Shape memory characteristics of sputter-deposited Ti-Ni thin films

International Nuclear Information System (INIS)

Miyazaki, Shuichi; Ishida, Akira.

1994-01-01

Ti-Ni shape memory alloy thin films were deposited using an RF magnetron sputtering apparatus. The as-sputtered films were heat-treated in order to crystallize and memorize. After the heat treatment, the shape memory characteristics have been investigated using DSC and thermomechanical tests. Upon cooling the thin films, the solution-treated films showed a single peak in the DSC curve indicating a single stage transformation occurring from B2 to the martensitic phase, while the age-treated films showed double peaks indicating a two-stage transformation, i.e., from B2 to the R-phase, then to the martensitic phase. A perfect shape memory effect was achieved in these sputter-deposited Ti-Ni thin films in association both with the R-phase and martensitic transformations. Transformation temperatures increased linearly with increasing applied stress. The transformation strain also increased with increasing stress. The shape memory characteristics were strongly affected by heat-treatment conditions. (author)

Measurement of partial coefficients of sputtering of titanium atoms from TiC and TiN coatings

International Nuclear Information System (INIS)

Vychegzhanin, G.A.; Gribanov, Yu.A.; Dikij, N.P.; Zhmurin, P.N.; Letuchij, A.N.; Matyash, P.P.; Sidokur, P.I.; Shono, D.A.

1989-01-01

Method of laser fluorescent spectroscopy was used to measure partial coefficients of sputtering of titanium atoms from TiC and TiN coatings under irradiation by 1 keV hydrogen ions. Irradiation was conducted in a plant with reflective discharge. Investigation of damaged layer in irradiated samples was conducted. The presence of near-the-surface layer enrichment with titanium atoms was revealed both in TiC and TiN samples. 12 refs.; 4 figs

Controlled formation of anatase and rutile TiO₂ thin films by reactive magnetron sputtering

OpenAIRE

Rafieian, Damon; Ogieglo, Wojciech; Savenije, T.J.; Lammertink, Rob G H

2015-01-01

We discuss the formation of TiO2 thin films via DC reactive magnetron sputtering. The oxygen concentration during sputtering proved to be a crucial parameter with respect to the final film structure and properties. The initial deposition provided amorphous films that crystallise upon annealing to anatase or rutile, depending on the initial sputtering conditions. Substoichiometric films (TiOx), obtained by sputtering at relatively low oxygen concentration, formed rutile upon annealing in air, ...

Room temperature growth of nanocrystalline anatase TiO2 thin films by dc magnetron sputtering

International Nuclear Information System (INIS)

Singh, Preetam; Kaur, Davinder

2010-01-01

We report, the structural and optical properties of nanocrystalline anatase TiO 2 thin films grown on glass substrate by dc magnetron sputtering at room temperature. The influence of sputtering power and pressure over crystallinity and surface morphology of the films were investigated. It was observed that increase in sputtering power activates the TiO 2 film growth from relative lower surface free energy to higher surface free energy. XRD pattern revealed the change in preferred orientation from (1 0 1) to (0 0 4) with increase in sputtering power, which is accounted for different surface energy associated with different planes. Microstructure of the films also changes from cauliflower type to columnar type structures with increase in sputtering power. FESEM images of films grown at low pressure and low sputtering power showed typical cauliflower like structure. The optical measurement revealed the systematic variation of the optical constants with deposition parameters. The films are highly transparent with transmission higher than 90% with sharp ultraviolet cut off. The transmittance of these films was found to be influenced by the surface roughness and film thickness. The optical band gap was found to decrease with increase in the sputtering power and pressure. The refractive index of the films was found to vary in the range of 2.50-2.24 with increase in sputtering pressure or sputtering power, resulting in the possibility of producing TiO 2 films for device applications with different refractive index, by changing the deposition parameters.

Sputtered PdO Decorated TiO2 Sensing Layer for a Hydrogen Gas Sensor

Directory of Open Access Journals (Sweden)

Jeong Hoon Lee

2018-01-01

Full Text Available We report a sputtered PdO decorated TiO2 sensing layer by radiofrequency (RF sputtering methods and demonstrated gas sensing performance for H2 gas. We prepared sputtered anatase TiO2 sensing films with 200 nm thickness and deposited a Pd layer on top of the TiO2 films with a thickness ranging from 3 nm to 13 nm. Using an in situ TiO2/Pd multilayer annealing process at 550°C for 1 hour, we observed that Pd turns into PdO by Auger electron spectroscopy (AES depth profile and confirmed decorated PdO on TiO2 sensing layer from scanning electron microscope (SEM and atomic-force microscope (AFM. We also observed a positive sensing signal for 3, 4.5, and 6.5 nm PdO decorated TiO2 sensor while we observed negative output signal for a 13.5 nm PdO decorated one. Using a microheater platform, we acquired fast response time as ~11 sec and sensitivity as 6 μV/ppm for 3 nm PdO under 33 mW power.

Mechanical and structural properties of sputtered Ni/Ti multilayers

Energy Technology Data Exchange (ETDEWEB)

Senthil Kumar, M.; Boeni, P.; Tixier, S.; Clemens, D.; Horisberger, M. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1997-09-01

Ni/Ti bilayers have been prepared by dc-magnetron sputtering in order to study their mechanical and structural properties. A remarkable reduction of stress is observed when the Ni layers are sputtered reactively in argon with a high partial pressure of air. The high angle x-ray diffraction studies show a tendency towards amorphisation of the Ni layers with increasing air flow. The low angle measurements indicate a substantial reduction of interdiffusion resulting in smoother interfaces with increasing air content. (author) 2 figs., 2 refs.

Thin films preparation of the Ti-Al-O system by rf-sputtering

International Nuclear Information System (INIS)

Montes de Oca, J. A.; Ceballos A, J.; Galaviz P, J.; Manaud, J. P.; Lahaye, M.; Munoz S, J.

2010-01-01

In the present work Ti-Al-O thin films were synthesized by rf-sputtering technique on glass and silicon (Si) substrates using Ti Al and Ti 3 Al targets in a sputtering chamber with an Ar-O 2 atmosphere. Ti-Al-O thin films were obtained varying experimental parameters such as oxygen percent fed to the reaction chamber, plasma power density and substrate temperature. The films deposited on glass substrates were used to evaluate their optical properties, while those deposited on Si substrates were used to evaluate mechanical and morphological properties. The crystalline structure, morphology, chemical composition and optical properties of the films were evaluated by X-ray diffraction, high-resolution scanning electron microscopy, Auger electron microscopy and visible UV spectroscopy. Films thicknesses were measured using a profiler. The roughness and mechanical properties such as hardness and Young modulus were analyzed by atomic force microscopy and nano indentation technique, respectively. (Author)

Initial growth and texture formation during reactive magnetron sputtering of TiN on Si(111)

CERN Document Server

Li, T Q; Tsuji, Y; Ohsawa, T; Komiyama, H

2002-01-01

The initial growth and texture formation mechanism of titanium nitride (TiN) films were investigated by depositing TiN films on (111) silicon substrates by using reactive magnetron sputtering of a Ti metallic target under a N sub 2 /Ar atmosphere, and then analyzing the films in detail by using transmission electron microscopy (TEM) and x-ray diffraction (XRD). Two power sources for the sputtering, dc and rf, were compared. At the initial growth stage, a continuous amorphous film containing randomly oriented nuclei was observed when the film thickness was about 3 nm. The nuclei grew and formed a polycrystalline layer when the film thickness was about 6 nm. As the film grew further, its orientation changed depending on the deposition conditions. For dc sputtering, the appearance of (111) or (200)-preferred orientations depended on the N sub 2 partial pressure, and the intensity of the preferred orientation increased with increasing film thickness. For rf sputtering, however, when the film thickness was small (...

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

Ion beam sputtering of Ti: Influence of process parameters on angular and energy distribution of sputtered and backscattered particles

Energy Technology Data Exchange (ETDEWEB)

Lautenschläger, T. [Leibniz-Institute of Surface Modification, 04318 Leipzig (Germany); Feder, R., E-mail: thomas.lautenschlaeger@iom-leipzig.de [Leibniz-Institute of Surface Modification, 04318 Leipzig (Germany); Neumann, H. [Leibniz-Institute of Surface Modification, 04318 Leipzig (Germany); Rice, C.; Schubert, M. [Department of Electrical and Computer Engineering and Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, Nebraska 68588-0511 (United States); Bundesmann, C. [Leibniz-Institute of Surface Modification, 04318 Leipzig (Germany)

2016-10-15

Highlights: • Ion beam sputter deposition under systematic variation of process parameters. • Angular and energy distribution of secondary particles. • Interaction between incorporated and impinging process gas. • Measured data compared with simulations. - Abstract: In the present study, the influence of ion energy and geometrical parameters onto the angular and energy distribution of secondary particles for sputtering a Ti target with Ar ions is investigated. The angular distribution of the particle flux of the sputtered Ti atoms was determined by the collection method, i.e. by growing Ti films and measuring their thickness. The formal description of the particle flux can be realized by dividing it into an isotropic and an anisotropic part. The experimental data show that increasing the ion energy or decreasing the ion incidence angle lead to an increase of the isotropic part, which is in good agreement with basic sputtering theory. The energy distribution of the secondary ions was measured using an energy-selective mass spectrometer. The energy distribution of the sputtered target ions shows a maximum at an energy between 10 eV and 20 eV followed by a decay proportional to E{sup −n}, which is in principle in accordance with Thompson’s theory, followed by a high energetic tail. When the sum of incidence angle and emission angle is increased, the high-energetic tail expands to higher energies and an additional peak due to direct sputtering events may occur. In the case of backscattered primary Ar ions, a maximum at an energy between 5 eV and 10 eV appears and, depending on the scattering geometry, an additional broad peak at a higher energy due to direct scattering events is observed. The center energy of the additional structure shifts systematically to higher energies with decreasing scattering angle or increasing ion energy. The experimental results are compared to calculations based on simple elastic two-particle-interaction theory and to

Advanced TiC/a-C : H nanocomposite coatings deposited by magnetron sputtering

NARCIS (Netherlands)

Pei, Y.T.; Galvan, D.; Hosson, J.Th.M. De; Strondl, C.

2006-01-01

TiC/a-C:H nanocomposite coatings have been deposited by magnetron Sputtering. They consist of 2-5 nm TiC nanocrystallites embedded in the amorphous hydrocarbon (a-C:H) matrix. A transition from a Columnar to a glassy microstructure has been observed in the nanocomposite coatings with increasing

Room temperature growth of nanocrystalline anatase TiO{sub 2} thin films by dc magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Singh, Preetam, E-mail: preetamphy@gmail.co [Functional Nanomaterials Research Lab, Department of Physics and Centre of Nanotechnology, Indian Institute of Technology Roorkee, Roorkee 247667 (India); Kaur, Davinder [Functional Nanomaterials Research Lab, Department of Physics and Centre of Nanotechnology, Indian Institute of Technology Roorkee, Roorkee 247667 (India)

2010-03-01

We report, the structural and optical properties of nanocrystalline anatase TiO{sub 2} thin films grown on glass substrate by dc magnetron sputtering at room temperature. The influence of sputtering power and pressure over crystallinity and surface morphology of the films were investigated. It was observed that increase in sputtering power activates the TiO{sub 2} film growth from relative lower surface free energy to higher surface free energy. XRD pattern revealed the change in preferred orientation from (1 0 1) to (0 0 4) with increase in sputtering power, which is accounted for different surface energy associated with different planes. Microstructure of the films also changes from cauliflower type to columnar type structures with increase in sputtering power. FESEM images of films grown at low pressure and low sputtering power showed typical cauliflower like structure. The optical measurement revealed the systematic variation of the optical constants with deposition parameters. The films are highly transparent with transmission higher than 90% with sharp ultraviolet cut off. The transmittance of these films was found to be influenced by the surface roughness and film thickness. The optical band gap was found to decrease with increase in the sputtering power and pressure. The refractive index of the films was found to vary in the range of 2.50-2.24 with increase in sputtering pressure or sputtering power, resulting in the possibility of producing TiO{sub 2} films for device applications with different refractive index, by changing the deposition parameters.

Electrochromism and photocatalysis in dendrite structured Ti:WO3 thin films grown by sputtering

Energy Technology Data Exchange (ETDEWEB)

Karuppasamy, A., E-mail: karuppasamy@psnacet.edu.in

2015-12-30

Graphical abstract: - Highlights: • Dendrite structured Ti doped WO{sub 3} (WTO) thin films are grown by co-sputtering. • Sputtering condition influences structure and surface morphology of WTO films. • Titanium doping and annealing lead to dendritic surface structures in WTO films. • Structural, optical, electrochromic and photocatalytic properties of WTO films. • Enhanced electrochromism and photocatalysis in dendrite structured WTO thin films. - Abstract: Titanium doped tungsten oxide (Ti:WO{sub 3}) thin films with dendrite surface structures were grown by co-sputtering titanium and tungsten in Ar + O{sub 2} atmosphere. Ti:WO{sub 3} thin films were deposited at oxygen flow rates corresponding to pressures in the range 1.0 × 10{sup −3}–5.0 × 10{sup −3} mbar. Argon flow rate and sputtering power densities for titanium (2 W/cm{sup 2}) and tungsten (3 W/cm{sup 2}) were kept constant. Ti:WO{sub 3} films deposited at an oxygen pressure of 5 × 10{sup −3} mbar are found to be better electrochromic and photocatalytic. They have high optical modulation (80% at λ = 550 nm), coloration efficiency (60 cm{sup 2}/C at λ = 550 nm), electron/ion storage and removal capacity (Qc: −22.01 mC/cm{sup 2}, Qa: 17.72 mC/cm{sup 2}), reversibility (80%) and methylene blue decomposition rate (−1.38 μmol/l d). The combined effects of titanium doping, dendrite surface structures and porosity leads to significant enhancement in the electrochromic and photocatalytic properties of Ti:WO{sub 3} films.

Electrochromism and photocatalysis in dendrite structured Ti:WO3 thin films grown by sputtering

International Nuclear Information System (INIS)

Karuppasamy, A.

2015-01-01

Graphical abstract: - Highlights: • Dendrite structured Ti doped WO 3 (WTO) thin films are grown by co-sputtering. • Sputtering condition influences structure and surface morphology of WTO films. • Titanium doping and annealing lead to dendritic surface structures in WTO films. • Structural, optical, electrochromic and photocatalytic properties of WTO films. • Enhanced electrochromism and photocatalysis in dendrite structured WTO thin films. - Abstract: Titanium doped tungsten oxide (Ti:WO 3 ) thin films with dendrite surface structures were grown by co-sputtering titanium and tungsten in Ar + O 2 atmosphere. Ti:WO 3 thin films were deposited at oxygen flow rates corresponding to pressures in the range 1.0 × 10 −3 –5.0 × 10 −3 mbar. Argon flow rate and sputtering power densities for titanium (2 W/cm 2 ) and tungsten (3 W/cm 2 ) were kept constant. Ti:WO 3 films deposited at an oxygen pressure of 5 × 10 −3 mbar are found to be better electrochromic and photocatalytic. They have high optical modulation (80% at λ = 550 nm), coloration efficiency (60 cm 2 /C at λ = 550 nm), electron/ion storage and removal capacity (Qc: −22.01 mC/cm 2 , Qa: 17.72 mC/cm 2 ), reversibility (80%) and methylene blue decomposition rate (−1.38 μmol/l d). The combined effects of titanium doping, dendrite surface structures and porosity leads to significant enhancement in the electrochromic and photocatalytic properties of Ti:WO 3 films.

In situ crystallization of sputter-deposited TiNi by ion irradiation

International Nuclear Information System (INIS)

Ikenaga, Noriaki; Kishi, Yoichi; Yajima, Zenjiro; Sakudo, Noriyuki

2013-01-01

Highlights: ► We developed a sputtering deposition process equipped with an ion irradiation system. ► Ion irradiation enables crystallization at lower substrate temperature. ► Ion fluence has an effective range for low-temperature crystallization. ► Crystallized films made on polyimide by the process show the shape memory effect. -- Abstract: TiNi is well known as a typical shape-memory alloy, and the shape-memory property appears only when the structure is crystalline. Until recently, the material has been formed as amorphous film by single-target sputtering deposition at first and then crystallized by being annealed at high temperature over 500 °C. Therefore, it has been difficult to make crystalline TiNi film directly on a substrate of polymer-based material because of the low heat resistance of substrate. In order to realize an actuator from the crystallized TiNi film on polymer substrates, the substrate temperature should be kept below 200 °C throughout the whole process. In our previous studies we have found that deposited film can be crystallized at very low temperature without annealing but with simultaneous irradiation of Ar ions during sputter-deposition. And we have also demonstrated the shape-memory effect with the TiNi film made by the new process. In order to investigate what parameters of the process contribute to the low-temperature crystallization, we have focused to the ion fluence of the ion irradiation. Resultantly, it was found that the transition from amorphous structure to crystal one has a threshold range of ion fluence

Characterization of TiO2 Thin Films on Glass Substrate Growth Using DC Sputtering Technique

International Nuclear Information System (INIS)

Agus Santoso; Tjipto Sujitno; Sayono

2002-01-01

It has been fabricated and characterization a TiO 2 thin films deposited on glass substrate using DC sputtering technique. Fabrication of TiO 2 thin films were carried out at electrode voltage 4 kV, sputtering current 5 mA, vacuum pressure 5 x 10 -4 torr, deposition time 150 minutes, and temperature of the substrate were varied from 150 -350 o C, while as a gas sputter was argon. The results was tested their micro structure using SEM, and crystal structure using XRD and found that the crystal structure of TiO 2 powder before deposited on glass substrate was rutile and anatase with orientation (110) and (200) for anatase and (100) and (111) rutile structure. While the crystal structure which deposited at temperature 150 o C and deposition time 2.5 hours was anatase with orientation (001) and (200). (author)

Visible light active Au:TiO2 nanocomposite photoanodes for water splitting: Sol-gel vs. sputtering

International Nuclear Information System (INIS)

Naseri, N.; Sangpour, P.; Moshfegh, A.Z.

2011-01-01

In this study, pure TiO 2 and Au:TiO 2 nanocomposite thin films are both synthesized using sol-gel and RF reactive co-sputtering methods. Physical and photoelectrochemical properties of the thin films deposited by each method are compared. The optical density spectra and scanning electron microscopy images of the Au:TiO 2 films reveal formation of gold nanoparticles in the all nanocomposite films synthesized by two methods. Moreover, the optical bandgap energy of the thin films decreases with addition of Au nanoparticles. X-ray photoelectron spectroscopy indicates that the presence of gold in metallic state and the formation of TiO 2 is stoichiometric. The photoelectrochemical properties of the TiO 2 and Au:TiO 2 thin films are characterized by using a compartment cell containing KOH solution as electrolyte. It is found that in the pure systems, TiO 2 sputtered films shows a higher photocurrent under visible light illumination while a reverse result is obtained for the Au:TiO 2 systems. In addition, photoirradiation on electrode/electrolyte (EE) and substrate/electrode (SE) interfaces for the sputtered samples reveals the EE illumination enhances the photoresponse of the layers as compared to SE case.

Enhancement of Ti-containing hydrogenated carbon (Ti-C:H) films by high-power plasma-sputtering

International Nuclear Information System (INIS)

Gwo, Jyh; Chu, Chun-Lin; Tsai, Ming-Jui; Lee, Shyong

2012-01-01

Ti-containing amorphous hydrogenated carbon (Ti-C:H) thin films were deposited on stainless steel SS304 substrates by high-power pulsed magnetron sputtering (HPPMS) in an atmosphere of mixed Ar and C 2 H 2 gases using titanium metal as the cathodic material. The multilayer structure of the deposited film had a Ti-TiC-DLC gradient to improve adhesion and reduce residual stress. This study investigates the effects of substrate bias and target-to-substrate distance on the mechanical properties of Ti-C:H films. Film properties, including composition, morphology, microstructure, mechanical, and tribology, were examined by glow discharge spectroscopy (GDS), scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, and a nanoindenter and a pin-on-disk tribometer. Experiments revealed impressive results.

Rutile TiO2 thin films grown by reactive high power impulse magnetron sputtering

International Nuclear Information System (INIS)

Agnarsson, B.; Magnus, F.; Tryggvason, T.K.; Ingason, A.S.; Leosson, K.; Olafsson, S.; Gudmundsson, J.T.

2013-01-01

Thin TiO 2 films were grown on Si(001) substrates by reactive dc magnetron sputtering (dcMS) and high power impulse magnetron sputtering (HiPIMS) at temperatures ranging from 300 to 700 °C. Optical and structural properties of films were compared both before and after post-annealing using scanning electron microscopy, low angle X-ray reflection (XRR), grazing incidence X-ray diffractometry and spectroscopic ellipsometry. Both dcMS- and HiPIMS-grown films reveal polycrystalline rutile TiO 2 , even prior to post-annealing. The HiPIMS-grown films exhibit significantly larger grains compared to that of dcMC-grown films, approaching 100% of the film thickness for films grown at 700 °C. In addition, the XRR surface roughness of HiPIMS-grown films was significantly lower than that of dcMS-grown films over the whole temperature range 300–700 °C. Dispersion curves could only be obtained for the HiPIMS-grown films, which were shown to have a refractive index in the range of 2.7–2.85 at 500 nm. The results show that thin, rutile TiO 2 films, with high refractive index, can be obtained by HiPIMS at relatively low growth temperatures, without post-annealing. Furthermore, these films are smoother and show better optical characteristics than their dcMS-grown counterparts. - Highlights: • We demonstrate growth of rutile TiO 2 on Si (111) by high power impulse magnetron sputtering. • The films exhibit significantly larger grains than dc magnetron sputtered films • TiO 2 films with high refractive index are obtained without post-growth annealing

Mechanical properties of TiN films deposited by changed-pressure r.f. sputtering

International Nuclear Information System (INIS)

Kubo, Y.; Hashimoto, M.

1991-01-01

TiN was deposited onto glass, stainless steel and cemented carbide by r.f. magnetron sputtering. The mechanical properties of TiN such as hardness, internal stress and adhesion were assessed by the Vickers microhardness test, the bending method and the modified scratch test. It was found that the operating pressure during sputtering deposition strongly affects these mechanical properties. As the operating pressure is increased beyond 0.6-0.7 Pa, the adhesion of TiN films onto the substrate increases enormously, but the hardness decreases owing to the release of the high compressive stress in the film. Therefore changing the pressure from high to low during deposition could be a good way of optimizing both hardness and adhesion. The effectiveness of this changed-pressure process was experimentally verified by cutting tests using TiN-coated cemented carbide tools. This process will be applicable to any other hard coating materials having high compressive stresses. (orig.)

Magnetron reactively sputtered Ti-DLC coatings on HNBR rubber : The influence of substrate bias

NARCIS (Netherlands)

Bui, X.L.; Pei, Y.T.; Hosson, J.Th.M. De

2008-01-01

In this study, Ti-containing diamond-like carbon (Ti-DLC) coatings have been deposited on HNBR (hydrogenated nitrile butadiene) rubber and also on Si wafer as reference via unbalanced magnetroli reactive sputtering from a Ti target in C2H2/Ar plasma. The deposition rates of coatings on rubber and Si

Biomineralisation with Saos-2 bone cells on TiSiN sputtered Ti alloys.

Science.gov (United States)

V V, Anusha Thampi; Bendavid, Avi; Martin, P J; Vaithilingam, Vijay; Bean, Penelope A; Evans, Margaret D M; Subramanian, B

2017-07-01

Surface modifications of metallic implants are important in order to protect the underlying metals from the harsh corrosive environment inside the human body and to minimize the losses caused by wear. Recently, researches are carried out in developing bioactive surfaces on metallic implants, which supports the growth and proliferation of cells on to these surfaces. Titanium silicon nitride (TiSiN) hard nanocomposites thin films were fabricated on Ti alloys (Ti-6Al-4V) by pulsed direct current (DC) reactive magnetron sputtering. The films were characterized for its microstructural and electrochemical behavior. The higher charge transfer resistance (Rct) and positive shift in Ecorr value of TiSiN/Ti alloys than the bare Ti-alloys indicates a better corrosion resistance offered by the TiSiN thin films to the underlying substrates. The biological response to TiSiN/Ti alloys and control bare Ti-alloys was measured in vitro using cell-based assays with two main outcomes. Firstly, neither the Ti alloy nor the TiSiN thin film was cytotoxic to cells. Secondly, the TiSiN thin film promoted differentiation of human bone cells above the bare control Ti alloy as measured by alkaline phosphatase and calcium production. TiSiN thin films provide better corrosion resistance and protect the underlying metal from the corrosive environment. The thin film surface is both biocompatible and bioactive as indicated from the cytotoxicity and biomineralization studies. Copyright © 2017 Elsevier B.V. All rights reserved.

