacene-based films prepared using a heated tungsten mesh

Energy Technology Data Exchange (ETDEWEB)

Heya, Akira, E-mail: heya@eng.u-hyogo.ac.jp; Matsuo, Naoto

2014-11-03

A heated tungsten (W) mesh, set between a pentacene source and a substrate in a vacuum chamber, was used to prepare a bulk-phase pentacene film and a pentacene-based organic semiconductor film. Since the pentacene molecules come into contact with the heated W mesh before reaching the substrate, their thermal energy is increased prior to deposition. As the mesh temperature was increased from 23 to 1200 °C, the intensity ratio of bulk to thin-film phases increased from 0 to 9.7. Above 1300 °C there is a notable decomposition reaction, the products of which were identified as dihydropentacene, p-distrylbenzene, and 2,2′-dimethyl-1,1′-binaphthalene. These decomposed precursors are expected to provide a potential source of large graphene sheets and graphene nanoribbons. - Highlights: • Organic semiconductor films were prepared using pentacene, H{sub 2} gas, and heated W mesh. • The effect of mesh temperature on film deposition was observed. • Pentacene decomposition above 1300 °C provides graphene precursors. • A method is proposed for controlling the sheet resistance of organic films.

Determination of the area density and composition of alloy film using dual alpha particle energy loss