High frequency pulse anodising of magnetron sputtered Al–Zr and Al–Ti Coatings

DEFF Research Database (Denmark)

Gudla, Visweswara Chakravarthy; Bordo, Kirill; Engberg, Sara

2016-01-01

High frequency pulse anodising of Al–Zr and Al–Ti coatings is studied as a surface finishing technique and compared to conventional decorative DC anodising. The Al–Zr and Al–Ti coatings were deposited using DC magnetron sputtering and were heat treated after deposition to generate a multiphase mi...

EGFET pH Sensor Performance Dependence on Sputtered TiO2 Sensing Membrane Deposition Temperature

Directory of Open Access Journals (Sweden)

Khairul Aimi Yusof

2016-01-01

Full Text Available Titanium dioxide (TiO2 thin films were sputtered by radio frequency (RF magnetron sputtering method and have been employed as the sensing membrane of an extended gate field effect transistor (EGFET for pH sensing detection application. The TiO2 thin films were deposited onto indium tin oxide (ITO coated glass substrates at room temperature and 200°C, respectively. The effect of deposition temperature on thin film properties and pH detection application was analyzed. The TiO2 samples used as the sensing membrane for EGFET pH-sensor and the current-voltage (I-V, hysteresis, and drift characteristics were examined. The sensitivity of TiO2 EGFET sensing membrane was obtained from the transfer characteristic (I-V curves for different substrate heating temperatures. TiO2 thin film sputtered at room temperature achieved higher sensitivity of 59.89 mV/pH compared to the one deposited at 200°C indicating lower sensitivity of 37.60 mV/pH. Moreover the hysteresis and the drift of TiO2 thin film deposited at room temperature showed lower values compared to the one at 200°C. We have also tested the effect of operating temperature on the performance of the EGFET pH-sensing and found that the temperature effect was very minimal.

Mechanical properties and biocompatibility of the sputtered Ti doped hydroxyapatite.

Science.gov (United States)

Vladescu, A; Padmanabhan, S C; Ak Azem, F; Braic, M; Titorencu, I; Birlik, I; Morris, M A; Braic, V

2016-10-01

The hydroxyapatite enriched with Ti were prepared as possible candidates for biomedical applications especially for implantable devices that are in direct contact to the bone. The hydroxyapatites with different Ti content were prepared by RF magnetron sputtering on Ti-6Al-4V alloy using pure hydroxyapatite and TiO2 targets. The content of Ti was modified by changing the RF power fed on TiO2 target. The XPS and FTIR analyses revealed the presence of hydroxyapatite structure. The hardness and elastic modulus of the hydroxyapatite were increased by Ti addition. After 5 days of culture, the cell viability of the Ti-6Al-4V was enhanced by depositing with undoped or doped hydroxyapatite. The Ti additions led to an increase in cell viability of hydroxyapatite, after 5 days of culture. The electron microscopy showed the presence of more cells on the surface of Ti-enriched hydroxyapatite than those observed on the surface of the uncoated alloys or undoped hydroxyapatite. Copyright © 2016 Elsevier Ltd. All rights reserved.

Preparation of single-crystal TiC (111) by radio frequency magnetron sputtering at low temperature

International Nuclear Information System (INIS)

Qi, Q.; Zhang, W.Z.; Shi, L.Q.; Zhang, W.Y.; Zhang, W.; Zhang, B.

2012-01-01

Single-crystal films of TiC (111) have been synthesized at room temperature on Al 2 O 3 (0001) substrates by radio frequency magnetron sputtering using a compound Ti–C target. The substrate temperature and bias were varied to explore the influence of deposition parameters on the crystal structure. Both Al 2 O 3 (0001) and Si (100) substrates were used for epitaxial growth of TiC films. A series of characterizations of TiC films were carried out, including Rutherford backscattering spectroscopy, X-ray diffraction, Raman and X-ray photoelectron spectroscopy. Single-crystal films of TiC (111) on the Al 2 O 3 (0001) were demonstrated. - Highlights: ► Single-crystal films of TiC (111) have been synthesized by RF magnetron sputtering. ► Both temperature and bias affect greatly the TiC crystal structure. ► Al 2 O 3 substrate is much better than Si substrate for TiC epitaxial growth. ► TiC (111) epitaxial film can be grown on Al 2 O 3 (0001) at room temperature.

Characterization and tribocorrosion behavior of sputtered NiTi coatings

Energy Technology Data Exchange (ETDEWEB)

Jin, XiaoMin; Gao, Lizhen [Taiyuan University of Technology (China). College of Environmental Science and Engineering; Wang, Hefeng [Taiyuan University of Technology (China). College of Mechanics; Liu, Erqiang [Taiyuan University of Technology (China). Inst. of Applied Mechanics and Biomedical Engineering

2016-02-15

In this study, NiTi coatings were deposited onto AISI 316L stainless steel substrates by closed field unbalanced magnetron sputtering. The microstructure and properties of the coatings were characterized by means of X-ray diffraction, scanning electron microscopy, and nano-indentation. The tribocorrosion resistance and corrosion behavior of the stainless steel substrates and NiTi coatings were investigated in Hanks' solution. The experimental results indicated the NiTi coatings show higher corrosion polarization resistance and a more stable corrosion potential in the Hanks' solution than the uncoated stainless steel substrate. The NiTi coatings also exhibited excellent wear resistance and chemical stability in sliding tests with an Si{sub 3}N{sub 4} ball in the Hanks' solution. The tested samples showed different wear mechanisms in the sliding tests. Compared to the SS substrates, the NiTi coatings were more compatible with the Si{sub 3}N{sub 4} ball.

Effect of interfacial oxide thickness on the photocatalytic activity of magnetron-sputtered TiO2coatings on aluminum substrate

DEFF Research Database (Denmark)

Daviðsdóttir, Svava; Petit, Jean-Pierre; Shabadi, Rajashekhara

2015-01-01

The influence of the coating/substrate interface on the photocatalytic behavior of Al-TiO2 coatings was investigated. The TiO2 coatings were prepared by magnetron sputtering. The nanoscale structure of the coating was analyzed using X-ray diffraction; atomic force microscopy; scanning electron...... transport between the coating and the metallic substrate. The highest photocurrents were indeed obtained when the thickness of interfacial aluminum oxide could be reduced by sputtering a thin Ti layer prior to TiO2 coating. Photocurrent plotted for different photon energy for a TiO2 coating on a Ti...

Mn-coatings on the micro-pore formed Ti-29Nb-xHf alloys by RF-magnetron sputtering for dental applications

Science.gov (United States)

Park, Seon-Yeong; Choe, Han-Cheol

2018-02-01

In this study, Mn-coatings on the micro-pore formed Ti-29Nb-xHf alloys by RF-magnetrons sputtering for dental applications were studied using different experimental techniques. Mn coating films were formed on Ti-29Nb-xHf alloys by a radio frequency magnetron sputtering technique for 0, 1, 3, and 5 min at 45 W. The microstructure, composition, and phase structure of the coated alloys were examined by optical microscopy, field emission scanning electron microscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy. The microstructure of Ti-29Nb alloy showed α" phase in the needle-like structure and Ti-29Nb-15Hf alloy showed β phase in the equiaxed structure. As the sputtering time increased, the circular particles of Mn coatings on the Ti-29Nb alloy increased at inside and outside surfaces. As the sputtering time increased, [Mn + Ca/P] ratio of the plasma electrolytic oxidized films in Ti- 29Nb-xHf alloys increased. The corrosion potential (Ecorr) of Mn coatings on the Ti-29Nb alloy showed higher than that of Mn coatings on the Ti-29Nb-15Hf alloy. The passive current density (Ipass) of the Mn coating on the Ti-29Nb alloy and Mn coatings on the Ti-29Nb-15Hf alloy was less noble than the non-Mn coated Ti-29Nb and Ti-29Nb-15Hf alloys surface.

Controlled formation of anatase and rutile TiO2 thin films by reactive magnetron sputtering

NARCIS (Netherlands)

Rafieian Boroujeni, Damon; Ogieglo, Wojciech; Savenije, Tom; Lammertink, Rob G.H.

2015-01-01

We discuss the formation of TiO2 thin films via DC reactive magnetron sputtering. The oxygen concentration during sputtering proved to be a crucial parameter with respect to the final film structure and properties. The initial deposition provided amorphous films that crystallise upon annealing to

Construction of AgBr nano-cakes decorated Ti3+ self-doped TiO2 nanorods/nanosheets photoelectrode and its enhanced visible light driven photocatalytic and photoelectrochemical properties

Science.gov (United States)

Deng, Xiaoyong; Zhang, Huixuan; Guo, Ruonan; Cheng, Xiuwen; Cheng, Qingfeng

2018-05-01

In the study, AgBr nano-cakes decorated Ti3+ self-doped TiO2 nanorods/nanosheets (AgBr-Ti3+/TiO2 NRs/NSs) photoelectrode with enhanced visible light driven photocatalytic (PC) and photoelectrochemical (PECH) performance has been successfully fabricated by hydrothermal reaction, followed by sodium borohydride reduction and then successive ionic layer adsorption and reaction (SILAR) treatment. Afterwards, series of characterizations were conducted to study the physicochemical properties of AgBr-Ti3+/TiO2 NRs/NSs photoelectrode. Results indicated that AgBr nano-cakes with sizes varying from 110 to 180 nm were uniformly decorated on the surface of Ti3+/TiO2 NRs/NSs to form AgBr-Ti3+/TiO2 NRs/NSs photoelectrode. Moreover, PC activity of AgBr-Ti3+/TiO2 NRs/NSs photoelectrode was measured by degradation of methylene blue (MB). It was found that AgBr-Ti3+/TiO2 NRs/NSs photoelectrode exhibited higher PC activity (98.7%) than that of other samples within 150 min visible light illumination, owing to the enhancement of visible light harvesting and effective separation of photoproduced charges. Thus, AgBr nano-cakes and Ti3+ exerted a huge influence on the PC and PECH properties of AgBr-Ti3+/TiO2 NRs/NSs photoelectrode. Furthermore, the possible enhanced visible light driven PC mechanism of AgBr-Ti3+/TiO2 NRs/NSs was proposed and confirmed.

Controlled formation of anatase and rutile TiO2 thin films by reactive magnetron sputtering

Directory of Open Access Journals (Sweden)

Damon Rafieian

2015-09-01

Full Text Available We discuss the formation of TiO2 thin films via DC reactive magnetron sputtering. The oxygen concentration during sputtering proved to be a crucial parameter with respect to the final film structure and properties. The initial deposition provided amorphous films that crystallise upon annealing to anatase or rutile, depending on the initial sputtering conditions. Substoichiometric films (TiOx<2, obtained by sputtering at relatively low oxygen concentration, formed rutile upon annealing in air, whereas stoichiometric films formed anatase. This route therefore presents a formation route for rutile films via lower (<500 °C temperature pathways. The dynamics of the annealing process were followed by in situ ellipsometry, showing the optical properties transformation. The final crystal structures were identified by XRD. The anatase film obtained by this deposition method displayed high carriers mobility as measured by time-resolved microwave conductance. This also confirms the high photocatalytic activity of the anatase films.

Angular dependence of sputtering yield of TiSi sub 2 layers and analysis of titanium disilicide by SIMS and SCANIIR methods

Energy Technology Data Exchange (ETDEWEB)

Antonov, S L; Valiev, K A; Vasiliev, A G; Orlikovsky, A A [AN SSSR, Moscow (USSR). Inst. of Physics and Technology

1989-11-01

The values of sputtering yields of TiSi{sub 2}, Ti and Si layers are determined for Ar{sup +} (8 keV) bombardment at angles 0-80{sup 0}. It is shown that the theoretical functions that we have suggested for TiSi{sub 2} sputtering yields from angular Ar{sup +} bombardment, which are based on models of bicomponent compounds sputtering under normal ion bombardment, are in good agreement with the experimental curve for TiSi{sub 2}. The calibration curves for the determination of TiSi{sub x} layer compositions by SIMS and SCANIIR methods (in dynamic regime) are presented. It is shown with the help of the static SIMS method (E{sub AR+} = 3 keV) that not only can the TiSi{sub x} composition be determined but the TiSi{sub 2} crystal phase can also be identified. (author).

Cell adhesion on NiTi thin film sputter-deposited meshes

Energy Technology Data Exchange (ETDEWEB)

Loger, K. [Inorganic Functional Materials, Institute for Materials Science, Faculty of Engineering, University of Kiel (Germany); Engel, A.; Haupt, J. [Department of Cardiovascular Surgery, University Hospital of Schleswig-Holstein, Kiel (Germany); Li, Q. [Biocompatible Nanomaterials, Institute for Materials Science, Faculty of Engineering, University of Kiel (Germany); Lima de Miranda, R. [Inorganic Functional Materials, Institute for Materials Science, Faculty of Engineering, University of Kiel (Germany); ACQUANDAS GmbH, Kiel (Germany); Quandt, E. [Inorganic Functional Materials, Institute for Materials Science, Faculty of Engineering, University of Kiel (Germany); Lutter, G. [Department of Cardiovascular Surgery, University Hospital of Schleswig-Holstein, Kiel (Germany); Selhuber-Unkel, C. [Biocompatible Nanomaterials, Institute for Materials Science, Faculty of Engineering, University of Kiel (Germany)

2016-02-01

Scaffolds for tissue engineering enable the possibility to fabricate and form biomedical implants in vitro, which fulfill special functionality in vivo. In this study, free-standing Nickel–Titanium (NiTi) thin film meshes were produced by means of magnetron sputter deposition. Meshes contained precisely defined rhombic holes in the size of 440 to 1309 μm{sup 2} and a strut width ranging from 5.3 to 9.2 μm. The effective mechanical properties of the microstructured superelastic NiTi thin film were examined by tensile testing. These results will be adapted for the design of the holes in the film. The influence of hole and strut dimensions on the adhesion of sheep autologous cells (CD133 +) was studied after 24 h and after seven days of incubation. Optical analysis using fluorescence microscopy and scanning electron microscopy showed that cell adhesion depends on the structural parameters of the mesh. After 7 days in cell culture a large part of the mesh was covered with aligned fibrous material. Cell adhesion is particularly facilitated on meshes with small rhombic holes of 440 μm{sup 2} and a strut width of 5.3 μm. Our results demonstrate that free-standing NiTi thin film meshes have a promising potential for applications in cardiovascular tissue engineering, particularly for the fabrication of heart valves. - Highlights: • Freestanding NiTi thin film scaffolds were fabricated with magnetron sputtering process. • Effective mechanical properties of NiTi scaffolds can be adapted by the mesh structure parameters. • Cell adhesion on the NiTi thin film scaffold is controlled by the structure parameters of the mesh. • Cells strongly adhere after seven days and form a confluent layer on the mesh.

Cell adhesion on NiTi thin film sputter-deposited meshes

International Nuclear Information System (INIS)

Loger, K.; Engel, A.; Haupt, J.; Li, Q.; Lima de Miranda, R.; Quandt, E.; Lutter, G.; Selhuber-Unkel, C.

2016-01-01

Scaffolds for tissue engineering enable the possibility to fabricate and form biomedical implants in vitro, which fulfill special functionality in vivo. In this study, free-standing Nickel–Titanium (NiTi) thin film meshes were produced by means of magnetron sputter deposition. Meshes contained precisely defined rhombic holes in the size of 440 to 1309 μm 2 and a strut width ranging from 5.3 to 9.2 μm. The effective mechanical properties of the microstructured superelastic NiTi thin film were examined by tensile testing. These results will be adapted for the design of the holes in the film. The influence of hole and strut dimensions on the adhesion of sheep autologous cells (CD133 +) was studied after 24 h and after seven days of incubation. Optical analysis using fluorescence microscopy and scanning electron microscopy showed that cell adhesion depends on the structural parameters of the mesh. After 7 days in cell culture a large part of the mesh was covered with aligned fibrous material. Cell adhesion is particularly facilitated on meshes with small rhombic holes of 440 μm 2 and a strut width of 5.3 μm. Our results demonstrate that free-standing NiTi thin film meshes have a promising potential for applications in cardiovascular tissue engineering, particularly for the fabrication of heart valves. - Highlights: • Freestanding NiTi thin film scaffolds were fabricated with magnetron sputtering process. • Effective mechanical properties of NiTi scaffolds can be adapted by the mesh structure parameters. • Cell adhesion on the NiTi thin film scaffold is controlled by the structure parameters of the mesh. • Cells strongly adhere after seven days and form a confluent layer on the mesh.

Intrinsic anomalous surface roughening of TiN films deposited by reactive sputtering

International Nuclear Information System (INIS)

Auger, M. A.; Vazquez, L.; Sanchez, O.; Cuerno, R.; Castro, M.; Jergel, M.

2006-01-01

We study surface kinetic roughening of TiN films grown on Si(100) substrates by dc reactive sputtering. The surface morphology of films deposited for different growth times under the same experimental conditions were analyzed by atomic force microscopy. The TiN films exhibit intrinsic anomalous scaling and multiscaling. The film kinetic roughening is characterized by a set of local exponent values α loc =1.0 and β loc =0.39, and global exponent values α=1.7 and β=0.67, with a coarsening exponent of 1/z=0.39. These properties are correlated to the local height-difference distribution function obeying power-law statistics. We associate this intrinsic anomalous scaling with the instability due to nonlocal shadowing effects that take place during thin-film growth by sputtering

Crystal Structure And Optical Properties Of TiO2 Thin Films Prepared By Reactive RF Magnetron Sputtering

Directory of Open Access Journals (Sweden)

Goto S.

2015-06-01

Full Text Available In sputtering deposition process of TiO2, metal Ti or sintered TiO2 target is used as deposition source. In this study, we have compared the characteristic of target materials. When TiO2 target was used, stoichiometric TiO2 films was deposited under the Ar atmosphere containing 1.0% of oxygen. The highest sputtering rate under this atmosphere was 3.9nm/min at 3.4W/cm2. But, sintered TiO2 target is fragile and cannot endure higher density of input power than 3.4W/cm2. On the other hand, Ti target needs higher oxygen concentration (8% in sputtering gas atmosphere for obtaining rutile/anatase. Even though Ti target can be input twice power density of 7.9W/cm2, the highest deposition rate for Ti target was 1.4/nm, which was ~35% of the highest rate for TiO2 target. Then we have study out the composite target consisting of Ti plate and TiO2 chips. Using the composite target, stoichiometric TiO2 films were prepared in the rate of 9.6nm/min at 6.8 W/cm2 under the atmosphere of Ar/2.5%O2. Furthermore, we have found that the TiO2 films obtained from the composite target consisted of about 100% anatase, whereas TiO2 films obtained from other target have rutile dominant structure. The optical band gap energy of the film is determined by using the Tauc plot. The calculated band gap energies for the films deposited by Ti target and composite target were 2.95 and 3.24eV, which are equivalent to that of rutile and anatase structure, respectively.

Physical and chemical characterization of Ag-doped Ti coatings produced by magnetron sputtering of modular targets

International Nuclear Information System (INIS)

Schmitz, Tobias; Warmuth, Franziska; Werner, Ewald; Hertl, Cornelia; Groll, Jürgen; Gbureck, Uwe; Moseke, Claus

2014-01-01

Silver-doped Ti films were produced using a single magnetron sputtering source equipped with a titanium target containing implemented silver modules under variation of bias voltage and substrate temperature. The Ti(Ag) films were characterized regarding their morphology, contact angle, phase composition, silver content and distribution as well as the elution of Ag + ions into cell media. SEM and AFM pictures showed that substrate heating during film deposition supported the formation of even and dense surface layers with small roughness values, an effect that could even be enforced, when a substrate bias voltage was applied instead. The deposition of both Ti and Ag was confirmed by X-ray diffraction. ICP-MS and EDX showed a clear correlation between the applied sputtering parameters and the silver content of the coatings. Surface-sensitive XPS measurements revealed that higher substrate temperatures led to an accumulation of Ag in the near-surface region, while the application of a bias voltage had the opposite effect. Additional elution measurements using ICP-MS showed that the release kinetics depended on the amount of silver located at the film surface and hence could be tailored by variation of the sputter parameters. - Highlights: • Modular targets were used to deposit Ti(Ag) films. • Ag-content is adjustable by bias voltage, sputtering power and substrate temperature. • Coating parameters significantly change film morphology and roughness. • A critical parameter for Ag release is the fraction of silver on the film surface

Microfabricated Cantilevers Based on Sputtered Thin-Film Ni50Ti50 Shape Memory Alloy (SMA)

Science.gov (United States)

2015-08-01

surface coating developed during the NiTi deposition or anneal that is relatively resistant to the wet etch. Fig. 2 SEMs after the NiTi wet -etch...SEMs of NiTi devices after the 600 °C anneal , wet -etch patterning of the NiTi. A 120-nm Au capping layer was also sputtered. Figure 3a shows a 200-nm...Ni50Ti50 Cantilever 2 3. Results and Discussion 3 3.1 Wet -Etch Patterning NiTi 3 3.2 Dry-Etch Release of NiTi Devices 5 3.3 Thermal Actuation of

Enhancement in dye-sensitized solar cells based on MgO-coated TiO2 electrodes by reactive DC magnetron sputtering

International Nuclear Information System (INIS)

Wu Sujuan; Han Hongwei; Tai Qidong; Zhang Jing; Xu Sheng; Zhou Conghua; Yang Ying; Hu Hao; Chen Bolei; Sebo, Bobby; Zhao Xingzhong

2008-01-01

A surface modification method was carried out by reactive DC magnetron sputtering to fabricate TiO 2 electrodes coated with insulating MgO for dye-sensitized solar cells. The MgO-coated TiO 2 electrode had been characterized by x-ray photoelectron spectroscopy (XPS), energy-dispersive x-ray spectroscopy (EDX), scanning electron microscopy (SEM), UV-vis spectrophotometer, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The study results revealed that the TiO 2 modification increases dye adsorption, decreases trap states and suppresses interfacial recombination. The effects of sputtering MgO for different times on the performance of DSSCs were investigated. It indicated that sputtering MgO for 3 min on TiO 2 increases all cell parameters, resulting in increasing efficiency from 6.45% to 7.57%

Fabrication and characterization of metal–semiconductor–metal ultraviolet photodetector based on rutile TiO{sub 2} nanorod

Energy Technology Data Exchange (ETDEWEB)

Selman, Abbas M., E-mail: alabbasiabbas@yahoo.co.uk [Nano-Optoelectronics Research and Technology Laboratory (N.O.R.), School of Physics, Universiti Sains Malaysia, Penang 11800 (Malaysia); Department of Pharmacology and Toxicology, College of Pharmacy, University of Kufa, Najaf (Iraq); Hassan, Z. [Nano-Optoelectronics Research and Technology Laboratory (N.O.R.), School of Physics, Universiti Sains Malaysia, Penang 11800 (Malaysia)

2016-01-15

The fabrication and characterization of a metal–semiconductor–metal ultraviolet photodetector are studied. The photodetector is based on TiO{sub 2} nanorods (NRs) grown on p-type (1 1 1)-oriented silicon substrate seeded with a TiO{sub 2} layer is synthesized by radio frequency reactive magnetron sputtering. A chemical bath deposition is used to grow TiO{sub 2} NRs on Si substrate. The structural and optical properties of the obtained sample are analyzed by using X-ray diffraction and field emission-scanning electron microscopy. Results show a tetragonal rutile structure of the synthesized TiO{sub 2} NRs. Optical properties are further examined using photoluminescence spectroscopy. A sharp and high-intensity UV peak at 367 nm is observed in comparison with visible defect peaks centered at 432 and 718 nm. Upon exposure to 365 nm light (2.3 mW/cm) at 5 V bias, the device displays 76.06 × 10{sup 2} sensitivity, internal photodetector gain of 77.06, photocurrent of the device is 2.62 × 10{sup −5} A and photoresponse peak of 69.7 mA/W. The response and recovery times are calculated as 18.5 and 19.1 ms upon illumination to a pulse UV light (365 nm, 2.3 mW/cm{sup 2}) at 5 V applied bias. These results demonstrate that the fabricated high-quality photodiode is a promising candidate as a low-cost UV photodetector for commercially-integrated photoelectronic applications.

Advanced TiC/a-C: H nanocomposite coatings deposited by magnetron sputtering

OpenAIRE

Pei, Y.T.; Galvan, D.; Hosson, J.Th.M. De; Strondl, C.

2006-01-01

TiC/a-C:H nanocomposite coatings have been deposited by magnetron Sputtering. They consist of 2-5 nm TiC nanocrystallites embedded in the amorphous hydrocarbon (a-C:H) matrix. A transition from a Columnar to a glassy microstructure has been observed in the nanocomposite coatings with increasing substrate bias or carbon content. Micro-cracks induced by nanoindentation or wear tests readily propagate through the column boundaries whereas the coatings without a columnar inicrostructure exhibit s...

Tuning silver ion release properties in reactively sputtered Ag/TiOx nanocomposites

Science.gov (United States)

Xiong, J.; Ghori, M. Z.; Henkel, B.; Strunskus, T.; Schürmann, U.; Deng, M.; Kienle, L.; Faupel, F.

2017-07-01

Silver/titania nanocomposites with strong bactericidal effects and good biocompatibility/environmental safety show a high potential for antibacterial applications. Tailoring the silver ion release is thus highly promising to optimize the antibacterial properties of such coatings and to preserve biocompatibility. Reactive sputtering is a fast and versatile method for the preparation of such Ag/TiOx nanocomposites coatings. The present work is concerned with the influence of sputter parameters on the surface morphology and silver ion release properties of reactively sputtered Ag/TiOx nanocomposites coatings showing a silver nanoparticle size distribution in the range from 1 to 20 nm. It is shown that the silver ion release rate strongly depends on the total pressure: the coatings prepared at lower pressure present a lower but long-lasting release behavior. The much denser structure produced under these conditions reduces the transport of water molecules into the coating. In addition, the influence of microstructure and thickness of titanium oxide barriers on the silver ion release were investigated intensively. Moreover, for the coatings prepared at high total pressure, it was demonstrated that stable and long-lasting silver release can be achieved by depositing a barrier with a high rate. Nanocomposites produced under these conditions show well controllable silver ion release properties for applications as antibacterial coatings.

TiCx thin films coatings prepared by reactive sputtering

International Nuclear Information System (INIS)

Saoula, N.; Handa, K.; Kesri, R.

2004-01-01

Full text.Transition metal carbides and nitrides attract large technological interest due to their unique properties like high hardness and young modulus, high electric conductivity, a considerable high-temperature strength, high corrosion resistance and high melting or decomposition temperatures. They have been applied as coatings for tools because of their superior properties. these materials have such properties due to atomic bonding, which shows a mixed covalent, metallic and ionic character. Among these nitrides and carbides titanium carbide is a compound of particular importance. Titanium carbide combines the advantages of a high melting point (3140 celsius degree) and hardness (3000 Hv) with those of relative lightness (density 4.93 10 3 Kg m -3 ).It also exhibits high resistance to both corrosion and oxidation and a relatively low friction coefficient. Usually, TiC films are produced by deposition with plasma-enhanced CVD (PCVD), thermal chemical vapour deposition (CVD) or activated reactive evaporation methods. However, these methods require high temperature (>600 celsius degree) substrates to achieve the deposition, which sometimes causes thermal damage to the deposited films. At temperature above 550 celsius degree, thermal diffusion of materials not suitable may also occur. In addition, it has been reported that the maximum temperature which permits the appropriate coating of hardened steel tools is 500 celsius degree. Therefore, it is desirable to develop a deposition technique for TiC films using low-temperature substrates to avoid thermal damage. So, different physical vapour deposition (PVD) processes for deposition of TiC at relatively low temperatures have been used through the years. These processes are based on vaporisation of titanium in hydrocarbon atmosphere or on sputtering of solid TiC target or titanium target in hydrocarbon atmosphere. the most often-used hydrocarbon gases are methane, acetylene, ethene and ethane. In previous works, we

Preparation and characterization of self-assembled percolative BaTiO3–CoFe2O4 nanocomposites via magnetron co-sputtering

Directory of Open Access Journals (Sweden)

Qian Yang

2014-04-01

Full Text Available BaTiO3–CoFe2O4 composite films were prepared on (100 SrTiO3 substrates by using a radio-frequency magnetron co-sputtering method at 750 °C. These films contained highly (001-oriented crystalline phases of perovskite BaTiO3 and spinel CoFe2O4, which can form a self-assembled nanostructure with BaTiO3 well-dispersed into CoFe2O4 under optimized sputtering conditions. A prominent dielectric percolation behavior was observed in the self-assembled nanocomposite. Compared with pure BaTiO3 films sputtered under similar conditions, the nanocomposite film showed higher dielectric constants and lower dielectric losses together with a dramatically suppressed frequency dispersion. This dielectric percolation phenomenon can be explained by the 'micro-capacitor' model, which was supported by measurement results of the electric polarization and leakage current.

Reactive sputtering of TiN films at large substrate to target distances

International Nuclear Information System (INIS)

Musil, J.; Kadlec, S.

1990-01-01

This paper is a critical review of the present status of the magnetron ion sputter plating of thin CiN films. Thus different possibilities of extracting high ion currents 1 s from the magnetron discharge to substrates located not only at standard target to substrate distances d S-T of about 50 mm but also at larger distances d S-T are discussed in detail. Special attention is devoted to magnetron sputtering systems with enhanced ionization, to plasma confinement in the magnetron sputtering systems and to the discharge characteristics of an unbalanced magnetron (UM). It is shown that a UM can be operated in the regime of a double-site-sustained discharge (DSSD) and in this case large 1 s can be extracted to substrates located in large D S-T of about 200 mm and even at high pressures p = 5 Pa. A physical comparison of the conventional magnetron (CM), UM and DSSD is also given. Considerable attention is also devoted to the effect of ion bombardment on properties of TiN films created in the sputtering system using DSSD. (author)

Effect of gas ratio on tribological properties of sputter deposited TiN coatings

Energy Technology Data Exchange (ETDEWEB)

Chavda, Mahesh R., E-mail: maheshchavda1990@gmail.com [Department of Mechanical Engineering, Dr. Jivraj Mehta Institute of Technology, Mogar-388340 (India); Chauhan, Kamlesh V.; Rawal, Sushant K., E-mail: sushantrawal.me@charusat.ac.in [CHAMOS Matrusanstha Department of Mechanical Engineering, Chandubhai S. Patel Institute of Technology, Charotar University of Science and Technology (CHARUSAT), Changa-388421 (India)

2016-05-06

Titanium nitride (TiN) coatings were deposited on Si, corning glass, pins of mild steel (MS, ϕ3mm), aluminium (Al, ϕ4mm) and brass (ϕ6mm) substratesby DC magnetron sputtering. The argon and nitrogen (Ar:N{sub 2})gas ratio was precisely controlled by Mass Flow Controller (MFC) and was varied systematically at diffract values of 10:10,12:08, 16:04 and 18:02sccm. The structural properties of TiN coatings were characterized by X-ray diffraction (XRD) and its surface topography was studied using field emission scanning electron microscopy (FE-SEM). The tribological properties of TiN coatings were investigated using pin-on-disc tribometer.

Capability of Sputtered Micro-patterned NiTi Thick Films

Science.gov (United States)

Bechtold, Christoph; Lima de Miranda, Rodrigo; Quandt, Eckhard

2015-09-01

Today, most NiTi devices are manufactured by a combination of conventional metal fabrication steps, e.g., melting, extrusion, cold working, etc., and are subsequently structured by high accuracy laser cutting. This combination has been proven to be very successful; however, there are several limitations to this fabrication route, e.g., in respect to the fabrication of more complex device designs, device miniaturization or the combination of different materials for the integration of further functionality. These issues have to be addressed in order to develop new devices and applications. The fabrication of micro-patterned films using magnetron sputtering, UV lithography, and wet etching has great potential to overcome limitations of conventional device manufacturing. Due to its fabrication characteristics, this method allows the production of devices with complex designs, high structural accuracy, smooth edge profile, at layer thicknesses up to 75 µm. The aim of this study is to present recent developments in the field of NiTi thin film technology, its advantages and limitations, as well as new possible applications in the medical and in non-medical fields. These developments include among others NiTi scaffold structures covered with NiTi membranes for their potential use as filters, heart valve components or aneurysm treatments, as well as micro-actuators for consumable electronics or automotive applications.

Microporous TiO2-WO3/TiO2 films with visible-light photocatalytic activity synthesized by micro arc oxidation and DC magnetron sputtering

International Nuclear Information System (INIS)

Wu, Kee-Rong; Hung, Chung-Hsuang; Yeh, Chung-Wei; Wu, Jiing-Kae

2012-01-01

Highlights: ► A simple MAO is used to prepare porous WO 3 /TiO 2 layer on Ti sheet as a visible-light enabled catalyst. ► The photocatalytic activity of the WO 3 /TiO 2 is enhanced by sputtering over an N,C-TiO 2 layer. ► This is ascribed to the synergetic effect of hybrid sample prepared by two-step method. - Abstract: This study reports the preparation of microporous TiO 2 -WO 3 /TiO 2 films with a high surface area using a two-step approach. A porous WO 3 /TiO 2 template was synthesized by oxidizing a titanium sheet using a micro arc oxidation (MAO) process. This sheet was subsequently overlaid with a visible light (Vis)-enabled TiO 2 (N,C-TiO 2 ) film, which was deposited by codoping nitrogen (N) and carbon (C) ions into a TiO 2 lattice using direct current magnetron sputtering. The resulting microporous TiO 2 -WO 3 /TiO 2 film with a 0.38-μm-thick N,C-TiO 2 top-layer exhibited high photocatalytic activity in methylene blue (MB) degradation among samples under ultraviolet (UV) and Vis irradiation. This is attributable to the synergetic effect of two-step preparation method, which provides a highly porous microstructure and the well-crystallized N,C-TiO 2 top-layer. This is because a higher surface area with high crystallinity favors the adsorption of more MB molecules and more photocatalytic active areas. Thus, the microporous TiO 2 -WO 3 /TiO 2 film has promising applications in the photocatalytic degradation of dye solution under UV and Vis irradiation. These results imply that the microporous WO 3 /TiO 2 can be used as a template of hybrid electrode because it enables rapid fabrication.

Defects, stoichiometry, and electronic transport in SrTiO{sub 3-δ} epilayers: A high pressure oxygen sputter deposition study

Energy Technology Data Exchange (ETDEWEB)

Ambwani, P.; Xu, P.; Jeong, J. S.; Deng, R.; Mkhoyan, K. A.; Jalan, B.; Leighton, C., E-mail: leighton@umn.edu [Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455 (United States); Haugstad, G. [Characterization Facility, University of Minnesota, Minneapolis, Minnesota 55455 (United States)

2016-08-07

SrTiO{sub 3} is not only of enduring interest due to its unique dielectric, structural, and lattice dynamical properties, but is also the archetypal perovskite oxide semiconductor and a foundational material in oxide heterostructures and electronics. This has naturally focused attention on growth, stoichiometry, and defects in SrTiO{sub 3}, one exciting recent development being such precisely stoichiometric defect-managed thin films that electron mobilities have finally exceeded bulk crystals. This has been achieved only by molecular beam epitaxy, however (and to a somewhat lesser extent pulsed laser deposition (PLD)), and numerous open questions remain. Here, we present a study of the stoichiometry, defects, and structure in SrTiO{sub 3} synthesized by a different method, high pressure oxygen sputtering, relating the results to electronic transport. We find that this form of sputter deposition is also capable of homoepitaxy of precisely stoichiometric SrTiO{sub 3}, but only provided that substrate and target preparation, temperature, pressure, and deposition rate are carefully controlled. Even under these conditions, oxygen-vacancy-doped heteroepitaxial SrTiO{sub 3} films are found to have carrier density, mobility, and conductivity significantly lower than bulk. While surface depletion plays a role, it is argued from particle-induced X-ray emission (PIXE) measurements of trace impurities in commercial sputtering targets that this is also due to deep acceptors such as Fe at 100's of parts-per-million levels. Comparisons of PIXE from SrTiO{sub 3} crystals and polycrystalline targets are shown to be of general interest, with clear implications for sputter and PLD deposition of this important material.

Effect of ion plating TiN on the oxidation of sputtered NiCrAlY-coated Ti3Al-Nb in air at 850-950 C

International Nuclear Information System (INIS)

Rizzo, F.C.; Zeng, C.; Chinese Academy of Sciences, Shenyang; Wu, W.

1998-01-01

A single sputtered NiCrAlY coating and a complex coating of inner ion-plated TiN and outer sputtered NiCrAlY were prepared on the intermetallic compound Ti 3 Al-Nb. Their oxidation behavior was examined at 850, 900, and 950 C in air by thermal gravimetry combined with XRD, SEM, and EDAX. The results showed that Ti 3 Al-Nb followed approximately parabolic oxidation, forming an outer thin Al 2 O 3 -rich scale and an inner TiO 2 -rich layer doped with Nb at the three temperatures. The TiO 2 -rich layer doped with Nb dominated the oxidation reaction. The single NiCrAlY coating did not follow parabolic oxidation exactly at 850 and 950 C, but oxidized approximately in a parabolic manner, because the instantaneous parabolic constants changed slightly with time. Besides the Al 2 O 3 scale, TiO 2 formed from the coating surface at the coating-substrate interface. The deterioration of the coating accelerated with increasing temperature. The NiCrAlY-TiN coating showed two-stage parabolic oxidation at 850 and 900 C, and an approximate parabolic oxidation at 950 C. The TiN layer was effective as a barrier to inhibit coating-alloy interdiffusion

Optical and structural properties of TiO2/Ti/Ag/TiO2 and TiO2/ITO/Ag/ITO/TiO2 metal-dielectric multilayers by RF magnetron sputtering for display application

International Nuclear Information System (INIS)

Lee, Jang-Hoon; Lee, Seung-Hyu; Hwangbo, Chang-Kwon; Lee, Kwang-Su

2004-01-01

Electromagnetic-interference (EMI) shielding and near-infrared (NIR) cutoff filters for plasma display panels, based on fundamental structures (ITO/Ag/ITO), (TiO 2 /Ti/Ag/TiO 2 ) and (TiO 2 /ITO/Ag/ITO/TiO 2 ), were designed and prepared by RF-magnetron sputtering. The optical, structural and electrical properties of the filters were investigated by using spectrophotometry, Auger electron spectroscopy, X-ray photoelectron spectroscopy, Rutherford backscattering spectroscopy, atomic force microscopy and four-point-probe measurements. The results show that ITO films as the barriers and base layers lead to higher transmittance in the visible spectrum and smoother surface roughness than Ti metal barriers, while maintaining high NIR cutoff characteristics and chemical stability, which may be attributed to the lower absorption in the interfacial layers and better protection of the Ag layers by the ITO layers.

Synthesis and characterization of TiO2/CdS core–shell nanorod arrays and their photoelectrochemical property

International Nuclear Information System (INIS)

Cao Chunlan; Hu Chenguo; Shen Weidong; Wang, Shuxia; Tian Yongshu; Wang Xue

2012-01-01

Highlights: ► TiO 2 /CdS core–shell nanorod arrays were fabricated by spin-SILAR method. ► The enhanced photocurrent was found in the TiO 2 /CdS core–shell nanorod arrays. ► The CdS coated on TiO 2 increases the e-h separation and enlarges light absorption range. - Abstract: TiO 2 /CdS core–shell nanorod arrays have been fabricated via a two-step method. Vertically aligned TiO 2 nanorod arrays (NRs) were synthesized by a facile hydrothermal method, and followed by depositing CdS nanoparticles on TiO 2 NRs by spin-coating successive ion layer adsorption and reaction (spin-SILAR) method. The surface morphology, structure, optical and photoelectrochemical behaviors of the core–shell NRs films are considered. The UV–vis absorption spectrum results suggested that the absorption peak of the TiO 2 /CdS core–shell NRs shifts from the ultraviolet region to the visible region in comparison to that of the pure TiO 2 NRs. The obviously enhanced photoelectrochemical (PEC) performances of the heterojunction NRs were found under illumination of the simulated sunlight in comparison with that of the TiO 2 NRs. The enhanced PEC performance and formation mechanism of TiO 2 /CdS core–shell NRs were discussed in detail.

Optimization of charge transfer and transport processes at the CdSe quantum dots/TiO2 nanorod interface by TiO2 interlayer passivation

International Nuclear Information System (INIS)

Jaramillo-Quintero, O A; Rincon, M E; Triana, M A

2017-01-01

Surface trap states hinder charge transfer and transport properties in TiO 2 nanorods (NRs), limiting its application on optoelectronic devices. Here, we study the interfacial processes between rutile TiO 2 NR and CdSe quantum dots (QDs) using TiO 2 interlayer passivation treatments. Anatase or rutile TiO 2 thin layers were deposited on an NR surface by two wet-chemical deposition treatments. Reduced interfacial charge recombination between NRs and CdSe QDs was observed by electrochemical impedance spectroscopy with the introduction of TiO 2 thin film interlayers compared to bare TiO 2 NRs. These results can be ascribed to in-gap trap state passivation of the TiO 2 NR surface, which led to an increase in open circuit voltage. Moreover, the rutile thin layer was more efficient than anatase to promote a higher photo-excited electron transfer from CdSe QDs to TiO 2 NRs due to a large driving force for charge injection, as confirmed by surface photovoltage spectroscopy. (paper)

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

Thin TiO2 films deposited by implantation and sputtering in RF inductively coupled plasmas

International Nuclear Information System (INIS)

Valencia-Alvarado, R; López-Callejas, R; Barocio, S R; Mercado-Cabrera, A; Peña-Eguiluz, R; Muñoz-Castro, A E; Rodríguez-Méndez, B G; De la Piedad-Beneitez, A; De la Rosa-Vázquez, J M

2012-01-01

The achievement of titanium dioxide (TiO 2 ) thin films in the rutile crystalline phase is reported. The samples result from the implantation of oxygen ions of Ti in argon/oxygen plasma generated by inductively coupled RF at a commercial 13.56 MHz frequency. Simultaneously, a sputtering process is conducted on the titanium target in order to produce TiO 2 thin films in the anatase phase over silicon and glass substrates. Both implantation and sputtering processes shared the same 500 W plasma with the target, polarized between 0 and -3 kV. The substrates were placed between 2 and 3 cm from the target, this distance being found to be determinant of the TiO 2 deposition rate. The rutile phase in the target was obtained at temperatures in the order of 680 degrees C and the anatase (unbiased) one at about 300 degrees C without any auxiliary heating. The crystalline phases were characterized by x ray diffraction and Raman spectroscopy. The morphology and average roughness were established by means of scanning electronic and atomic force microscopy, whereas the reaction products generated during the oxidation process were analyzed by mass spectrometry. Finally, the stoichiometric composition was measured by means of X-ray photoelectron spectroscopy.

Additive manufactured Ti6Al4V scaffolds with the RF- magnetron sputter deposited hydroxyapatite coating

International Nuclear Information System (INIS)

Chudinova, E; Surmeneva, M; Surmenev, R; Koptioug, A; Scoglund, P

2016-01-01

Present paper reports on the results of surface modification of the additively manufactured porous Ti6Al4V scaffolds. Radio frequency (RF) magnetron sputtering was used to modify the surface of the alloy via deposition of the biocompatible hydroxyapatite (HA) coating. The surface morphology, chemical and phase composition of the HA-coated alloy were studied. It was revealed that RF magnetron sputtering allows preparing a homogeneous HA coating onto the entire surface of scaffolds. (paper)

Interfacial Structure and Photocatalytic Activity of Magnetron Sputtered TiO2 on Conducting Metal Substrates

DEFF Research Database (Denmark)

Daviðsdóttir, Svava; Petit, Jean-Pierre; Mermoux, Michel

2014-01-01

The photocatalytic behavior of magnetron sputtered anatase TiO2 coatings on copper, nickel, and gold was investigated with the aim of understanding the effect of the metallic substrate and coating-substrate interface structure. Stoichiometry and nanoscale structure of the coating were investigated...

Time-resolved investigation of dual high power impulse magnetron sputtering with closed magnetic field during deposition of Ti-Cu thin films

International Nuclear Information System (INIS)

Stranak, Vitezslav; Hippler, Rainer; Cada, Martin; Hubicka, Zdenek; Tichy, Milan

2010-01-01

Time-resolved comparative study of dual magnetron sputtering (dual-MS) and dual high power impulse magnetron sputtering (dual-HiPIMS) systems arranged with closed magnetic field is presented. The dual-MS system was operated with a repetition frequency 4.65 kHz (duty cycle ≅50%). The frequency during dual-HiPIMS is lower as well as its duty cycle (f=100 Hz, duty 1%). Different metallic targets (Ti, Cu) and different cathode voltages were applied to get required stoichiometry of Ti-Cu thin films. The plasma parameters of the interspace between magnetrons in the substrate position were investigated by time-resolved optical emission spectroscopy, Langmuir probe technique, and measurement of ion fluxes to the substrate. It is shown that plasma density as well as ion flux is higher about two orders of magnitude in dual-HiPIMS system. This fact is partially caused by low diffusion of ionized sputtered particles (Ti + ,Cu + ) which creates a preionized medium.

Synthesis and characterization of TiO{sub 2}/CdS core-shell nanorod arrays and their photoelectrochemical property

Energy Technology Data Exchange (ETDEWEB)

Cao Chunlan [Department of Applied Physics, Chongqing University, Chongqing 400044 (China); Department of Power Engineer, Chongqing Communication College, Chongqing 400035 (China); Hu Chenguo, E-mail: hucg@cqu.edu.cn [Department of Applied Physics, Chongqing University, Chongqing 400044 (China); Shen Weidong [Department of Power Engineer, Chongqing Communication College, Chongqing 400035 (China); Wang, Shuxia [Department of Applied Physics, Chongqing University, Chongqing 400044 (China); Tian Yongshu [Department of Applied Physics, Chongqing University, Chongqing 400044 (China); Department of Power Engineer, Chongqing Communication College, Chongqing 400035 (China); Wang Xue [Department of Applied Physics, Chongqing University, Chongqing 400044 (China)

2012-05-15

Highlights: Black-Right-Pointing-Pointer TiO{sub 2}/CdS core-shell nanorod arrays were fabricated by spin-SILAR method. Black-Right-Pointing-Pointer The enhanced photocurrent was found in the TiO{sub 2}/CdS core-shell nanorod arrays. Black-Right-Pointing-Pointer The CdS coated on TiO{sub 2} increases the e-h separation and enlarges light absorption range. - Abstract: TiO{sub 2}/CdS core-shell nanorod arrays have been fabricated via a two-step method. Vertically aligned TiO{sub 2} nanorod arrays (NRs) were synthesized by a facile hydrothermal method, and followed by depositing CdS nanoparticles on TiO{sub 2} NRs by spin-coating successive ion layer adsorption and reaction (spin-SILAR) method. The surface morphology, structure, optical and photoelectrochemical behaviors of the core-shell NRs films are considered. The UV-vis absorption spectrum results suggested that the absorption peak of the TiO{sub 2}/CdS core-shell NRs shifts from the ultraviolet region to the visible region in comparison to that of the pure TiO{sub 2} NRs. The obviously enhanced photoelectrochemical (PEC) performances of the heterojunction NRs were found under illumination of the simulated sunlight in comparison with that of the TiO{sub 2} NRs. The enhanced PEC performance and formation mechanism of TiO{sub 2}/CdS core-shell NRs were discussed in detail.

Synthesis of ZnO nanorods-Au nanoparticles hybrids via in-situ plasma sputtering-assisted method for simultaneous electrochemical sensing of ascorbic acid and uric acid

Energy Technology Data Exchange (ETDEWEB)

Hou, Chao [College of Life Information Science & Instrument Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China); Liu, Hongying, E-mail: liuhongying@hdu.edu.cn [College of Life Information Science & Instrument Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China); State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry & Chemical Engineering, Nanjing University, Nanjing 210093 (China); Zhang, Dan; Yang, Chi [Department of Pharmacy, Nantong University, Nantong 226001 (China); Zhang, Mingzhen [College of Life Information Science & Instrument Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China)

2016-05-05

In this study, ZnO nanorods-Au nanoparticles (ZnO NRs-Au NPs) hybrids were prepared using an in-situ plasma sputtering-assisted method without any template. Characterization results from scanning electron microscopy, high-resolution transmission electron microscopy, and energy dispersive X-ray spectroscopy showed that Au NPs are highly dispersed and tightly anchored on the surface of ZnO NRs. The size and surface coverage of Au NPs were well controlled by plasma sputtering time. Moreover, the hybrids exhibited excellent electrocatalytic properties towards oxidation of ascorbic acid (AA) and uric acid (UA) due to large surface area of Au NPs and ZnO NRs, and thus can be used as electrochemical sensors. Differential pulse voltammetry results showed that AA and UA could be detected simultaneously by ZnO NRs-Au NPs hybrids modified glassy carbon electrode. The linear ranges for AA and UA are 0.1 to 4 mM and 0.01 to 0.4 mM, respectively. The results suggest promising future applications in clinical diagnosis. - Highlights: • ZnO nanorods-Au nanoparticles were synthesized by in-situ plasma sputtering method. • Influence of sputtering time on the formation of Au nanoparticles was studied. • It exhibited a strong electrocatalytic activity toward the oxidation of ascorbic acid and uric acid. • A portable and cheap approach for simultaneous detection of ascorbic acid and uric acid was developed.

Synthesis of ZnO nanorods-Au nanoparticles hybrids via in-situ plasma sputtering-assisted method for simultaneous electrochemical sensing of ascorbic acid and uric acid

International Nuclear Information System (INIS)

Hou, Chao; Liu, Hongying; Zhang, Dan; Yang, Chi; Zhang, Mingzhen

2016-01-01

In this study, ZnO nanorods-Au nanoparticles (ZnO NRs-Au NPs) hybrids were prepared using an in-situ plasma sputtering-assisted method without any template. Characterization results from scanning electron microscopy, high-resolution transmission electron microscopy, and energy dispersive X-ray spectroscopy showed that Au NPs are highly dispersed and tightly anchored on the surface of ZnO NRs. The size and surface coverage of Au NPs were well controlled by plasma sputtering time. Moreover, the hybrids exhibited excellent electrocatalytic properties towards oxidation of ascorbic acid (AA) and uric acid (UA) due to large surface area of Au NPs and ZnO NRs, and thus can be used as electrochemical sensors. Differential pulse voltammetry results showed that AA and UA could be detected simultaneously by ZnO NRs-Au NPs hybrids modified glassy carbon electrode. The linear ranges for AA and UA are 0.1 to 4 mM and 0.01 to 0.4 mM, respectively. The results suggest promising future applications in clinical diagnosis. - Highlights: • ZnO nanorods-Au nanoparticles were synthesized by in-situ plasma sputtering method. • Influence of sputtering time on the formation of Au nanoparticles was studied. • It exhibited a strong electrocatalytic activity toward the oxidation of ascorbic acid and uric acid. • A portable and cheap approach for simultaneous detection of ascorbic acid and uric acid was developed.

Thin Film growth and characterization of Ti doped ZnO by RF/DC magnetron sputtering

KAUST Repository

Baseer Haider, M.

2015-01-01

Thin film Ti doped ZnO (Ti-ZnO) film were grown on sapphire (0001) substrate by RF and DC magnetron sputtering. Films were grown at a substrate temperature of 250 °C with different Ti/Zn concentration. Surface chemical study of the samples was performed by X-ray photoelectron spectroscopy to determine the stoichiometry and Ti/Zn ratio for all samples. Surface morphology of the samples were studied by atomic force microscopy. X-ray diffraction was carried out to determine the crystallinity of the film. No secondary phases of TixOy was observed. We observed a slight increase in the lattice constant with the increase in Ti concentration in ZnO. No ferromagnetic signal was observed for any of the samples. However, some samples showed super-paramagnetic phase. © 2015 Materials Research Society.

Surface characteristics of hydroxyapatite/titanium composite layer on the Ti-35Ta-xZr surface by RF and DC sputtering

International Nuclear Information System (INIS)

Kim, Won-Gi; Choe, Han-Cheol

2011-01-01

The purpose of this study was to investigate the surface characteristics of hydroxyapatite (HA)/titanium (Ti) composite layer on the Ti-35Ta-xZr alloy surface by radio frequency (RF) and direct current (DC) sputtering for dental application. The magnetron sputtered deposition for the HA was performed in the RF mode and for the Ti in the DC mode. Microstructures of the alloys were examined by optical microscopy (OM) and x-ray diffractometer (XRD). Surface characteristics of coated film was investigated by field-emission scanning electron microscope (FE-SEM) equipped with an energy dispersive x-ray spectrometer (EDS), and XRD. Microstructures of the Ti-35Ta-xZr alloys were changed from α'' phase to β phase, and changed from a needle-like structure to an equiaxed structure with increasing Zr content. From the results of polarization behavior in the Ti-35Ta-15Zr alloy, HA/Ti composite layer showed the good corrosion resistance compared to Ti single layer. The results of alternating current (AC) impedance test indicated that the presence of ha coating acted as a stable barrier in increasing the corrosion resistance.

Influence of deposition parameters on the optical and structural properties of TiO/sub 2/ films produced by reactive dc plasmatron sputtering

Energy Technology Data Exchange (ETDEWEB)

Schiller, S; Beister, G; Sieber, W; Schirmer, G; Hacker, E

1981-09-11

We investigated the variations in the structure and optical properties of TiO/sub 2/ films produced by reactive d.c. plasmatron sputtering with the most important deposition parameters. Over a wide range, the phase composition (ratio of rutile to anatase) and the grain size of the TiO/sub 2/ films can be influenced in a controlled manner by variations in the substrate temperature and the oxygen partial pressure. Because of their high refractive index and low light-scattering losses, plasmatron-sputtered TiO/sub 2/ films are of great interest in the field of optical interference coatings, e.g. for dielectric multilayer stacks.

TiOx deposited by magnetron sputtering: a joint modelling and experimental study

Science.gov (United States)

Tonneau, R.; Moskovkin, P.; Pflug, A.; Lucas, S.

2018-05-01

This paper presents a 3D multiscale simulation approach to model magnetron reactive sputter deposition of TiOx⩽2 at various O2 inlets and its validation against experimental results. The simulation first involves the transport of sputtered material in a vacuum chamber by means of a three-dimensional direct simulation Monte Carlo (DSMC) technique. Second, the film growth at different positions on a 3D substrate is simulated using a kinetic Monte Carlo (kMC) method. When simulating the transport of species in the chamber, wall chemistry reactions are taken into account in order to get the proper content of the reactive species in the volume. Angular and energy distributions of particles are extracted from DSMC and used for film growth modelling by kMC. Along with the simulation, experimental deposition of TiOx coatings on silicon samples placed at different positions on a curved sample holder was performed. The experimental results are in agreement with the simulated ones. For a given coater, the plasma phase hysteresis behaviour, film composition and film morphology are predicted. The used methodology can be applied to any coater and any films. This paves the way to the elaboration of a virtual coater allowing a user to predict composition and morphology of films deposited in silico.

Efficient planar n-i-p type heterojunction flexible perovskite solar cells with sputtered TiO2 electron transporting layers.

Science.gov (United States)

Mali, Sawanta S; Hong, Chang Kook; Inamdar, A I; Im, Hyunsik; Shim, Sang Eun

2017-03-02

The development of hybrid organo-lead trihalide perovskite solar cells (PSCs) comprising an electron transporting layer (ETL), a perovskite light absorber and a hole transporting layer (HTL) has received significant attention for their potential in efficient PSCs. However, the preparation of a compact and uniform ETL and the formation of a uniform light absorber layer suffer from a high temperature processing treatment and the formation of unwanted perovskite islands, respectively. A low temperature/room temperature processed ETL is one of the best options for the fabrication of flexible PSCs. In the present work, we report the implementation of a room temperature processed compact TiO 2 ETL and the synthesis of extremely uniform flexible planar PSCs based on methylammonium lead mixed halides MAPb(I 1-x Br x ) 3 (x = 0.1) via RF-magnetron sputtering and a toluene dripping treatment, respectively. The compact TiO 2 ETLs with different thicknesses (30 to 100 nm) were directly deposited on a flexible PET coated ITO substrate by varying the RF-sputtering time and used for the fabrication of flexible PSCs. The photovoltaic properties revealed that flexible PSC performance is strongly dependent on the TiO 2 ETL thickness. The open circuit voltage (V OC ) and fill factor (FF) are directly proportional to the TiO 2 ETL thickness while the 50 nm thick TiO 2 ETL shows the highest current density (J SC ) of 20.77 mA cm -2 . Our controlled results reveal that the room temperature RF-magnetron sputtered 50 nm-thick TiO 2 ETL photoelectrode exhibits a power conversion efficiency (PCE) in excess of 15%. The use of room temperature synthesis of the compact TiO 2 ETL by RF magnetron sputtering results in an enhancement of the device performance for cells prepared on flexible substrates. The champion flexible planar PSC based on this architecture exhibited a promising power conversion efficiency as high as 15.88%, featuring a high FF of 0.69 and V OC of 1.108 V with a negligible

Magnetoresistance and anomalous Hall effect of reactive sputtered polycrystalline Ti1 - XCrxN films

KAUST Repository

Duan, Xiaofei; Mi, Wenbo; Guo, Zaibing; Bai, Haili

2013-01-01

The reactive-sputtered polycrystalline Ti1 - xCrxN films with 0.17 ≤ x ≤ 0.51 are ferromagnetic and at x = 0.47 the Curie temperature TC shows a maximum of ~ 120 K. The films are metallic at 0 ≤ x ≤ 0.47, while the films with x = 0.51 and 0

Reduction of residual gas in a sputtering system by auxiliary sputter of rare-earth metal

International Nuclear Information System (INIS)

Li Dejie

2002-01-01

In film deposition by sputtering, the oxidation and nitrification of the sputtered material lead to degradation of film quality, particularly with respect to metal sulfide films. We propose to use auxiliary sputtering as a method to produce a fresh film of rare-earth metal, usually dysprosium (Dy), that absorbs the active gases in a sputtering system, greatly reducing the background pressure and protecting the film from oxidation and nitrification effectively. The influence of the auxiliary sputtering power consumption, sputtering time, and medium gas pressure on the background pressure in the vacuum chamber is investigated in detail. If the auxiliary sputtering power exceeds 120 W and the sputtering time is more than 4 min, the background pressure is only one fourth of the ultimate pressure pumped by an oil diffusion pump. The absorption activity of the sputtered Dy film continues at least an hour after completion of the auxiliary sputter. Applied to film deposition of Ti and ZnS, this technique has been proven to be effective. For the Ti film, the total content of N and O is reduced from 45% to 20% when the auxiliary sputtering power of Dy is 120 W, and the sputtering time is 20 min. In the case of ZnS, the content of O is reduced from 8% to 2%

The disclosed transformation of pre-sputtered Ti films into nanoparticles via controlled thermal oxidation

Science.gov (United States)

Awad, M. A.; Raaif, M.

2018-05-01

Nanoparticles of TiO2 were successfully prepared from pre-sputtered Ti films using the controlled thermal oxidation. The effect of oxidation temperature on structural, morphological and optical properties in addition to photocatalysis activity of the sputtered films was tested and explained. Analysis of XRD and EDAX elucidated the enhancement in crystallization and oxygen content with the increase of oxidation temperature. SEM depicted the formation of very fine nanoparticles with no specific border on the films oxidized at 550 and 600 °C, whilst crystallites with larger size of approximately from 16 to 23 nm have been observed for the film oxidized at 650 °C. Both optical transmission and refractive index were increased with increasing the oxidation temperature. A red shift in the absorption edge was obtained for the films oxidized at 650 °C compared to that oxidized at 600 °C. The photocatalysis tests demonstrated the priority of 600 °C nanoparticle films to decompose methyl orange (MO) more than 650 °C treated film.

Optical and structural properties of TiO{sub 2}/Ti/Ag/TiO{sub 2} and TiO{sub 2}/ITO/Ag/ITO/TiO{sub 2} metal-dielectric multilayers by RF magnetron sputtering for display application

Energy Technology Data Exchange (ETDEWEB)

Lee, Jang-Hoon; Lee, Seung-Hyu; Hwangbo, Chang-Kwon [Inha University, Incheon (Korea, Republic of); Lee, Kwang-Su [Quantum Photonic Science Research Center, Hanyang University, Seoul (Korea, Republic of)

2004-03-15

Electromagnetic-interference (EMI) shielding and near-infrared (NIR) cutoff filters for plasma display panels, based on fundamental structures (ITO/Ag/ITO), (TiO{sub 2}/Ti/Ag/TiO{sub 2}) and (TiO{sub 2}/ITO/Ag/ITO/TiO{sub 2}), were designed and prepared by RF-magnetron sputtering. The optical, structural and electrical properties of the filters were investigated by using spectrophotometry, Auger electron spectroscopy, X-ray photoelectron spectroscopy, Rutherford backscattering spectroscopy, atomic force microscopy and four-point-probe measurements. The results show that ITO films as the barriers and base layers lead to higher transmittance in the visible spectrum and smoother surface roughness than Ti metal barriers, while maintaining high NIR cutoff characteristics and chemical stability, which may be attributed to the lower absorption in the interfacial layers and better protection of the Ag layers by the ITO layers.

XPS characterization of surface and interfacial structure of sputtered TiNi films on Si substrate

International Nuclear Information System (INIS)

Fu Yongqing; Du Hejun; Zhang, Sam; Huang Weimin

2005-01-01

TiNi films were prepared by co-sputtering TiNi and Ti targets. X-ray photoelectron spectroscopy (XPS) was employed to study surface chemistry of the films and interfacial structure of Si/TiNi system. Exposure of the TiNi film to the ambient atmosphere (23 deg. C and 80% relatively humidity) facilitated quick adsorption of oxygen and carbon on the surface. With time, carbon and oxygen content increased drastically at the surface, while oxygen diffused further into the layer. After a year, carbon content at the surface became as high as 65.57% and Ni dropped below the detection limit of XPS. Depth profiling revealed that significant inter-diffusion occurred between TiNi film and Si substrate with a layer of 90-100 nm. The detailed bond changes of different elements with depth were obtained using XPS and the formation of titanium silicides at the interface were identified

Effect of microstructure on mechanical and tribological properties of TiAlSiN nanocomposite coatings deposited by modulated pulsed power magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Wu, Z.L. [Surface Engineering Laboratory, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China); College of Engineering, Hunan Agricultural University/Southern Regional Collaborative Innovation Center for Grain and Oil Crops in China, Changsha 410128 (China); Li, Y.G.; Wu, B. [Surface Engineering Laboratory, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China); Lei, M.K., E-mail: surfeng@dlut.edu.cn [Surface Engineering Laboratory, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China)

2015-12-31

TiAlSiN nanocomposite coatings were deposited in a closed field unbalanced magnetron sputtering system by reactive sputtering from Ti{sub 0.475}Al{sub 0.475}Si{sub 0.05} targets using modulated pulsed power magnetron sputtering (MPPMS) under a floating substrate bias. The ratio of the nitrogen flow rate to the total gas flow rate (f{sub N{sub 2}}) was varied from 0 to 40%. The application of MPPMS as sputtering sources was aimed at generating a high ionization degree of the sputtered material and a high plasma density by using a pulsed high power approach. When f{sub N{sub 2}} = 0%, an amorphous-like structure Ti{sub 0.479}Al{sub 0.454}Si{sub 0.066} coating was deposited with a hardness of 10 GPa. When nitrogen was added, an optimized nanocomposite structure of nc-TiAlN/a-Si{sub 3}N{sub 4} formed in the TiAlSiN coating deposited at f{sub N{sub 2}} = 10%, in which 5–10 nm TiAlN nanocrystallites were embedded in a 2–3 nm thick amorphous Si{sub 3}N{sub 4} matrix. As the f{sub N{sub 2}} was increased up to 40%, the elementary composition of the coatings remained almost the same, but the grain size of nanocrystallites approached to 10–20 nm and the AlN phase gradually precipitated. A maximum hardness (H) of 33.2 GPa, a hardness to the elastic modulus (E) ratio of 0.081 and an H{sup 3}/E*{sup 2} ratio of 0.19 GPa were found in the coating deposited at f{sub N{sub 2}} = 10%. The friction coefficient of the TiAlSiN coatings was around 0.8–0.9 as sliding against a Si{sub 3}N{sub 4} counterpart under a normal load of 0.5 N. A wear rate of 2.0 × 10{sup −5} mm{sup 3} N{sup −1} m{sup −1} was measured in the TiAlSiN coatings deposited at f{sub N{sub 2}} = 20–40%. As only a low residual stress is found in the TiAlSiN coatings, we consider the complete phase separation is responsible for the enhanced mechanical and tribological properties of the nc-TiAlN/a-Si{sub 3}N{sub 4} nanocomposite coatings. - Highlights: • TiAlSiN nanocomposite coatings were prepared by

A high-sensitivity, fast-response, rapid-recovery p–n heterojunction photodiode based on rutile TiO{sub 2} nanorod array on p-Si(1 1 1)

Energy Technology Data Exchange (ETDEWEB)

Selman, Abbas M., E-mail: alabbasiabbas@yahoo.co.uk [Nano-Optoelectronics Research and Technology Laboratory (N.O.R.), School of Physics, Universiti Sains Malaysia, Penang 11800 (Malaysia); Department of Pharmacology and Toxicology, College of Pharmacy, University of Kufa, Najaf (Iraq); Hassan, Z.; Husham, M.; Ahmed, Naser M. [Nano-Optoelectronics Research and Technology Laboratory (N.O.R.), School of Physics, Universiti Sains Malaysia, Penang 11800 (Malaysia)

2014-06-01

The growth and characterization of a p–n heterojunction photodiode were studied. This photodiode was based on rutile TiO{sub 2} nanorods (NRs) grown on p-type (1 1 1)-oriented silicon substrate seeded with a TiO{sub 2} layer synthesized by radio-frequency (RF) reactive magnetron sputtering. Chemical bath deposition (CBD) was performed to grow rutile TiO{sub 2} NRs on Si substrate. The structural and optical properties of the sample were studied by X-ray diffraction (XRD) and field emission-scanning electron microscopy (FESEM) analyses. Results showed the tetragonal rutile structure of the synthesized TiO{sub 2} NRs. Optical properties were further examined by photoluminescence spectroscopy, and a high-intensity UV peak centered at around 392 nm compared with visible defect peaks centered at 527 and 707 nm was observed. Upon exposure to 395 nm light (2.3 mW/cm) at five-bias voltage, the device showed 2.9 × 10{sup 2} sensitivity. In addition, the internal gain of the photodiode was 3.92, and the photoresponse peak was 106 mA/W. Furthermore, the photocurrent was 3.06 × 10{sup −4} A. The response and the recovery times were calculated to be 10.4 and 11 ms, respectively, upon illumination to a pulse UV light (405 nm, 0.22 mW/cm{sup 2}) at five-bias voltage. All of these results demonstrate that this high-quality photodiode can be a promising candidate as a low-cost UV photodetector for commercially integrated photoelectronic applications.

Sputter Deposited TiOx Thin-Films as Electron Transport Layers in Organic Solar Cells

DEFF Research Database (Denmark)

Mirsafaei, Mina; Bomholt Jensen, Pia; Lakhotiya, Harish

transparency and favorable energy-level alignment with many commonly used electron-acceptor materials. There are several methods available for fabricating compact TiOx thin-films for use in organic solar cells, including sol-gel solution processing, spray pyrolysis and atomic-layer deposition; however...... of around 7%, by incorporating sputter deposited TiOx thin-films as electron-transport and exciton-blocking layers. In the work, we report on the effect of different TiOx deposition temperatures and thicknesses on the organic-solar-cell device performance. Besides optical characterization, AFM and XRD...... analyses are performed to characterize the morphology and crystal structure of the films, and external quantum efficiency measurements are employed to shed further light on the device performance. Our study presents a novel method for implementation of TiOx thin-films as electron-transport layer in organic...

Fine control of the amount of preferential <001> orientation in DC magnetron sputtered nanocrystalline TiO2 films

International Nuclear Information System (INIS)

Stefanov, B; Granqvist, C G; Österlund, L

2014-01-01

Different crystal facets of anatase TiO 2 are known to have different chemical reactivity; in particular the {001} facets which truncates the bi-tetrahedral anatase morphology are reported to be more reactive than the usually dominant {101} facets. Anatase TiO 2 thin films were deposited by reactive DC magnetron sputtering in Ar/O 2 atmosphere and were characterized using Rietveld refined grazing incidence X-ray diffraction, atomic force microscopy and UV/Vis spectroscopy. By varying the partial O2 pressure in the deposition chamber, the degree of orientation of the grains in the film could be systematically varied with preferred <001> orientation changing from random upto 39% as determined by March-Dollase method. The orientation of the films is shown to correlate with their reactivity, as measured by photo-degradation of methylene blue in water solutions. The results have implications for fabrication of purposefully chemically reactive thin TiO 2 films prepared by sputtering methods

Influence of carbon chemical bonding on the tribological behavior of sputtered nanocomposite TiBC/a-C coatings

International Nuclear Information System (INIS)

Abad, M.D.; Sanchez-Lopez, J.C.; Brizuela, M.; Garcia-Luis, A.; Shtansky, D.V.

2010-01-01

The tribological performance of nanocomposite coatings containing Ti-B-C phases and amorphous carbon (a-C) are studied. The coatings are deposited by a sputtering process from a sintered TiB 2 :TiC target and graphite, using pulsed direct current and radio frequency sources. By varying the sputtering power ratio, the amorphous carbon content of the coatings can be tuned, as observed by X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. The crystalline component consists of very disordered crystals with a mixture of TiB 2 /TiC or TiB x C y phases. A slight increase in crystalline order is detected with the incorporation of carbon in the coatings that is attributed to the formation of a ternary TiB x C y phase. An estimation of the carbon present in the form of carbide (TiB x C y or TiC) and amorphous (a-C) is performed using fitting analysis of the C 1s XPS peak. The film hardness (22 to 31 GPa) correlates with the fraction of the TiB x C y phase that exists in the coatings. The tribological properties were measured by a pin-on-disk tribometer in ambient conditions, using 6 mm tungsten carbide balls at 1 N. The friction coefficients and the wear rates show similar behavior, exhibiting an optimum when the fraction of C atoms in the amorphous phase is near 50%. This composition enables significant improvement of the friction coefficients and wear rates (μ ∼ 0.1; k -6 mm 3 /Nm), while maintaining a good value of hardness (24.6 GPa). Establishing the correlation between the lubricant properties and the fraction of a-C is very useful for purposes of tailoring the protective character of these nanocomposite coatings to engineering applications.

A proposed mechanism for investigating the effect of porous silicon buffer layer on TiO{sub 2} nanorods growth

Energy Technology Data Exchange (ETDEWEB)

Rahmani, N. [Department of Physics, Alzahra University, Tehran, 1993893973 (Iran, Islamic Republic of); Dariani, R.S., E-mail: dariani@alzahra.ac.ir [Department of Physics, Alzahra University, Tehran, 1993893973 (Iran, Islamic Republic of); Rajabi, M. [Deparment of Advanced Materials and Renewable Energies, Iranian Research Organization for Science and Technology (IROST), Tehran 3353136846 (Iran, Islamic Republic of)

2016-03-15

Graphical abstract: - Highlights: • TiO{sub 2} nanorods (NRs) are synthesized on silicon and porous silicon (PS) substrates by hydrothermal method. • TiO{sub 2} NRs grown on PS substrates have a better growth compared to those grown on silicon. • Also increasing substrate porosity leads to an increase in density of the NRs. • We proposed a growth mechanism to explain how can control the local surface chemical potential. - Abstract: In this study, we have synthesized TiO{sub 2} nanorods (NRs) on silicon and porous silicon (PS) substrates by hydrothermal method. The PS substrates with different porosities were fabricated by electrochemical anodization on silicon. According to the field emission electron microscopy images, TiO{sub 2} NRs grown on PS substrates have a better growth compared to those grown on silicon. Also increasing substrate porosity leads to an increase in density of the NRs. Atomic force microscopy observation demonstrates that porous layer formation due to etching of silicon surface leads to an increase of its roughness. Results indicate surface roughness evolution with porosity increasing enhances TiO{sub 2} nucleation on substrate and thus increases TiO{sub 2} NRs density. We propose a growth mechanism to explain how we can control the local surface chemical potential and thus the nucleation and alignment of TiO{sub 2} NRs by surface roughness variation. Also, photoluminescence studies show a red-shift in band gap energy of NRs compared to that of common bulk TiO{sub 2}.

Optical and electrical properties of Ti(Cr)O_2:N thin films deposited by magnetron co-sputtering

International Nuclear Information System (INIS)

Kollbek, K.; Szkudlarek, A.; Marzec, M.M.; Lyson-Sypien, B.; Cecot, M.; Bernasik, A.; Radecka, M.; Zakrzewska, K.

2016-01-01

Graphical abstract: - Highlights: • Co-doped well-crystallized stoichiometric Ti(Cr)O_2:N thin films are deposited. • Magnetron sputtering of ceramic TiO_2 target is a new strategy for co-doping. • Bigger contribution from substitutionally incorporated nitrogen is seen in XPS. • Significant red shift of the fundamental absorption edge is obtained. - Abstract: The paper deals with TiO_2-based thin films, doped with Cr and N, obtained by magnetron co-sputtering from titanium dioxide ceramic and chromium targets in Ar + N_2 atmosphere. Co-doped samples of Ti(Cr)O_2:N are investigated from the point of view of morphological, crystallographic, optical, and electrical properties. Characterization techniques such as: X-ray diffraction, XRD, scanning electron microscopy, SEM, atomic force microscopy, AFM, Energy Dispersive X-ray spectroscopy, EDX, X-ray photoelectron spectroscopy, XPS, optical spectrophotometry as well as impedance spectroscopy are applied. XRD reveals TiO_2 and TiO_2:N thin films are well crystallized as opposed to those of TiO_2:Cr and Ti(Cr)O_2:N. XPS spectra confirm that co-doping has been successfully performed with the biggest contribution from the lower binding energy component of N 1s peak at 396 eV. SEM analysis indicates uniform and dense morphology without columnar growth. Comparison between the band gaps indicates a significant shift of the absorption edge towards visible range from 3.69 eV in the case of non-stoichiometric Ti(Cr)O_2_−_x:N to 2.78 eV in the case of stoichiometric Ti(Cr)O_2:N which should be attributed to the incorporation of both dopants at substitutional positions in TiO_2 lattice. Electrical conductivity of stoichiometric Ti(Cr)O_2:N increases in comparison to co-doped nonstoichiometric TiO_2_−_x thin film and reaches almost the same value as that of TiO_2 stoichiometric film.

Effects of Annealing on TiN Thin Film Growth by DC Magnetron Sputtering

Directory of Open Access Journals (Sweden)

Azadeh Jafari

2014-07-01

Full Text Available We have reviewed the deposition of titanium nitride (TiN thin films on stainless steel substrates by a DC magnetron sputtering method and annealing at different annealing temperatures of 500, 600, and 700°C for 120 min in nitrogen/argon atmospheres. Effects of annealing temperatures on the structural and the optical properties of TiN films were investigated using X-ray diffraction (XRD, atomic force microscope (AFM, field emission scanning electron microscopy (FESEM, and UV-VIS spectrophotometer. Our experimental studies reveal that the annealing temperature appreciably affected the structures, crystallite sizes, and reflection of the films. By increasing the annealing temperature to 700°C crystallinity and reflection of the film increase. These results suggest that annealed TiN films can be good candidate for tokamak first wall due to their structural and optical properties.

Structure and composition of Ba{sub 0.5}Sr{sub 0.5}TiO{sub 3} films deposited on (001) MgO substrates and the influence of sputtering pressure

Energy Technology Data Exchange (ETDEWEB)

Twigg, M.E.; Alldredge, L.M.B.; Chang, W.; Podpirka, A.; Kirchoefer, S.W.; Pond, J.M.

2013-12-02

The structure and composition of Ba{sub 0.5}Sr{sub 0.5}TiO{sub 3} thin films, sputter deposited on (001) MgO substrates, have been characterized by transmission electron microscopy. Deviations in film stoichiometry are seen to strongly correlate with the structural and dielectric properties of these films, with the films deposited at the lower sputtering pressures either Ti-deficient or capped with a titanium oxide layer similar to the rutile TiO{sub 2} phase. Preferential sputtering of cations is found to be an important factor governing film stoichiometry. The Ti-deficient films deposited at a lower sputtering pressure contain Ruddlesden–Popper faults that increase the average lattice constant of the film and result in compressive strain and low dielectric tunability. - Highlights: • Ba{sub 0.5}Sr{sub 0.5}TiO{sub 3} (BST) film deposited at very low pressure is capped with TiO{sub 2} layer. • TiO{sub 2} capped film is under only slight compressive strain, but has poor tunability. • BST films deposited at low pressure contain Ruddlesden–Popper Faults (RPFs). • RPF-containing films have high compressive strains and poor dielectric tunability. • High-pressure films have no RPFs, little compression strain, and high tunability.

Syntheses and characterization of TiC/a:C composite coatings using pulsed closed field unbalanced magnetron sputtering (P-CFUBMS)

International Nuclear Information System (INIS)

Lin, J.; Moore, J.J.; Mishra, B.; Pinkas, M.; Sproul, W.D.

2008-01-01

TiC/a:C nanocomposite coatings were prepared by reactively sputtering titanium and graphite targets in pure argon atmosphere using a pulsed closed field unbalanced magnetron sputtering (P-CFUBMS) system. The microstructure of TiC/a:C coatings consisting of nanocrystalline TiC dispersed in an amorphous matrix of free carbon was investigated using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). The effects of coating compositions on the structure and properties of TiC/a:C coatings were investigated. In the present study, TiC/a:C coatings exhibit high hardness (24-29 GPa), low coefficient of friction (0.24-0.25) and low wear rate (less than 2.5 x 10 -7 mm 3 N -1 m -1 ) when the carbon concentration is in the range of 55-66 at.%. Further increase of the carbon content beyond 70 at.% significantly decreased the volume fraction of TiC nanocrystalline and formed a large amount of free amorphous carbon in the coatings. The excessive amorphous carbon phases resulted in a decrease in the coating hardness and the sliding friction coefficient, e.g. a low COF of 0.15 was obtained when the carbon concentration reached 80.5 at.%. However, the decreased hardness will lead to an increase in the wear rate in these high carbon content TiC/a:C coatings

Ultimate pressures achieved in TiZrV sputter-coated vacuum chambers

CERN Document Server

Benvenuti, Cristoforo; Ruzinov, V

2001-01-01

Two metre long, cylindrical vacuum chambers of diameter ranging from 34 to 100 mm, coated with TiZrV getter films by sputtering, have been baked for about 24 h at temperatures from 120 to 250 degrees C. The ultimate pressures achieved after bakeout were found to correspond to the ratio of the pressure gauge degassing to the effective pumping speed provided by the chamber at the location of the gauge. The results covering a pressure range from 10/sup -11/ Torr down to 10 /sup -13/ Torr are presented and discussed. (6 refs).

Ion beam sputter deposited TiAlN films for metal-insulator-metal (Ba,Sr)TiO3 capacitor application

International Nuclear Information System (INIS)

Lee, S.-Y.; Wang, S.-C.; Chen, J.-S.; Huang, J.-L.

2008-01-01

The present study evaluated the feasibility of TiAlN films deposited using the ion beam sputter deposition (IBSD) method for metal-insulator-metal (MIM) (Ba,Sr)TiO 3 (BST) capacitors. The BST films were crystallized at temperatures above 650 deg. C. TiAlN films deposited using the IBSD method were found having smooth surface and low electrical resistivity at high temperature conditions. TiAlN films showed a good diffusion barrier property against BST components. The J-E (current density-electric field) characteristics of Al/BST/TiAlN capacitors were good, with a high break down electric field of ± 2.5 MV/cm and a leakage current density of about 1 x 10 -5 A/cm 2 at an applied field of ± 0.5 MV/cm. Thermal stress and lateral oxidation that occurred at the interface damaged the capacitor stacking structure. Macro holes that dispersed on the films resulted in higher leakage current and inconsistent J-E characteristics. Vacuum annealing with lower heating rate and furnace cooling, and a Ti-Al adhesion layer between TiAlN and the SiO 2 /Si substrate can effectively minimize the stress effect. TiAlN film deposited using IBSD can be considered as a potential electrode and diffusion barrier material for MIM BST capacitors

Ti-Al-Si-C-N hard coatings synthesized by hybrid arc enhanced magnetron sputtering

International Nuclear Information System (INIS)

Wu, Guizhi; Liu, Sitao; Ma, Shengli; Xu, Kewei; Vincent, Ji; Chu, Paul K.

2010-01-01

Ti-Al-Si-C-N coatings are deposited by hybrid arc-enhanced magnetic sputtering and characterized by various micro- and macro-tools. X-ray diffraction, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy reveal that the coatings are nanocomposites consisting of nanocrystallites and amorphous phases. They are generally in the form of nc-(Ti,Al)(C,N)/a-Si_3N_4/a-C depending on the composition of the coatings. With increasing Al concentrations, the X-ray diffraction peaks shift to a lower angle indicating compressive stress in the coatings. The measured hardness also diminishes implying reduced contributions from the self-organized stable nanostructure. The dry friction coefficients of the Ti-Al-Si-C-N coatings are found to be about 0.3 which is lower than that of conventional Ti-Si-N coatings. These coatings can find potential applications requiring high temperature with heavy contact loading. (author)

Dense and high-stability Ti2AlN MAX phase coatings prepared by the combined cathodic arc/sputter technique

Science.gov (United States)

Wang, Zhenyu; Liu, Jingzhou; Wang, Li; Li, Xiaowei; Ke, Peiling; Wang, Aiying

2017-02-01

Ti2AlN belongs to a family of ternary nano-laminate alloys known as the MAX phases, which exhibit a unique combination of metallic and ceramic properties. In the present work, the dense and high-stability Ti2AlN coating has been successfully prepared through the combined cathodic arc/sputter deposition, followed by heat post-treatment. It was found that the as-deposited Ti-Al-N coating behaved a multilayer structure, where (Ti, N)-rich layer and Al-rich layer grew alternately, with a mixed phase constitution of TiN and TiAlx. After annealing at 800 °C under vacuum condition for 1.5 h, although the multilayer structure still was found, part of multilayer interfaces became indistinct and disappeared. In particular, the thickness of the Al-rich layer decreased in contrast to that of as-deposited coating due to the inner diffusion of the Al element. Moreover, the Ti2AlN MAX phase emerged as the major phase in the annealed coatings and its formation mechanism was also discussed in this study. The vacuum thermal analysis indicated that the formed Ti2AlN MAX phase exhibited a high-stability, which was mainly benefited from the large thickness and the dense structure. This advanced technique based on the combined cathodic arc/sputter method could be extended to deposit other MAX phase coatings with tailored high performance like good thermal stability, high corrosion and oxidation resistance etc. for the next protective coating materials.

IBA analysis and corrosion resistance of TiAlPtN/TiAlN/TiAl multilayer films deposited over a CoCrMo using magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Canto, C.E., E-mail: carloscanto2012@yahoo.com.mx [Instituto de Física, Universidad Nacional Autónoma de México, Apartado Postal 20-364, 01000 México D.F. (Mexico); Andrade, E.; Lucio, O. de; Cruz, J.; Solís, C. [Instituto de Física, Universidad Nacional Autónoma de México, Apartado Postal 20-364, 01000 México D.F. (Mexico); Rocha, M.F. [ESIME-Z, IPN, U.P. ALM, Gustavo A. Madero, C.P. 07738 México D.F. (Mexico); Alemón, B. [Departamento de Ingeniería de Proyectos, CUCEI, Universidad de Guadalajara, J. Guadalupe Zuno 48, Los Belenes, Zapopan, Jalisco 45101 (Mexico); Tecnológico de Monterrey, Av. General Ramón Corona 2514, Col. Nuevo México, Zapopan, Jalisco 45201 (Mexico); Flores, M. [Departamento de Ingeniería de Proyectos, CUCEI, Universidad de Guadalajara, J. Guadalupe Zuno 48, Los Belenes, Zapopan, Jalisco 45101 (Mexico); Huegel, J.C. [Tecnológico de Monterrey, Av. General Ramón Corona 2514, Col. Nuevo México, Zapopan, Jalisco 45201 (Mexico)

2016-03-15

The corrosion resistance and the elemental profile of multilayer coatings of TiAlPtN/TiAlN/TiAl synthesized by Physical Vapor Deposition (PVD) reactive magnetron sputtering over a CoCrMo alloy substrate in 10 periods of 30 min each were analyzed and compared to those of the substrate alone and to that of a TiAlPtN single layer coating of the same thickness. The objective of the present work was to create multilayers with different amounts of Pt to enhance the corrosion resistance of a biomedical alloy of CoCrMo. Corrosion tests were performed using Simulated Body Fluid (SBF) using potentiodynamic polarization tests at typical body temperature. The elemental composition and thickness of the coatings were evaluated with the combination of two ion beam analysis (IBA) techniques: a Rutherford Backscattering Spectroscopy (RBS) with alpha beam and a Nuclear Reaction Analysis with a deuteron beam.

IBA analysis and corrosion resistance of TiAlPtN/TiAlN/TiAl multilayer films deposited over a CoCrMo using magnetron sputtering

International Nuclear Information System (INIS)

Canto, C.E.; Andrade, E.; Lucio, O. de; Cruz, J.; Solís, C.; Rocha, M.F.; Alemón, B.; Flores, M.; Huegel, J.C.

2016-01-01

The corrosion resistance and the elemental profile of multilayer coatings of TiAlPtN/TiAlN/TiAl synthesized by Physical Vapor Deposition (PVD) reactive magnetron sputtering over a CoCrMo alloy substrate in 10 periods of 30 min each were analyzed and compared to those of the substrate alone and to that of a TiAlPtN single layer coating of the same thickness. The objective of the present work was to create multilayers with different amounts of Pt to enhance the corrosion resistance of a biomedical alloy of CoCrMo. Corrosion tests were performed using Simulated Body Fluid (SBF) using potentiodynamic polarization tests at typical body temperature. The elemental composition and thickness of the coatings were evaluated with the combination of two ion beam analysis (IBA) techniques: a Rutherford Backscattering Spectroscopy (RBS) with alpha beam and a Nuclear Reaction Analysis with a deuteron beam.

Structural and optical properties of electro-optic material. Sputtered (Ba,Sr)TiO3

International Nuclear Information System (INIS)

Suzuki, Masato; Xu, Zhimou; Tanushi, Yuichiro; Yokoyama, Shin

2006-01-01

In order to develop a novel ring resonator optical switch, we have studied the structural and optical properties of the electro-optic material (Ba,Sr)TiO 3 (BST) deposited by RF sputtering on a SiO 2 cladding layer (1.0 μm). The crystallinity of the BST films is evaluated by X-ray diffraction and the optical propagation loss of the waveguides is measured using a He-Ne laser. As a result, it is found that there is a strong relationship between the optical propagation loss and crystallinity of the sputtered film. It is suggested that the propagating light is influenced by the crystal property, for example, the grain size and density of the polycrystalline BST film. (author)

Composition, morphology and mechanical properties of sputtered TiAlN coating

Energy Technology Data Exchange (ETDEWEB)

Budi, Esmar, E-mail: esmarbudi@unj.ac.id [Department of Physics, Faculty of Science and Mathematics, Universitas Negeri Jakarta, Jl. Pemuda No. 10, Jakarta 13220 (Indonesia); Razali, M. Mohd. [Faculty of Manufacturing Engineering, Universiti Teknikal Malaysia Melaka, Karung Berkunci No. 1752 Pejabat Pos Durian Tunggal 76109 Melaka (Malaysia); Nizam, A. R. Md. [Faculty of Manufacturing Engineering, UniversitiTeknikal Malaysia Melaka, Karung Berkunci No. 1752 Pejabat Pos Durian Tunggal 76109 Melaka (Malaysia)

2014-03-24

TiAlN coating was deposited on the tungsten carbide cutting tool by using DC magnetron sputtering system to study the influence of substrate bias and nitrogen flow rate on the composition, morphology and mechanical properties. The negatively substrate bias and nitrogen flow rate was varied from about −79 to −221 V and 30 sccm to 72 sccm, respectively. The coating composition and roughness were characterized by using SEM/EDX and Atomic Force Microscopy (AFM), respectively. The dynamic ultra micro hardness tester was used to measure the mechanical properties. The coating hardness increases to about 10-12 GPa with an increase of the negatively substrate bias up to − 200 V and it tend to decrease with an increase in nitrogen flow rate up to 70 sccm. The increase of hardness follows the increase of Ti and N content and rms coating roughness.

Optical and electrical properties of Ti(Cr)O{sub 2}:N thin films deposited by magnetron co-sputtering

Energy Technology Data Exchange (ETDEWEB)

Kollbek, K., E-mail: kamila.kollbek@agh.edu.pl [Academic Centre for Materials and Nanotechnology, AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Krakow (Poland); Szkudlarek, A.; Marzec, M.M. [Academic Centre for Materials and Nanotechnology, AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Krakow (Poland); Lyson-Sypien, B.; Cecot, M. [Faculty of Computer Science, Electronics and Telecommunications, AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Krakow (Poland); Bernasik, A. [Academic Centre for Materials and Nanotechnology, AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Krakow (Poland); Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Krakow (Poland); Radecka, M. [Faculty of Materials Science and Ceramics, AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Krakow (Poland); Zakrzewska, K. [Faculty of Computer Science, Electronics and Telecommunications, AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Krakow (Poland)

2016-09-01

Graphical abstract: - Highlights: • Co-doped well-crystallized stoichiometric Ti(Cr)O{sub 2}:N thin films are deposited. • Magnetron sputtering of ceramic TiO{sub 2} target is a new strategy for co-doping. • Bigger contribution from substitutionally incorporated nitrogen is seen in XPS. • Significant red shift of the fundamental absorption edge is obtained. - Abstract: The paper deals with TiO{sub 2}-based thin films, doped with Cr and N, obtained by magnetron co-sputtering from titanium dioxide ceramic and chromium targets in Ar + N{sub 2} atmosphere. Co-doped samples of Ti(Cr)O{sub 2}:N are investigated from the point of view of morphological, crystallographic, optical, and electrical properties. Characterization techniques such as: X-ray diffraction, XRD, scanning electron microscopy, SEM, atomic force microscopy, AFM, Energy Dispersive X-ray spectroscopy, EDX, X-ray photoelectron spectroscopy, XPS, optical spectrophotometry as well as impedance spectroscopy are applied. XRD reveals TiO{sub 2} and TiO{sub 2}:N thin films are well crystallized as opposed to those of TiO{sub 2}:Cr and Ti(Cr)O{sub 2}:N. XPS spectra confirm that co-doping has been successfully performed with the biggest contribution from the lower binding energy component of N 1s peak at 396 eV. SEM analysis indicates uniform and dense morphology without columnar growth. Comparison between the band gaps indicates a significant shift of the absorption edge towards visible range from 3.69 eV in the case of non-stoichiometric Ti(Cr)O{sub 2−x}:N to 2.78 eV in the case of stoichiometric Ti(Cr)O{sub 2}:N which should be attributed to the incorporation of both dopants at substitutional positions in TiO{sub 2} lattice. Electrical conductivity of stoichiometric Ti(Cr)O{sub 2}:N increases in comparison to co-doped nonstoichiometric TiO{sub 2−x} thin film and reaches almost the same value as that of TiO{sub 2} stoichiometric film.

Effect of target power on the physical properties of Ti thin films prepared by DC magnetron sputtering with supported discharge

Directory of Open Access Journals (Sweden)

Kavitha A.

2017-02-01

Full Text Available The present paper describes the effect of target power on the properties of Ti thin films prepared by DC magnetron sputtering with (triode mode and without (diode mode supported discharge. The traditional diode magnetron sputtering with an addition of a hot filament has been used to sustain the discharge at a lower pressure. The effect of target power (60, 80, 100 and 120 W on the physical properties of Ti thin films has been studied in diode and triode modes. XRD studies showed that the Ti thin films prepared at a target power up to 100 W in diode mode were amorphous in nature. The Ti thin films exhibited crystalline structure at much lower target power of 80 W with a preferred orientation along (0 0 2 plane. The grain size of Ti thin films prepared in triode mode increased from 64 nm to 80 nm, whereas in diode mode, the grain size increased from 2 nm to 5 nm. EDAX analysis confirmed that the incorporation of reactive gases was lower in triode mode compared to diode mode. The electrical resistivity of Ti thin films deposited in diode mode was found to be 85 µΩ⋅cm (target power 120 W. The electrical resistivity of Ti thin films in triode mode was found to be deceased to 15.2 µΩ⋅cm (target power 120 W.

Preparation of Pb(Zr, Ti)O3 Thin Films by Plasma-Assisted Sputtering

Science.gov (United States)

Hioki, Tsuyoshi; Akiyama, Masahiko; Ueda, Tomomasa; Onozuka, Yutaka; Suzuki, Kouji

1999-09-01

A novel plasma-assisted RF magnetron sputtering system with an immersed coil antenna between a target and a substrate was applied for preparing Pb(Zr, Ti)O3 (PZT) thin films. The antenna enabled the generation of inductively coupled plasma (ICP) independently of the target RF source. The plasma assisted by the antenna resulted in the changes of ion fluxes and these energy distributions irradiating to the substrate. The crystalline phase of the deposited PZT thin films was occupied by the perovskite phase depending on the antenna power. In addition, a high deposition rate, modified uniformity of film thickness, and a dense film structure with large columnar grains were obtained as a result of effects of the assisted plasma. The application of the plasma-assisted sputtering method may enable the preparation of PZT thin films that haveexcellent properties.

Omnidirectional photonic band gap in magnetron sputtered TiO{sub 2}/SiO{sub 2} one dimensional photonic crystal

Energy Technology Data Exchange (ETDEWEB)

Jena, S., E-mail: shuvendujena9@gmail.com [Atomic & Molecular Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Tokas, R.B.; Sarkar, P. [Atomic & Molecular Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Misal, J.S.; Maidul Haque, S.; Rao, K.D. [Photonics & Nanotechnology Section, BARC-Vizag, Autonagar, Atomic & Molecular Physics Division, Bhabha Atomic Research Centre facility, Visakhapatnam 530 012 (India); Thakur, S.; Sahoo, N.K. [Atomic & Molecular Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)

2016-01-29

One dimensional photonic crystal (1DPC) of TiO{sub 2}/SiO{sub 2} multilayer has been fabricated by sequential asymmetric bipolar pulsed dc magnetron sputtering of TiO{sub 2} and radio frequency magnetron sputtering of SiO{sub 2} to achieve wide omnidirectional photonic band in the visible region. The microstructure and optical response of the TiO{sub 2}/SiO{sub 2} photonic crystal have been characterized by atomic force microscopy, scanning electron microscopy and spectrophotometry respectively. The surface of the photonic crystal is very smooth having surface roughness of 2.6 nm. Reflection and transmission spectra have been measured in the wavelength range 300 to 1000 nm for both transverse electric and transverse magnetic waves. Wide high reflection photonic band gap (∆ λ = 245 nm) in the visible and near infrared regions (592–837 nm) at normal incidence has been achieved. The measured photonic band gap (PBG) is found well matching with the calculated photonic band gap of an infinite 1DPC. The experimentally observed omnidirectional photonic band 592–668 nm (∆ λ = 76 nm) in the visible region with band to mid-band ratio ∆ λ/λ = 12% for reflectivity R > 99% over the incident angle range of 0°–70° is found almost matching with the calculated omnidirectional PBG. The omnidirectional reflection band is found much wider as compared to the values reported in literature so far in the visible region for TiO{sub 2}/SiO{sub 2} periodic photonic crystal. - Highlights: • TiO{sub 2}/SiO{sub 2} 1DPC has been fabricated using magnetron sputtering technique. • Experimental optical response is found good agreement with simulation results. • Wide omnidirectional photonic band in the visible spectrum has been achieved.

Magnetron sputtered TiN thin films toward enhanced performance supercapacitor electrodes

KAUST Repository

Wei, Binbin

2018-04-09

Supercapacitors as a new type of energy storage devices bridging the gap between conventional capacitors and batteries have aroused widespread concern. Herein, binder-free titanium nitride (TiN) thin film electrodes for supercapacitors prepared by reactive magnetron sputtering technology are reported. The effect of N2 content on the supercapacitor performance is evaluated. A highest specific capacitance of 27.3 mF cm−2 at a current density of 1.0 mA cm−2, together with excellent cycling performance (98.2% capacitance retention after 20,000 cycles at 2.0 mA cm−2) is achieved in a 0.5 M H2SO4 aqueous electrolyte. More importantly, a symmetric supercapacitor device assembled on the basis of TiN thin films can deliver a maximum energy density of 17.6 mWh cm−3 at a current density of 0.2 mA cm−2 and a maximum power density of 10.8 W cm−3 at a current density of 2 mA cm−2 with remarkable cycling stability. As a consequence, TiN thin films demonstrate great potential as promising supercapacitor electrode materials.

Magnetron sputtered TiN thin films toward enhanced performance supercapacitor electrodes

KAUST Repository

Wei, Binbin; Liang, Hanfeng; Zhang, Dongfang; Qi, Zhengbing; Shen, Hao; Wang, Zhoucheng

2018-01-01

Supercapacitors as a new type of energy storage devices bridging the gap between conventional capacitors and batteries have aroused widespread concern. Herein, binder-free titanium nitride (TiN) thin film electrodes for supercapacitors prepared by reactive magnetron sputtering technology are reported. The effect of N2 content on the supercapacitor performance is evaluated. A highest specific capacitance of 27.3 mF cm−2 at a current density of 1.0 mA cm−2, together with excellent cycling performance (98.2% capacitance retention after 20,000 cycles at 2.0 mA cm−2) is achieved in a 0.5 M H2SO4 aqueous electrolyte. More importantly, a symmetric supercapacitor device assembled on the basis of TiN thin films can deliver a maximum energy density of 17.6 mWh cm−3 at a current density of 0.2 mA cm−2 and a maximum power density of 10.8 W cm−3 at a current density of 2 mA cm−2 with remarkable cycling stability. As a consequence, TiN thin films demonstrate great potential as promising supercapacitor electrode materials.

Ion beam sputter deposited TiAlN films for metal-insulator-metal (Ba,Sr)TiO{sub 3} capacitor application

Energy Technology Data Exchange (ETDEWEB)

Lee, S.-Y. [Department of Materials Science and Engineering, National Cheng Kung University, No. 1, Ta-Hsueh Road, Tainan, Taiwan (China); Wang, S.-C. [Department of Mechanical Engineering, Southern Taiwan University of Technology, No. 1, Nantai St, Yung-Kang City, Tainan, Taiwan (China); Chen, J.-S. [Department of Materials Science and Engineering, National Cheng Kung University, No. 1, Ta-Hsueh Road, Tainan, Taiwan (China); Huang, J.-L. [Department of Materials Science and Engineering, National Cheng Kung University, No. 1, Ta-Hsueh Road, Tainan, Taiwan (China)], E-mail: jlh888@mail.ncku.edu.tw

2008-09-01

The present study evaluated the feasibility of TiAlN films deposited using the ion beam sputter deposition (IBSD) method for metal-insulator-metal (MIM) (Ba,Sr)TiO{sub 3} (BST) capacitors. The BST films were crystallized at temperatures above 650 deg. C. TiAlN films deposited using the IBSD method were found having smooth surface and low electrical resistivity at high temperature conditions. TiAlN films showed a good diffusion barrier property against BST components. The J-E (current density-electric field) characteristics of Al/BST/TiAlN capacitors were good, with a high break down electric field of {+-} 2.5 MV/cm and a leakage current density of about 1 x 10{sup -5} A/cm{sup 2} at an applied field of {+-} 0.5 MV/cm. Thermal stress and lateral oxidation that occurred at the interface damaged the capacitor stacking structure. Macro holes that dispersed on the films resulted in higher leakage current and inconsistent J-E characteristics. Vacuum annealing with lower heating rate and furnace cooling, and a Ti-Al adhesion layer between TiAlN and the SiO{sub 2}/Si substrate can effectively minimize the stress effect. TiAlN film deposited using IBSD can be considered as a potential electrode and diffusion barrier material for MIM BST capacitors.

Abnormal electrical resistivity in γ-TiAl thin films deposited by magnetron sputtering

International Nuclear Information System (INIS)

Alford, T.L.; Gadre, K.S.; Kim, H.C.; Deevi, S.C.

2003-01-01

Thin films of γ-TiAl are being considered as a potential conductor and/or diffusion barrier for high temperature electronics because of their high melting points and high oxidation resistance. However, it is not possible to form pure γ-TiAl thin films by thermal annealing of Al/Ti bilayers. This study, however, demonstrates the formation of γ-TiAl thin films by dc magnetron sputtering of a compound target. X-ray diffractometry and Rutherford backscattering spectrometry analyses confirm the γ-TiAl phase formation, composition, and thermal stability in vacuum (up to 700 deg. C, 1 h) on SiO 2 . Four-point probe resistivity measurements in vacuum show an initial increase in the resistivity with temperature up to transition temperature for the γ-TiAl thin films. At higher temperatures a decrease in resistivity with additional heating (i.e., negative temperature coefficient of resistivity, TCR) is seen. The values of dρ/dT are typically on the order of -0.32 μΩ cm/ deg. C between 200 and 550 deg. C. At the highest temperature, a minimum value of resistivity of ∼13 μΩ cm is obtained; this value is about one half the value of bulk TiAl at room temperatures. The negative TCR, low resistivity values at high temperatures, and temperature stability are not typically seen in bulk TiAl. This abnormal electrical property is explained using a modified model for a thermally activated polaron-hopping mechanism

Nanostructured multilayers of TiN/ZrN obtained by magnetron sputtering

International Nuclear Information System (INIS)

Caicedo A, J.C.; Bejarano G, G.; Gomez, M.E.; Prieto, P.; Cortez, C.; Munoz, J.

2007-01-01

In order to find an industrial application for thin films of TiN and ZrN monolayers, as well as TiN/ZrN multilayers were deposited onto silicon (100) and AISI 5160 steel substrates by r.f. (13.56 MHz) multi-target magnetron sputtering from high-purity (99.5%) Ti and (99.5%) Zr targets in an Ar (93%)/N 2 (7%) gas mixture. For their deposition, we applied a substrate bias voltage of -100 V and a target power of 350 W. The films were deposited at a pressure of 6x10 -3 mbar and a temperature of 250 C. The structure, composition, morphology, and topography were characterized by, XRD, FTIR, SEM, AFM, and optical microscopy. Mechanical properties like hardness and elastic modulus were determined by Nanoindentation. Hardness and elastic modulus of the films increased proportionally to the number of bilayers. Finally, cutting tools were coated with 1, 2, 3, 4, 5, 6, 7, and 8 bilayers of TiN/ZrN. Cutting tests on paper blades were conducted. Increased cut quality performance was observed for cutting tools coated with 8 bilayers, as compared to uncoated tools. This work opens the possibility to use coated AISI 5160 as cutting tools for the paper industry, reducing the import of expensive high-quality tool steel. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Nanostructured multilayers of TiN/ZrN obtained by magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Caicedo A., J.C. [CDT ASTIN, SENA Regional Valle, Cali (Colombia); Grupo de Peliculas Delgadas, Universidad del Valle (Colombia); Centro de Excelencia en Nuevos Materiales, CENM, Universidad del Valle (Colombia); Bejarano G., G. [CDT ASTIN, SENA Regional Valle, Cali (Colombia); Group of Corrosion and Protection, Antioquia University, Medellin (Colombia); Gomez, M.E. [Grupo de Peliculas Delgadas, Universidad del Valle (Colombia); Centro de Excelencia en Nuevos Materiales, CENM, Universidad del Valle (Colombia); Prieto, P. [Centro de Excelencia en Nuevos Materiales, CENM, Universidad del Valle (Colombia); Cortez, C.; Munoz, J. [Centro de Investigacion y Estudios Avanzados del CINVESTAV-IPN, Queretaro (Mexico)

2007-07-01

In order to find an industrial application for thin films of TiN and ZrN monolayers, as well as TiN/ZrN multilayers were deposited onto silicon (100) and AISI 5160 steel substrates by r.f. (13.56 MHz) multi-target magnetron sputtering from high-purity (99.5%) Ti and (99.5%) Zr targets in an Ar (93%)/N{sub 2} (7%) gas mixture. For their deposition, we applied a substrate bias voltage of -100 V and a target power of 350 W. The films were deposited at a pressure of 6x10{sup -3} mbar and a temperature of 250 C. The structure, composition, morphology, and topography were characterized by, XRD, FTIR, SEM, AFM, and optical microscopy. Mechanical properties like hardness and elastic modulus were determined by Nanoindentation. Hardness and elastic modulus of the films increased proportionally to the number of bilayers. Finally, cutting tools were coated with 1, 2, 3, 4, 5, 6, 7, and 8 bilayers of TiN/ZrN. Cutting tests on paper blades were conducted. Increased cut quality performance was observed for cutting tools coated with 8 bilayers, as compared to uncoated tools. This work opens the possibility to use coated AISI 5160 as cutting tools for the paper industry, reducing the import of expensive high-quality tool steel. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Properties of TiO{sub 2} thin films deposited by rf reactive magnetron sputtering on biased substrates

Energy Technology Data Exchange (ETDEWEB)

Nezar, Sawsen, E-mail: snezar@cdta.dz [Equipe Plasma & Applications, Division des Milieux Ionisés et Lasers, Centre de Développement des Technologies Avancées, Cité du 20 Aout 1956, Baba Hassen, Alger (Algeria); Laboratoire des phénomènes de transfert, génie chimique, Faculté de Génie des procèdes, USTHB, BP 32 El-alia, Bab Ezzouar, Alger (Algeria); Saoula, Nadia [Equipe Plasma & Applications, Division des Milieux Ionisés et Lasers, Centre de Développement des Technologies Avancées, Cité du 20 Aout 1956, Baba Hassen, Alger (Algeria); Sali, Samira [Centre de Recherche en Technologie des Semi-conducteurs pour l’Energétique (CRTSE Algiers) (Algeria); Faiz, Mohammed; Mekki, Mogtaba [Physics Department, King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia); Laoufi, Nadia Aïcha [Laboratoire des phénomènes de transfert, génie chimique, Faculté de Génie des procèdes, USTHB, BP 32 El-alia, Bab Ezzouar, Alger (Algeria); Tabet, Nouar [Qatar Environment and Energy Research Institute, Hamad Bin Khalifa University (HBKU), Doha (Qatar)

2017-02-15

Highlights: • TiO{sub 2} thin films were deposited on negatively biased substrates by rf magnetron sputtering technique. • The bias favors the formation of TiO{sub 2} crystalline phase. • The roughness of the films increases and the grain size decreases as the bias voltage is varied between (0 and −100 V). • XPS reveals the presence of adsorbed humidity of the surface and Ti{sup 4+} oxidation state in the as prepared samples. - Abstract: TiO{sub 2} thin films are of paramount importance due to their pervasive applications. In contrast to previous published works where the substrate was heated at high temperatures to obtain TiO{sub 2} crystalline phase, we show in this study that it is possible to deposit crystalline TiO{sub 2} thin films on biased and unbiased substrate at room temperature using reactive rf magnetron sputtering. The bias voltage was varied from 0 V to −100 V. The deposited films were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV–vis spectroscopy, Raman spectroscopy, X-ray Photoelectron Spectroscopy (XPS) and atomic force microscopy (AFM). The average crystallite size was estimated using x-ray diffraction. The results showed that the application of negative bias affects the surface roughness of the films and favors the formation of the rutile phase. The root mean square roughness (R{sub rms}), the average grain size and the optical band gap of the films decreased as the substrate bias voltage was varied from 0 to −100 V. The UV–visible transmittance spectra showed that the films were transparent in the visible range and absorb strongly in the UV range. This study shows that biasing the substrate could be a promising and effective alternative to deposit TiO{sub 2} crystallized thin films of engineered properties at room temperature.

Electrical properties of resistive switches based on Ba1-χSrχTiO3 thin films prepared by RF co-sputtering

International Nuclear Information System (INIS)

Marquez H, A.; Hernandez R, E.; Zapata T, M.; Guillen R, J.; Cruz, M. P.; Calzadilla A, O.; Melendez L, M.

2010-01-01

In this work, was proposed the use of Ba 1-χ Sr χ TiO 3 (0≤x≤1) thin films for the construction of metal-insulator-metal heterostructures; and their great potential for the development of non-volatile resistance memories (ReRAM) is shown. The deposition of Ba 1-χ Sr χ TiO 3 thin films was done by the RF co-sputtering technique using two magnetron sputtering cathodes with BaTiO 3 and SrTiO 3 targets. The chemical composition (x parameter) in the deposited Ba 1-χ Sr χ TiO 3 thin films was varied through the RF powder applied to the targets. The constructed metal-insulator-metal heterostructures were Al/Ba 1-χ Sr χ TiO 3 /nichrome. The I-V measurements of the heterostructures showed that their hysteretic characteristics change depending on the Ba/Sr ratio of the Ba 1-χ Sr χ TiO 3 thin films; the Ba/Sr ratio was determined by employing the energy dispersive spectroscopy; Sem micrographs showed that Ba 1-χ Sr χ TiO 3 thin films were uniform without cracks or pinholes. Additionally, the analysis of the X-ray diffraction results indicated the substitutional incorporation of Sr into the BaTiO 3 lattice and the obtainment of crystalline films for the entire range of the x values. (Author)

Effect of plastic strain on shape memory characteristics in sputter-deposited Ti-Ni thin films

International Nuclear Information System (INIS)

Nomura, K.

1995-01-01

The plastic strain which is introduced during cooling and heating under a constant stress has an influence upon the transformation and deformation characteristics of sputter-deposited Ti-Ni shape memory alloy thin films. With increasing the accumulated plastic strain, Ms rises and recovery strain increases. The changes in such characteristics are due to the internal stress field that is formed by plastic deformation. However, the change in Ms in Ti-50.5at%Ni is larger than that in Ti-48.9at%Ni, although the plastic strain in the former is lower than that in the latter. In order to understand this point, the effective internal stresses were estimated in both alloys; the internal stress in the former is more effectively created by the introduction of plastic strain than in the latter. (orig.)

Growing LaAlO3/SrTiO3 interfaces by sputter deposition

Directory of Open Access Journals (Sweden)

I. M. Dildar

2015-06-01

Full Text Available Sputter deposition of oxide materials in a high-pressure oxygen atmosphere is a well-known technique to produce thin films of perovskite oxides in particular. Also interfaces can be fabricated, which we demonstrated recently by growing LaAlO3 on SrTiO3 substrates and showing that the interface showed the same high degree of epitaxy and atomic order as is made by pulsed laser deposition. However, the high pressure sputtering of oxides is not trivial and number of parameters are needed to be optimized for epitaxial growth. Here we elaborate on the earlier work to show that only a relatively small parameter window exists with respect to oxygen pressure, growth temperature, radiofrequency power supply and target to substrate distance. In particular the sensitivity to oxygen pressure makes it more difficult to vary the oxygen stoichiometry at the interface, yielding it insulating rather than conducting.

Modelling of low energy ion sputtering from oxide surfaces

International Nuclear Information System (INIS)

Kubart, T; Nyberg, T; Berg, S

2010-01-01

The main aim of this work is to present a way to estimate the values of surface binding energy for oxides. This is done by fitting results from the binary collisions approximation code Tridyn with data from the reactive sputtering processing curves, as well as the elemental composition obtained from x-ray photoelectron spectroscopy (XPS). Oxide targets of Al, Ti, V, Nb and Ta are studied. The obtained surface binding energies are then used to predict the partial sputtering yields. Anomalously high sputtering yield is observed for the TiO 2 target. This is attributed to the high sputtering yield of Ti lower oxides. Such an effect is not observed for the other studied metals. XPS measurement of the oxide targets confirms the formation of suboxides during ion bombardment as well as an oxygen deficient surface in the steady state. These effects are confirmed from the processing curves from the oxide targets showing an elevated sputtering rate in pure argon.

Investigation of DC magnetron-sputtered TiO2 coatings: Effect of coating thickness, structure, and morphology on photocatalytic activity

DEFF Research Database (Denmark)

Daviðsdóttir, Svava; Shabadi, Rajashekhara; Galca, Aurelian Catalin

2014-01-01

The photocatalytic performance of magnetron-sputtered titanium dioxide (TiO2) coatings of different thickness in anatase crystalline structure deposited on aluminium 1050 alloy substrates was investigated using a combination of photo-electrochemistry, methylene blue decomposition, and microscopic...

Morphological analysis of TiB2 thin film prepared by rf magnetron sputtering

International Nuclear Information System (INIS)

Dai Wei; Zhang Tongjun; Yang Junyou; Sun Rongxing; Xu Juliang

2008-01-01

Superhard TiB 2 thin films were deposited on steel substrates using the radio-frequency magnetron-sputtering technique with a low normalized substrate temperature (0.1 s /T m 2 thin films were overstoichiometric and that the diffusion of Ti and B atoms on the substrate surface was greatly improved at a temperature of 350 deg. C. Moreover, a new dense structure, named the ''equiaxed'' grain structure, was observed by FESEM at this substrate temperature. GIXRD was carried out at different directions with same the grazing-incidence method and the variation of diffraction intensity of the nonrandom textured grains was confirmed. Combined with FESEM and AES analysis, it is suggested that the equiaxed grain structure was located in zone 2 at the normalized substrate temperature as low as 0.18

Chromium doped TiO2 sputtered thin films synthesis, physical investigations and applications

CERN Document Server

Hajjaji, Anouar; Gaidi, Mounir; Bessais, Brahim; El Khakani, My Ali

2014-01-01

This book presents co-sputtered processes ways to produce chrome doped TiO2 thin films onto various substrates such as quartz, silicon and porous silicon. Emphasis is given on the link between the experimental preparation and physical characterization in terms of Cr content. Moreover, the structural, optical and optoelectronic investigations are emphasized throughout. The book explores the potencial applications of devices based on Cr doped TiO2 thin films as gas sensors and in photocatalysis and in the photovoltaic industry. Also, this book provides extensive leads into research literature, and each chapter contains details which aim to develop awareness of the subject and the methods used. The content presented here will be useful for graduate students as well as researchers in materials science, physics, chemistry and engineering.

TiO2 Nanorod Arrays Based Self-Powered UV Photodetector: Heterojunction with NiO Nanoflakes and Enhanced UV Photoresponse.

Science.gov (United States)

Gao, Yanyan; Xu, Jianping; Shi, Shaobo; Dong, Hong; Cheng, Yahui; Wei, Chengtai; Zhang, Xiaosong; Yin, Shougen; Li, Lan

2018-04-04

The self-powered ultraviolet photodetectors (UV PDs) have attracted increasing attention due to their potential applications without consuming any external power. It is important to obtain the high-performance self-powered UV PDs by a simple method for the practical application. Herein, TiO 2 nanorod arrays (NRs) were synthesized by hydrothermal method, which were integrated with p-type NiO nanoflakes to realize a high performance pn heterojunction for the efficient UV photodetection. TiO x thin film can improve the morphological and carrier transport properties of TiO 2 NRs and decrease the surface and defect states, resulting in the enhanced photocurrent of the devices. NiO/TiO 2 nanostructural heterojunctions show excellent rectifying characteristics (rectification ratio of 2.52 × 10 4 and 1.45 × 10 5 for NiO/TiO 2 NRs and NiO/TiO 2 NRs/TiO x , respectively) with a very low reverse saturation current. The PDs based on the heterojunctions exhibit good spectral selectivity, high photoresponsivity, and fast response and recovery speeds without external applied bias under the weak light radiation. The devices demonstrate good stability and repeatability under UV light radiation. The self-powered performance could be attributed to the proper built-in electric field of the heterojunction. TiO 2 NRs and NiO nanoflakes construct the well-aligned energy-band structure. The enhanced responsivity and detectivity for the devices with TiO x thin films is related to the increased interfacial charge separation efficiency, reduced carrier recombination, and relatively good electron transport of TiO 2 NRs.

Atom beam sputtered Ag-TiO{sub 2} plasmonic nanocomposite thin films for photocatalytic applications

Energy Technology Data Exchange (ETDEWEB)

Singh, Jaspal; Sahu, Kavita [School of Basic and Applied Sciences, Guru Gobind Singh Indraprastha University, Dwarka, NewDelhi 110078 (India); Pandey, A. [Solid State Physics Laboratory, Defence Research and Development Organization, Timarpur, Delhi 110054 (India); Kumar, Mohit [Institute of Physics, Sachivalaya Marg, Bhubaneswar, Odisha 751005 (India); Ghosh, Tapas; Satpati, B. [Saha Institute of Nuclear Physics, HBNI, 1/AF, Bidhannagar, Kolkata 700064 (India); Som, T.; Varma, S. [Institute of Physics, Sachivalaya Marg, Bhubaneswar, Odisha 751005 (India); Avasthi, D.K. [Amity Institute of Nanotechnology, Noida 201313, Uttar Pradesh (India); Mohapatra, Satyabrata, E-mail: smiuac@gmail.com [School of Basic and Applied Sciences, Guru Gobind Singh Indraprastha University, Dwarka, NewDelhi 110078 (India)

2017-07-31

The development of nanocomposite coatings with highly enhanced photocatalytic activity is important for photocatalytic purification of water and air. We report on the synthesis of Ag-TiO{sub 2} nanocomposite thin films with highly enhanced photocatalytic activity by atom beam co-sputtering technique. The effects of Ag concentration on the structural, morphological, optical, plasmonic and photocatalytic properties of the nanocomposite thin films were investigated. UV–visible DRS studies revealed the presence of surface plasmon resonance (SPR) peak characteristic of Ag nanoparticles together with the excitonic absorption peak originating from TiO{sub 2} nanoparticles in the nanocomposites. XRD studies showed that the nanocomposite thin films consist of Ag nanoparticles and rutile TiO{sub 2} nanoparticles. The synthesized Ag-TiO{sub 2} nanocomposite thin films with 5 at% Ag were found to exhibit highly enhanced photocatalytic activity for sun light driven photocatalytic degradation of methylene blue in water, indicating their potential application in water purification.

Properties of Sn-doped TiO2 nanotubes fabricated by anodization of co-sputtered Ti–Sn thin films

International Nuclear Information System (INIS)

Kyeremateng, Nana Amponsah; Hornebecq, Virginie; Knauth, Philippe; Djenizian, Thierry

2012-01-01

Self-organized Sn-doped TiO 2 nanotubes (nts) were fabricated for the first time, by anodization of co-sputtered Ti and Sn thin films. This nanostructured material was characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, UV–vis spectroscopy and transmission electron microscopy. Due to their remarkable properties, Sn-doped TiO 2 nts can find potential applications in Li-ion microbatteries, photovoltaics, and catalysis. Particularly, the electrochemical performance as an anode material for Li-ion microbatteries was evaluated in Li test cells. With current density of 70 μA cm −2 (1 C) and cut-off potential of 1 V, Sn-doped TiO 2 nts showed improved performance compared to simple TiO 2 nts, and differential capacity plots revealed that the material undergoes full electrochemical reaction as a Rutile-type TiO 2 .

Venting temperature determines surface chemistry of magnetron sputtered TiN films

Energy Technology Data Exchange (ETDEWEB)

Greczynski, G. [Thin Film Physics Division, Department of Physics (IFM), Linköping University, SE-581 83 Linköping (Sweden); Materials Chemistry, RWTH Aachen University, Kopernikusstr. 10, D-52074 Aachen (Germany); Mráz, S.; Schneider, J. M. [Materials Chemistry, RWTH Aachen University, Kopernikusstr. 10, D-52074 Aachen (Germany); Hultman, L. [Thin Film Physics Division, Department of Physics (IFM), Linköping University, SE-581 83 Linköping (Sweden)

2016-01-25

Surface properties of refractory ceramic transition metal nitride thin films grown by magnetron sputtering are essential for resistance towards oxidation necessary in all modern applications. Here, typically neglected factors, including exposure to residual process gases following the growth and the venting temperature T{sub v}, each affecting the surface chemistry, are addressed. It is demonstrated for the TiN model materials system that T{sub v} has a substantial effect on the composition and thickness-evolution of the reacted surface layer and should therefore be reported. The phenomena are also shown to have impact on the reliable surface characterization by x-ray photoelectron spectroscopy.

Chemical and microstructural characterization of rf-sputtered BaTiO{sub 3} nano-capacitors with Ni electrodes

Energy Technology Data Exchange (ETDEWEB)

Reck, James N., E-mail: j.n.reck@gmail.com [Missouri University of Science and Technology, Department of Materials Science and Engineering, Rolla, MO 65409 (United States); Cortez, Rebecca [Union College, Department of Mechanical Engineering, Schenectady, NY 12308 (United States); Xie, S. [Northwestern University, Department of Materials Science and Engineering, Evanston, IL 60208 (United States); Zhang Ming; O' Keefe, Matthew; Dogan, Fatih [Missouri University of Science and Technology, Department of Materials Science and Engineering, Rolla, MO 65409 (United States)

2012-05-15

Chemical and microstructural evaluation techniques have been used to characterize sputter deposited 100-150 nm thick BaTiO{sub 3} nano-capacitors with 30 nm thick Ni electrodes fabricated on Si/SiO{sub 2} wafers. More than 99% of devices had resistance > 20 M{Omega}. Electrodes were found to have a roughness, R{sub a}, of about 0.66 {+-} 0.04 nm, and the BaTiO{sub 3} had a R{sub a} value of 1.3 {+-} 0.12 nm. Characterization of the BaTiO{sub 3} film chemistry with X-ray Photoelectron Spectroscopy (XPS) showed the films had excess oxygen and Ba:Ti ratios ranging from 0.78 to 1.1, depending on sputtering conditions. X-ray diffraction showed a broad peak between approximately 20 Degree-Sign and 35 Degree-Sign 2{theta}, indicating the films were either amorphous or contained grain sizes less than 5 nm. Focused ion beam images confirmed the presence of smooth, conformal films, with no visible signs of macro-defects such as pin-holes, cracks, or pores. High resolution transmission electron microscopy (TEM) and electron diffraction patterns confirmed the presence of a nearly amorphous film with limited short range order. No correlation was found between the chemical and microstructural studies with the dielectric permittivity (280-1000), loss (0.02-0.09), and/or resistivity (8.7 Multiplication-Sign 10{sup 10}-1.5 Multiplication-Sign 10{sup 12} {Omega} cm) values.

Properties of RF-Sputtered PZT Thin Films with Ti/Pt Electrodes

Directory of Open Access Journals (Sweden)

Cui Yan

2014-01-01

Full Text Available Effect of annealing temperature and thin film thickness on properties of Pb(Zr0.53Ti0.47O3 (PZT thin film deposited via radiofrequency magnetron sputtering technique onto Pt/Ti/SiO2/Si substrate was investigated. Average grain sizes of the PZT thin film were measured by atomic force microscope; their preferred orientation was studied through X-ray diffraction analysis. Average residual stress in the thin film was estimated according to the optimized Stoney formula, and impedance spectroscopy characterization was performed via an intelligent LCR measuring instrument. Average grain sizes of PZT thin films were 60 nm~90 nm and their average roughness was less than 2 nm. According to X-ray diffraction analysis, 600°C is the optimal annealing temperature to obtain the PZT thin film with better crystallization. Average residual stress showed that thermal mismatch was the decisive factor of residual stress in Pt/Ti/SiO2/Si substrate; the residual stress in PZT thin film decreased as their thickness increased and increased with annealing temperature. The dielectric constant and loss angle tangent were extremely increased with the thickness of PZT thin films. The capacitance of the device can be adjusted according to the thickness of PZT thin films.

Incorporation of N in TiO{sub 2} films grown by DC-reactive magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Serio, S. [CEFITEC, Departamento de Fisica, Faculdade de Ciencias e Tecnologia da Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Melo Jorge, M.E. [CCMM, Departamento de Quimica e Bioquimica, Faculdade de Ciencias da Universidade de Lisboa, Campo Grande C8, 1749-016 Lisboa (Portugal); Nunes, Y. [CEFITEC, Departamento de Fisica, Faculdade de Ciencias e Tecnologia da Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Barradas, N.P. [Instituto Tecnologico e Nuclear and CFNUL, E.N. 10, Sacavem 2686-953 (Portugal); Alves, E., E-mail: ealves@itn.pt [Instituto Tecnologico e Nuclear and CFNUL, E.N. 10, Sacavem 2686-953 (Portugal); Munnik, F. [Helmholtz-Zentrum Dresden-Rossendorf (Germany)

2012-02-15

Photocatalytic properties of TiO{sub 2} are expected to play an important role on emerging technologies based on OH radicals to destroy harmful nonbiodegradable organic and inorganic contaminants in water. The drawback is the wide band gap of TiO{sub 2} (3.2 eV) limiting its use to the UV part of electromagnetic spectrum under sunlight. Therefore, modifications of TiO{sub 2} are needed to tune the gap in order to allow an efficient use of the entire solar spectrum. One possibility is N-doping of TiO{sub 2} to make the photocatalytic activity possible under visible light and more suitable for water treatment. In our study nitrogen-doped TiO{sub 2} (TiO{sub 2-x}N{sub x}) films were deposited by DC-reactive magnetron sputtering using a dual-magnetron co-deposition apparatus on unheated glass and silicon substrates using a pure titanium target. The depth profile of nitrogen was measured with heavy ion elastic recoil detection analysis combined with Rutherford backscattering spectrometry (RBS) and correlated with the optical and structural properties obtained by UV-VIS spectroscopy and X-ray diffraction (XRD).

(Ba+Sr)/Ti ratio dependence of the dielectric properties for (Ba0.5Sr0.5)TiO3 thin films prepared by ion beam sputtering

Science.gov (United States)

Yamamichi, Shintaro; Yabuta, Hisato; Sakuma, Toshiyuki; Miyasaka, Yoichi

1994-03-01

(Ba0.5Sr0.5)TiO3 thin films were prepared by ion beam sputtering from powder targets with (Ba+Sr)/Ti ratios ranging from 0.80 to 1.50. All of the perovskite (Ba,Sr)TiO3 films were single phase except for the film with a (Ba+Sr)/Ti ratio of 1.41. The dielectric constant values notably depended on the (Ba+Sr)/Ti ratio for films thicker than 70 nm. The highest dielectric constant of 580 was achieved for the 5% (Ba+Sr) rich film. This (Ba+Sr)/Ti ratio dependence was diminished by the thickness dependence for thinner films. The grain sizes for the 9% (Ba+Sr) rich film and for the 6% (Ba+Sr) poor film ranged from 70 to 100 nm and from 30 to 60 nm, respectively. This grain size difference could explain why slightly A-site rich (Ba,Sr)TiO3 films have a larger dielectric constant than A-site poor films.

Growth of TiO2 Thin Film on Various Substrates using RF Magnetron Sputtering

International Nuclear Information System (INIS)

Ali, Riyaz Ahmad Mohamed; Nayan, Nafarizal

2011-01-01

The conductivity of Titanium Dioxide (TiO 2 ) thin film fabricated using Radio Frequency (RF) Magnetron Sputtering on Silicon (Si), Indium doped--Tin Oxide (ITO) and microscope glass (M) substrates is presented in this paper. The dependant of thin film thickness and type of substrate been discussed. TiO 2 was deposited using Ti target in Ar+O 2 (45:10) mixture at 250 W for 45, 60, 75, 90, 105 and 120 minute. Resultant thickness varies from 295 nm to 724 nm with deposition rate 6.4 nm/min. On the other hand, resistivity, Rs value for ITO substrate is between 5.72x10 -7 to 1.54x10 -6 Ω.m, Si substrate range is between 3.52x10 -6 to 1.76x10 -5 Ω.m and M substrate range is between 99 to 332 Ω.m. The value of resistivity increases with the thickness of the thin film.

Photocatalytic Activity of TiO2 Thin Films Obtained by the Sputtering RF in Wastewater

Science.gov (United States)

Cardona Bedoya, Jairo Armando; Sanchez Velandia, Wilmer Asmed; Delgado Rosero, Miguel Iban; Florido Cuellar, Alex Enrique; Zelaya Angel, Orlando; Mendoza Alvarez, Julio G.

2011-03-01

The photocatalytic activity of Ti O2 thin films in wastewater, under an UV irradiation, is studied. The films were prepared on corning glass substrates by the sputtering RF technique. We present evidence on the photocatalytic degradation, carried out by advanced oxidation processes (AOPs) in domestic wastewater pretreated with UASB (upflow anaerobic sludge blanket) reactors. Ti O2 films were illuminated with ultraviolet light during a time of 4 hours (λ ≅ 264 nm). We could see the effect of degraded operation in the absorbance measurement using UV-VIS spectrophotometry. The results show an increased rate of degradation of the wastewater by 30% compared to the values reflected biologically treated wastewater by anaerobic reactors.

Hetero-epitaxial growth of TiC films on MgO(001) at 100 °C by DC reactive magnetron sputtering

International Nuclear Information System (INIS)

Braic, M.; Zoita, N.C.; Danila, M.; Grigorescu, C.E.A.; Logofatu, C.

2015-01-01

Hetero-epitaxial TiC thin films were deposited at 100 °C on MgO(001) by DC reactive magnetron sputtering in a mixture of Ar and CH 4 . The 62 nm thick films were analyzed for elemental composition and chemical bonding by Auger electron spectroscopy, X-ray photoelectron spectroscopy and micro-Raman spectroscopy. The crystallographic structure investigation by high resolution X-ray diffraction revealed that the films consist of two layers: an interface partially strained epilayer with high crystalline quality, and a relaxed layer, formed by columnar grains, maintaining the epitaxial relationship with the substrate. The films presented smooth surfaces (RMS roughness ~ 0.55 nm), with circular equi-sized grains/crystallites, as observed by atomic force microscopy. The Hall measurements in Van der Pauw geometry revealed relatively high resistivity value ~ 620 μΩ cm, ascribed to electron scattering on interfaces, on grain boundaries and on different defects/dislocations. - Highlights: • Hetero-epitaxial TiC 0.84 thin films were grown on MgO(001) at 100 °C by magnetron sputtering. • 62 nm thick films were synthesized by magnetron sputtering, using Ti, Ar and CH 4 . • The film comprises a partially strained interface epilayer and a relaxed top layer. • Both layers preserve the epitaxial relationship with the substrate. • Low RMS surface roughness ~ 0.55 nm and grains with mean lateral size of ~ 38.5 nm were observed

Hetero-epitaxial growth of TiC films on MgO(001) at 100 °C by DC reactive magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Braic, M. [National Institute for Optoelectronics, 409 Atomistilor St., 077125 Magurele (Romania); Zoita, N.C., E-mail: cnzoita@inoe.ro [National Institute for Optoelectronics, 409 Atomistilor St., 077125 Magurele (Romania); Danila, M. [National Institute for Research and Development in Microtechnology, 126A Erou Iancu Nicolae Blvd., 077190 Bucharest (Romania); Grigorescu, C.E.A. [National Institute for Optoelectronics, 409 Atomistilor St., 077125 Magurele (Romania); Logofatu, C. [National Institute of Materials Physics, 105 bis Atomistilor St., 077125 Magurele (Romania)

2015-08-31

Hetero-epitaxial TiC thin films were deposited at 100 °C on MgO(001) by DC reactive magnetron sputtering in a mixture of Ar and CH{sub 4}. The 62 nm thick films were analyzed for elemental composition and chemical bonding by Auger electron spectroscopy, X-ray photoelectron spectroscopy and micro-Raman spectroscopy. The crystallographic structure investigation by high resolution X-ray diffraction revealed that the films consist of two layers: an interface partially strained epilayer with high crystalline quality, and a relaxed layer, formed by columnar grains, maintaining the epitaxial relationship with the substrate. The films presented smooth surfaces (RMS roughness ~ 0.55 nm), with circular equi-sized grains/crystallites, as observed by atomic force microscopy. The Hall measurements in Van der Pauw geometry revealed relatively high resistivity value ~ 620 μΩ cm, ascribed to electron scattering on interfaces, on grain boundaries and on different defects/dislocations. - Highlights: • Hetero-epitaxial TiC{sub 0.84} thin films were grown on MgO(001) at 100 °C by magnetron sputtering. • 62 nm thick films were synthesized by magnetron sputtering, using Ti, Ar and CH{sub 4}. • The film comprises a partially strained interface epilayer and a relaxed top layer. • Both layers preserve the epitaxial relationship with the substrate. • Low RMS surface roughness ~ 0.55 nm and grains with mean lateral size of ~ 38.5 nm were observed.

Preparation and characterization of Ti/SnO2-Sb electrode with copper nanorods for AR 73 removal

International Nuclear Information System (INIS)

Xu, Li; Li, Ming; Xu, Wei

2015-01-01

Novel Ti/Cu-NRs/SnO 2 -Sb electrode modified by copper (Cu) nanorods was fabricated through anodic aluminum oxide (AAO) template assisted electrochemical deposition (ECD) for wastewater treatment. Scanning electron microscopy (SEM), energy dispersive X-ray (EDX), X-ray diffraction (XRD) and electrochemical methods such as linear sweep voltammetry (LSV), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to characterize the surface morphology, crystal structure and electrochemical performance of the electrodes. Acid dye AR 73 was selected as target pollutants to investigate the electro-catalyst behavior, and UV/vis spectroscopy was used to monitor the concentration changes with time. The results indicated that the presence of Cu nanorods on the Ti substrate promoted the electrodes' property obviously. Ti/Cu-NRs/SnO 2 -Sb anode possessed smaller charge transfer resistance and longer service life than Ti/SnO 2 -Sb anode. The oxygen evolution potential (OEP) of Ti/Cu-NRs/SnO 2 -Sb electrodes reach 2.17 V (vs. Ag/AgCl). Removal of pollutants and reaction rate were all promoted due to the introduction of Cu nanorods in the process of AR 73 decomposing with Ti/Cu-NRs/SnO 2 -Sb electrodes. And specific energy consumption also reduced remarkably. Our study has shown that the fabricated Ti/Cu-NRs/SnO 2 -Sb electrodes are very promising for the electrochemical treatment of wastewater

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

Structure and mechanical properties of Ti-Si-C coatings deposited by magnetron sputtering

International Nuclear Information System (INIS)

Koutzaki, S.H.; Krzanowski, J.E.; Nainaparampril, J.J.

2001-01-01

Nanostructured coatings consisting of mixed carbide phases can provide a potential means to developing superhard coatings. Heterogeneous nanostructured coatings can be obtained by either deposition of multilayer structures or by depositing film compositions that undergo a natural phase separation due to thermodynamic immiscibility. In the present work, we have taken the latter approach, and deposited films by radio frequency cosputtering from dual carbide targets. We have examined a number of ternary carbide systems, and here we report the results obtained on Ti-Si-C films with a nominal (Ti 1-x Si x )C stoichiometry and with x≤0.31. It was found that the nanoindentation hardness increased with Si content, and the maximum hardness achieved was nearly twice that of sputter-deposited TiC. We further analyzed these films using high-resolution transmission electron microscopy (TEM), x-ray photoelectron spectroscopy (XPS), and x-ray diffraction. Since cubic SiC has an x-ray pattern almost identical to that of TiC, the extent of phase separation could not be determined by that method. However, XRD did demonstrate a general disordering of the films with increasing SiC content. In addition, a mottled structure was observed in high-resolution TEM images of the Si-containing films, confirming microstructural effects due to the Si additions

Properties of nano structured Ag-TiO{sub 2} composite coating on stainless steel using RF sputtering method

Energy Technology Data Exchange (ETDEWEB)

Bakar, S. Abu; Jamuna-Thevi, K.; Abu, N.; Mohd Toff, M. R. [Advanced Materials Research Centre (AMREC), SIRIM Berhad, Lot 34, Jalan Hi- Tech 2/3, Kulim Hi-Tech Park, 09000 Kulim (Malaysia)

2012-07-02

RF Sputtering system is one of the Physical Vapour Deposition (PVD) methods that have been widely used to produce hard coating. This technique is used to deposit thin layers of metallic substrates such as stainless steel (SS). From this process, a good adhesiveness and wear resistance coating can be produced for biomedical applications. In this study, RF sputtering method was used to deposit TiO{sub 2}-Ag composite coatings via various deposition parameters. The parameters are RF power of 350W, gas composition (Ar: O{sub 2}) 50:5 and deposition time at 1, 2, 4 and 6 hours. Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD) and Raman spectroscopy were used to characterize surface area of coated samples. The formation of nanocrystalline thin film and the surface morphology were examined using SEM. The crystallite size of TiO{sub 2}-Ag composite coatings were estimated between 20-60 nm based on XRD analysis using Scherer equation and SEM evaluation. The Raman and XRD results suggested that the structure of the TiO{sub 2}-Ag consist of anatase and rutile phases. It also showed that the intensity of anatase peaks increased after samples undergone annealing process at 500 Degree-Sign C.

Anisotropies in sputtered FeCoV films and FeCoV/Ti:N multilayers

Energy Technology Data Exchange (ETDEWEB)

Clemens, D.; Vananti, A.; Terrier, C.; Boeni, P.; Schnyder, B.; Tixier, S.; Horisberger, M. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1997-09-01

SQUID and MOKE magnetometry as well as mechanical and X-ray stress analysis have been used in order to prove the magnetostrictive nature of the anisotropy in Fe{sub 0.50}Co{sub 0.48}V{sub 0.02} films and Fe{sub 0.50}Co{sub 0.48}V{sub 0.02} /Ti:N multilayers. The investigation stresses on the dependence on the sputter gas pressure and on the thickness of the deposited layer. (author) 1 fig., 6 refs.

Effect of N Concentration on Microstructure Evolution of the Nanostructured (Al, Ti, SiN Coatings Prepared by d.c. Reactive Magnetron Sputtering

Directory of Open Access Journals (Sweden)

L. Jakab-Farkas

2009-12-01

Full Text Available Nanostructured (Al, Ti, SiN thin film coatings were synthesized by d.c. reactive magnetron sputtering, performed in an Ar/N2 gas mixture from a planar rectangular Al:Ti:Si=50:25:25 alloyed target. The mass flow of N2 reactive gas was strictly controlled in sputtering process. Conventional transmission electron microscopy (TEM technique was used for microstructure investigation of the as deposited films. Cross-sectional cuts performed through the deposited films revealed distinct microstructure evolution for different samples. It was found that the variation of the reactive gas amount induced changes in film microstructure. The metallic AlTiSi film exhibited strong columnar growth with a crystalline structure. The addition of a small amount of nitrogen to the process gas leads to a crystallite refinement. Further increase of N concentration resulted in evolution of fine lamellae growth morphology consisting of hainlike pearls in a dendrite, clusters of very fine grains in close crystallographic orientation.

Photocatalytic activity of self-assembled porous TiO2 nano-columns array fabricated by oblique angle sputter deposition

Science.gov (United States)

Shi, Pengjun; Li, Xibo; Zhang, Qiuju; Yi, Zao; Luo, Jiangshan

2018-04-01

A well-separated and oriented TiO2 nano-columns arrays with porous structure were fabricated by the oblique angle sputter deposition technique and subsequently annealing at 450 °C in Ar/O2 mixed atmosphere. The deposited substrate was firstly modified by a template of self-assembled close-packed arrays of 500 nm-diameter silica (SiO2) spheres. Scanning electronic microscopic (SEM) images show that the porous columnar nanostructure is formed as a result of the geometric shadowing effect and surface diffusion of the adatoms in oblique angle deposition (OAD). X-ray diffraction (XRD) measurements reveal that the physically OAD film with annealing treatment are generally mixed phase of rutile and anatase TiO2 polymorphic forms. The morphology induced absorbance and band gap tuning by different substrates was demonstrated by the UV–vis spectroscopy. The well-separated one-dimensional (1D) nano-columns array with specific large porous surface area is beneficial for charge separation in photocatalytic degradation. Compared with compact thin film, such self-assembled porous TiO2 nano-columns array fabricated by oblique angle sputter deposition performed an enhanced visible light induced photocatalytic activity by decomposing methyl orange (MO) solution. The well-designed periodic array-structured porous TiO2 films by using modified patterned substrates has been demonstrated significantly increased absorption edge in the UV-visible light region with a narrower optical band gap, which are expected to be favorable for application in photovoltaic, lithium-ion insertion and photocatalytic, etc.

Bandgap tailoring of in-situ nitrogen-doped TiO₂ sputtered films intended for electrophotocatalytic applications under solar light

Energy Technology Data Exchange (ETDEWEB)

Delegan, N.; El Khakani, M. A., E-mail: elkhakani@emt.inrs.ca [Institut National de la Recherche Scientifique, Centre Énergie, Matériaux et Télécommunications, 1650, Boulevard Lionel-Boulet, Varennes, Québec J3X-1S2 (Canada); Daghrir, R.; Drogui, P. [Institut National de la Recherche Scientifique, Centre Eau, Terre et Environnement, 490 Rue de la Couronne, Québec G1K-9A9 (Canada)

2014-10-21

We report on a reactive RF-sputtering process permitting the in-situ nitrogen doping of TiO₂ films in order to shift their photoactivity from UV to visible range. By carefully controlling the relative nitrogen-to-argon mass flow rate ratio (within the 0%–25% range) in the sputter deposition chamber, TiO₂:N films were grown with nitrogen contents ranging from 0 to 6.2 at. %, as determined by high-resolution X-ray spectroscopy measurements. A systematic investigation of the crystalline structure of the TiO₂:N films, as a function of their N content, revealed that low N contents (0.2–0.3 at. %) induce crystallization in the rutile phase while higher N contents (≥1.4 at. %) were accompanied with the recovery of the anatase structure with an average crystallite size of ~35 nm. By using both UV-Vis absorption and spectroscopic ellipsometry measurements, we were able to quantitatively determine the bandgap (E{sub g}) variation of the TiO₂:N films as a function of their N content. Thus, we have demonstrated that the E{sub g} of the TiO₂:N films effectively narrows from 3.2 eV down to a value as low as ~2.3 eV for the optimal N doping concentration of 3.4 at. % (higher N incorporation does not translate into further red shifting of the TiO₂:N films' E{sub g}). The photoactivity of the TiO₂:N films under visible light was confirmed through electro-photocatalytic decomposition of chlortetracycline (CTC, an emerging water pollutant) under standard 1.5AM solar radiation. Thus, CTC degradation efficiencies of up to 98% were achieved with 2 hours process cycles under simulated solar light. Moreover, the electro-photocatalytic performance of the TiO₂:N films is shown to be directly correlated to their optoelectronic properties (namely their bandgap narrowing).

Microstructural Analysis of TiAl x N y O z Coatings Fabricated by DC Reactive Sputtering

Science.gov (United States)

García-González, L.; Hernández-Torres, J.; Flores-Ramírez, N.; Martínez-Castillo, J.; García-Ramírez, P. J.; Muñoz-Saldaña, J.; Espinoza-Beltrán, F. J.

2009-02-01

TiAl x N y O z coatings were prepared by DC reactive sputtering on AISI D2 tool steel substrates, using a target of Ti-Al-O fabricated from a mixture of powders of Ti (22.60 wt.%), Al (24.77 wt.%), and O (52.63 wt.%). The coatings were deposited on substrates at room temperature in a reactive atmosphere of nitrogen and argon under a pressure of 8.5 × 10-3 mbar. X-ray diffraction, electron dispersive spectroscopy, Raman scattering, and nanoindentation techniques were employed to investigate the coatings. The results show that the increment in the nitrogen flow affects the structure and the mechanical properties of the coatings. The sample with the lowest nitrogen flow presented the highest hardness (10.5 GPa) and the Young’s modulus (179.5 GPa). The hardness of the coatings TiAl x N y O z as a function of crystalline grain size shows a behavior consistent with the Hall-Petch relation.

Phase composition and tribomechanical properties of Ti-B-C nanocomposite coatings prepared by magnetron sputtering

Science.gov (United States)

Sánchez-López, J. C.; Abad, M. D.; Justo, A.; Gago, R.; Endrino, J. L.; García-Luis, A.; Brizuela, M.

2012-09-01

Protective nanocomposite coatings based on hard ceramic phases (TiC, TiB2) combined with amorphous carbon (a-C) are of interest because of their adequate balance between mechanical and tribological performances. In this work, Ti-B-C nanocomposite coatings were prepared by co-sputtering of graphite and TiB2 targets. Varying the discharge power ratio applied to the graphite and TiB2 targets from 0 to 2, the a-C content in the coatings could be tuned from 0 to 60%, as observed by means of Raman and x-ray photoelectron spectroscopy (XPS). The microstructural characterization demonstrated a progressive decrease in crystallinity from an initial nanocrystalline (nc) TiB2-like structure to a distorted TiBxCy ternary compound with increasing C concentration. X-ray absorption near-edge structure measurements on the B K-edge helped to determine a hexagonal arrangement around the B atoms in the ternary TiBxCy phase. A fitting analysis of the C 1s XPS peak allowed us to evaluate the relative amount of a-C and TiBxCy components. A drastic change in hardness (from 52 to 13 GPa) and friction coefficient values (from 0.8 to 0.2) is noticed when moving from nc-TiB2 to TiBC/a-C nanocomposites. The fraction of a-C necessary to decrease the friction below 0.2 was found to be 45%. Raman observation of the wear tracks determined the presence of disordered sp2-bonded carbon phase associated with the diminution of the friction level.

Adhesive and tribocorrosive behavior of TiAlPtN/TiAlN/TiAl multilayers sputtered coatings over CoCrMo

Science.gov (United States)

Canto, C. E.; Andrade, E.; Rocha, M. F.; Alemón, B.; Flores, M.

2017-09-01

The tribocorrosion resistance and adherence of multilayer coatings of TiAlPtN/TiAlN/TiAl synthesized by PVD reactive magnetron sputtering over a CoCrMo alloy substrate in 10 periods of 30 min each were analyzed and compared to those of the substrate alone and to that of a TiAlPtN single layer coating of the same thickness. The objective of the present work was to create multilayers with different amounts of Pt in order to enhance the tribocorrosion resistance of a biomedical alloy of CoCrMo. Tribocorrosion tests were performed using Simulated Body Fluid (SBF) at typical body temperature with a tribometer in a pin on disk test. The elemental composition and thickness of the coating which behave better at the tribocorrosion tests were evaluated by means of RBS (Rutherford Backscattering Spectroscopy) IBA (Ion Beam Analysis) technique, using an alpha particles beam of 1.8 MeV, before and after the reciprocating motion in the tribocorrosion test. In order to simulate the elemental profile of the samples, the SIMNRA simulation computer code was used. Measurements of the adhesion of the coatings to the substrate were carried on by means of a scratch test using a tribometer. By taking micrographs of the produced tracks, the critical loads at which the coatings are fully separated from the substrate were determined. From these tests it was observed that a coating with 10 min of TiAlPtN in a TiAlPtN/TiAl period of 30 min in multilayers of 10 periods and with an average thickness of 145 nm for the TiAlPtN nanolayers had the best tribocorrosion resistance behavior, compared to that of the CoCrMo alloy. The RBS experiments showed a reduction of the thickness of the films along with some loss of the multilayer structure after the reciprocating motion. The adhesion tests indicated that the multilayer with the average TiAlPtN thickness of 145 nm displayed the highest critical load. These results indicate a high correlation between the adherence and the tribocorrosion behavior.

Biocompatibility and Surface Properties of TiO2 Thin Films Deposited by DC Magnetron Sputtering

Science.gov (United States)

López-Huerta, Francisco; Cervantes, Blanca; González, Octavio; Hernández-Torres, Julián; García-González, Leandro; Vega, Rosario; Herrera-May, Agustín L.; Soto, Enrique

2014-01-01

We present the study of the biocompatibility and surface properties of titanium dioxide (TiO2) thin films deposited by direct current magnetron sputtering. These films are deposited on a quartz substrate at room temperature and annealed with different temperatures (100, 300, 500, 800 and 1100 °C). The biocompatibility of the TiO2 thin films is analyzed using primary cultures of dorsal root ganglion (DRG) of Wistar rats, whose neurons are incubated on the TiO2 thin films and on a control substrate during 18 to 24 h. These neurons are activated by electrical stimuli and its ionic currents and action potential activity recorded. Through X-ray diffraction (XRD), the surface of TiO2 thin films showed a good quality, homogeneity and roughness. The XRD results showed the anatase to rutile phase transition in TiO2 thin films at temperatures between 500 and 1100 °C. This phase had a grain size from 15 to 38 nm, which allowed a suitable structural and crystal phase stability of the TiO2 thin films for low and high temperature. The biocompatibility experiments of these films indicated that they were appropriated for culture of living neurons which displayed normal electrical behavior. PMID:28788667

Characterization and properties Ti-Al-Si-N nanocomposite coatings prepared by middle frequency magnetron sputtering

Science.gov (United States)

Zou, C. W.; Zhang, J.; Xie, W.; Shao, L. X.; Guo, L. P.; Fu, D. J.

2011-10-01

TiN-containing amorphous Ti-Al-Si-N (nc-TiN/a-Si 3N 4 or a-AlN) nanocomposite coatings were deposited by using a modified closed field twin unbalanced magnetron sputtering system which is arc assisted and consists of two circles of targets, at a substrate temperature of 300 °C. XRD, XPS and High-resolution TEM experiments showed that the coatings contain TiN nanocrystals embedded in the amorphous Si 3N 4 or AlN matrix. The coatings exhibit good mechanical properties that are greatly influenced by the Si contents. The hardness of the Ti-Al-Si-N coatings deposited at Si targets currents of 5, 8, 10, and 12 A were 45, 47, 54 and 46 GPa, respectively. The high hardness of the deposited Ti-Al-Si-N coatings may be own to the plastic distortion and dislocation blocking by the nanocrystalline structure. On the other hand, the friction coefficient decreases monotonously with increasing Si contents. This result would be caused by tribo-chemical reactions, which often take place in many ceramics, e.g. Si 3N 4 reacts with H 2O to produce SiO 2 or Si(OH) 2 tribolay-layer.

Effects of annealing temperatures on the morphological, mechanical, surface chemical bonding, and solar selectivity properties of sputtered TiAlSiN thin films

International Nuclear Information System (INIS)

Rahman, M. Mahbubur; Jiang, Zhong-Tao; Zhou, Zhi-feng; Xie, Zonghan; Yin, Chun Yang; Kabir, Humayun; Haque, Md. Mahbubul; Amri, Amun; Mondinos, Nicholas; Altarawneh, Mohammednoor

2016-01-01

Quaternary sputtered TiAlSiN coatings were investigated for their high temperature structural stability, surface morphology, mechanical behaviors, surface chemical bonding states, solar absorptance and thermal emittance for possible solar selective surface applications. The TiAlSiN films were synthesized, via unbalanced magnetron sputtered technology, on AISI M2 steel substrate and annealed at 500 °C - 800 °C temperature range. SEM micrographs show nanocomposite-like structure with amorphous grain boundaries. Nanoindentation analyses indicate a decrease of hardness, plastic deformation and constant yield strength for the coatings. XPS analysis show mixed Ti, Al and Si nitride and oxide as main coating components but at 800 °C the top layer of the coatings is clearly composed of only Ti and Al oxides. Synchrotron radiation XRD (SR-XRD) results indicate various Ti, Al and Si nitride and oxide phases, for the above annealing temperature range with a phase change occurring with the Fe component of the substrate. UV–Vis spectroscopy, FTIR spectroscopy studies determined a high solar selectivity, s of 24.6 for the sample annealed at 600 °C. Overall results show good structural and morphological stability of these coatings at temperatures up to 800 °C with a very good solar selectivity for real world applications. - Highlights: • TiAlSiN sputtered coatings were characterized for solar selective applications. • In situ synchrotron radiation XRD were studies show the occurrence of multiple stable phases. • A high selectivity of 24.63 has been achieved for the coatings annealed at 700 °C. • Existence of XRD phases were also confirmed by XPS measurements. • At high temperature annealing the mechanical properties of films were governed by the utmost surfaces of the films.

Recubrimientos de (ti,aln sobre acero aisi 4140 por sputtering reactivo

Directory of Open Access Journals (Sweden)

DANNA GARCIA

2007-01-01

Full Text Available Empleando la técnica de Pulverización catódica con radiofrecuencia y magnetrón (Magnetron Sputtering RF, se prepararon películas de (Ti,AlN sobre sustratos de acero AISI 4140. Se utilizó un blanco formado con polvos metálicos de Ti y Al, con composición nominal 60% Ti y 40% Al (porcentaje en átomos y una razón de presiones parciales de nitrógeno - argón, PN2/PAr de 0,1 aproximadamente; la temperatura del sustrato se varió entre 260 y 330 ºC y el tiempo de deposición entre 2 y 4,5 horas para obtener películas con diferentes espesores. La composición química de las películas se determinó mediante la técnica de energía dispersada de rayos X (EDX, y su topografía mediante microscopía de fuerza atómica (AFM. Igualmente se midió micro dureza, y se determinó su comportamiento electroquímico mediante espectroscopia de impedancia electroquímica EIS y ensayos TAFEL. Las películas obtenidas presentaron granos globulares, uniformes y de pequeño diámetro, con características electroquímicas de protección al sustrato frente a procesos de corrosión.

Electronic excitation of Ti atoms sputtered by energetic Ar+ and He+ from clean and monolayer oxygen covered surfaces

International Nuclear Information System (INIS)

Pellin, M.J.; Gruen, D.M.; Young, C.E.; Wiggins, M.D.; Argonne National Lab., IL

1983-01-01

Electronic excitation of Ti atoms ejected during energetic ion bombardment (Ar + , He + ) of well characterized clean and oxygen covered polycrystalline Ti metal surfaces has been determined. For states with 0 to 2 eV and 3 to 5.5 eV of electronic energy, static mode laser fluorescence spectroscopy (LFS) and static mode spontaneous fluorescence spectroscopy (SFS) were used respectively. These experiments which were carried out in a UHV ( -10 Torr) system equipped with an Auger spectrometer provide measurements of the correlation between oxygen coverage (0 to 3 monolayers) and the excited state distribution of sputtered Ti atoms. The experimentally determined electronic partition function of Ti atoms does not show an exponential dependence on energy (E) above the ground state but rather an E -2 or E -3 power law dependence. (orig.)

Experimental study on TiN coated racetrack-type ceramic pipe

Science.gov (United States)

Wang, Jie; Xu, Yan-Hui; Zhang, Bo; Wei, Wei; Fan, Le; Pei, Xiang-Tao; Hong, Yuan-Zhi; Wang, Yong

2015-11-01

TiN film was coated on the internal surface of a racetrack-type ceramic pipe by three different methods: radio-frequency sputtering, DC sputtering and DC magnetron sputtering. The deposition rates of TiN film under different coating methods were compared. The highest deposition rate was 156 nm/h, which was obtained by magnetron sputtering coating. Based on AFM, SEM and XPS test results, the properties of TiN film, such as film roughness and surface morphology, were analyzed. Furthermore, the deposition rates were studied with two different cathode types, Ti wires and Ti plate. According to the SEM test results, the deposition rate of TiN/Ti film was about 800 nm/h with Ti plate cathode by DC magnetron sputtering. Using Ti plate cathode rather than Ti wire cathode can greatly improve the film deposition rate. Supported by National Nature Science Foundation of China (11075157)

RF Magnetron Sputtering Deposited W/Ti Thin Film For Smart Window Applications

Science.gov (United States)

Oksuz, Lutfi; Kiristi, Melek; Bozduman, Ferhat; Uygun Oksuz, Aysegul

2014-10-01

Electrochromic (EC) devices can change reversible and persistent their optical properties in the visible region (400-800 nm) upon charge insertion/extraction according to the applied voltage. A complementary type EC is a device containing two electrochromic layers, one of which is anodically colored such as vanadium oxide (V2 O5) while the other cathodically colored such as tungsten oxide (WO3) which is separated by an ionic conduction layer (electrolyte). The use of a solid electrolyte such as Nafion eliminates the need for containment of the liquid electrolyte, which simplifies the cell design, as well as improves safety and durability. In this work, the EC device was fabricated on a ITO/glass slide. The WO3-TiO2 thin film was deposited by reactive RF magnetron sputtering using a 2-in W/Ti (9:1%wt) target with purity of 99.9% in a mixture gas of argon and oxygen. As a counter electrode layer, V2O5 film was deposited on an ITO/glass substrate using V2O3 target with the same conditions of reactive RF magnetron sputtering. Modified Nafion was used as an electrolyte to complete EC device. The transmittance spectra of the complementary EC device was measured by optical spectrophotometry when a voltage of +/-3 V was applied to the EC device by computer controlled system. The surface morphology of the films was characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM) (Fig. 2). The cyclic voltammetry (CV) for EC device was performed by sweeping the potential between +/-3 V at a scan rate of 50 mV/s.

Biomimetic growth and substrate dependent mechanical properties of bone like apatite nucleated on Ti and magnetron sputtered TiO2 nanostructure

Science.gov (United States)

Sarma, Bimal K.; Das, Apurba; Barman, Pintu; Pal, Arup R.

2016-04-01

This report presents findings on biomimetic growth of hydroxyapatite (HAp) nanocrystals on Ti and sputtered TiO2 substrates. The possibility of TiO2 nanostructure as candidate materials for future biomedical applications has been explored through the comparison of microstructural and mechanical properties of bone like apatite grown on Ti and nano-TiO2 surfaces. Raman spectroscopy and x-ray diffraction studies reveal formation of carbonate apatite with apparent domain size in the nanoscale range. A better interaction at the nano-TiO2/nano-HAp interface due to higher interfacial area could promote the growth of bone like apatite. The crystal phases, crystallinity, and surface morphology of nano-TiO2 are considered as parameters to understand the nucleation and growth of apatite with different mechanical properties at the nanoscale. The methodology of x-ray line profile analysis encompasses deconvolution of merged peaks by preserving broadening due to nanosized HAp aggregates. The Young’s modulus of bone like apatite exhibits crystallographic directional dependence which suggests the presence of elastic anisotropy in bone like apatite. The lattice contraction in the c-direction is associated with the degree of carbonate substitution in the apatite lattice. The role of residual stress is critical for the lattice distortion of HAp deposited at physiological conditions of temperature and pH of human blood plasma. The ion concentration is crucial for the uniformity, crystallinity, and mechanical behaviour of the apatite.

Biomimetic growth and substrate dependent mechanical properties of bone like apatite nucleated on Ti and magnetron sputtered TiO2 nanostructure

International Nuclear Information System (INIS)

Sarma, Bimal K; Das, Apurba; Barman, Pintu; Pal, Arup R

2016-01-01

This report presents findings on biomimetic growth of hydroxyapatite (HAp) nanocrystals on Ti and sputtered TiO 2 substrates. The possibility of TiO 2 nanostructure as candidate materials for future biomedical applications has been explored through the comparison of microstructural and mechanical properties of bone like apatite grown on Ti and nano-TiO 2 surfaces. Raman spectroscopy and x-ray diffraction studies reveal formation of carbonate apatite with apparent domain size in the nanoscale range. A better interaction at the nano-TiO 2 /nano-HAp interface due to higher interfacial area could promote the growth of bone like apatite. The crystal phases, crystallinity, and surface morphology of nano-TiO 2 are considered as parameters to understand the nucleation and growth of apatite with different mechanical properties at the nanoscale. The methodology of x-ray line profile analysis encompasses deconvolution of merged peaks by preserving broadening due to nanosized HAp aggregates. The Young’s modulus of bone like apatite exhibits crystallographic directional dependence which suggests the presence of elastic anisotropy in bone like apatite. The lattice contraction in the c-direction is associated with the degree of carbonate substitution in the apatite lattice. The role of residual stress is critical for the lattice distortion of HAp deposited at physiological conditions of temperature and pH of human blood plasma. The ion concentration is crucial for the uniformity, crystallinity, and mechanical behaviour of the apatite. (paper)

Nanoscale compositional analysis of NiTi shape memory alloy films deposited by DC magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Sharma, S. K.; Mohan, S. [Centre for Nano Science and Engineering, Indian Institute of Science, Bangalore-560012 (India); Bysakh, S. [Central Glass and Ceramics Research Institute, Kolkata-700032 (India); Kumar, A.; Kamat, S. V. [Defence Metallurgical Research Laboratory, Hyderabad-500058 (India)

2013-11-15

The formation of surface oxide layer as well as compositional changes along the thickness for NiTi shape memory alloy thin films deposited by direct current magnetron sputtering at substrate temperature of 300 °C in the as-deposited condition as well as in the postannealed (at 600 °C) condition have been thoroughly studied by using secondary ion mass spectroscopy, x-ray photoelectron spectroscopy, and scanning transmission electron microscopy-energy dispersive x-ray spectroscopy techniques. Formation of titanium oxide (predominantly titanium dioxide) layer was observed in both as-deposited and postannealed NiTi films, although the oxide layer was much thinner (8 nm) in as-deposited condition. The depletion of Ti and enrichment of Ni below the oxide layer in postannealed films also resulted in the formation of a graded microstructure consisting of titanium oxide, Ni{sub 3}Ti, and B2 NiTi. A uniform composition of B2 NiTi was obtained in the postannealed film only below a depth of 200–250 nm from the surface. Postannealed film also exhibited formation of a ternary silicide (Ni{sub x}Ti{sub y}Si) at the film–substrate interface, whereas no silicide was seen in the as-deposited film. The formation of silicide also caused a depletion of Ni in the film in a region ∼250–300 nm just above the film substrate interface.

Self-organized nanocrack networks: a pathway to enlarge catalytic surface area in sputtered ceramic thin films, showcased for photocatalytic TiO2

Science.gov (United States)

Henkel, B.; Vahl, A.; Aktas, O. C.; Strunskus, T.; Faupel, F.

2018-01-01

Sputter deposited photocatalytic thin films offer high adherence and mechanical stability, but typically are outperformed in their photocatalytic properties by colloidal TiO2 nanostructures, which in turn typically suffer from problematic removal. Here we report on thermally controlled nanocrack formation as a feasible and batch applicable approach to enhance the photocatalytic performance of well adhering, reactively sputtered TiO2 thin films. Networks of nanoscopic cracks were induced into tailored columnar TiO2 thin films by thermal annealing. These deep trenches are separating small bundles of TiO2 columns, adding their flanks to the overall catalytically active surface area. The variation of thin film thickness reveals a critical layer thickness for initial nanocrack network formation, which was found to be about 400 nm in case of TiO2. The columnar morphology of the as deposited TiO2 layer with weak bonds between respective columns and with strong bonds to the substrate is of crucial importance for the formation of nanocrack networks. A beneficial effect of nanocracking on the photocatalytic performance was experimentally observed. It was correlated by a simple geometric model for explaining the positive impact of the crack induced enlargement of active surface area on photocatalytic efficiency. The presented method of nanocrack network formation is principally not limited to TiO2 and is therefore seen as a promising candidate for utilizing increased surface area by controlled crack formation in ceramic thin films in general.

The microstructure and wettability of the TiO{sub x} films synthesized by reactive DC magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Lin Zeng [School of Mechanical Engineering and Automation, Northeastern University, Shenyang 110004 (China); State Key Laboratory of Plastic Forming Simulation and Die and Mould Technology Wuhan, Hubei 430074 (China)], E-mail: linzengsy@gmail.com; Liu Kun; Zhang Yichen; Yue Xiangji; Song Guiqiu [School of Mechanical Engineering and Automation, Northeastern University, Shenyang 110004 (China); Ba Dechun [School of Mechanical Engineering and Automation, Northeastern University, Shenyang 110004 (China)], E-mail: dechunba@yahoo.com

2009-01-25

Different chemical state of titanium oxide films were deposited on commercially pure Ti (CP Ti) by reactive DC magnetron sputtering under different oxygen flow rates to examine a possibility of their applications to endovascular stents. The chemical composition and crystal structure of the obtained films were analyzed by XPS and XRD, respectively. In dependence on the deposition parameters employed, the obtained films demonstrated different mixture of anatase TiO{sub 2}, Ti{sub 2}O{sub 3}, TiO and Ti. The wettability of the films was measured by the water contact angle variation. By formation of titanium oxide film on CP Ti, contact angle was decreased. In order to modify and control the surface wettability, the resultant TiO{sub x} films were etched subsequently by different plasma. The wettability was influenced by etched process according to the decreased contact angle values of etched TiO{sub x} film. Furthermore, TiO{sub x} films became highly hydrophilic by ultraviolet (UV) irradiation, and returned to the initial relatively hydrophobic state by visible-light (VIS) irradiation. The wettability of the TiO{sub x} film was enabled to convert between hydrophilic and hydrophobic reversibly by alternative UV and VIS irradiation. By adjusting deposition parameter and further modification process, the wettability of the TiO{sub x} films can be changed freely in the range of 0-90 deg.

CdSe nanorod/TiO2 nanoparticle heterojunctions with enhanced solar- and visible-light photocatalytic activity

Directory of Open Access Journals (Sweden)

Fakher Laatar

2017-12-01

Full Text Available CdSe nanorods (NRs with an average length of ≈120 nm were prepared by a solvothermal process and associated to TiO2 nanoparticles (Aeroxide® P25 by annealing at 300 °C for 1 h. The content of CdSe NRs in CdSe/TiO2 composites was varied from 0.5 to 5 wt %. The CdSe/TiO2 heterostructured materials were characterized by XRD, TEM, SEM, XPS, UV–visible spectroscopy and Raman spectroscopy. TEM images and XRD patterns show that CdSe NRs with wurtzite structure are associated to TiO2 particles. The UV–visible spectra demonstrate that the narrow bandgap of CdSe NRs serves to increase the photoresponse of CdSe/TiO2 composites until ≈725 nm. The CdSe (2 wt %/TiO2 composite exhibits the highest photocatalytic activity for the degradation of rhodamine B in aqueous solution under simulated sunlight or visible light irradiation. The enhancement in photocatalytic activity likely originates from CdSe sensitization of TiO2 and the heterojunction between these materials which facilitates electron transfer from CdSe to TiO2. Due to its high stability (up to ten reuses without any significant loss in activity, the CdSe/TiO2 heterostructured catalysts show high potential for real water decontamination.

Development of Dye-Sensitized Solar Cells with Sputtered N-Doped TiO2 Thin Films: From Modeling the Growth Mechanism of the Films to Fabrication of the Solar Cells

OpenAIRE

Duarte, D. A.; Massi, M.; da Silva Sobrinho, A. S.

2014-01-01

In this paper, nitrogen-doped TiO2 thin films were deposited by DC reactive sputtering at different doping levels for the development of dye-sensitized solar cells. The mechanism of film growth during the sputtering process and the effect of the nitrogen doping on the structural, optical, morphological, chemical, and electronic properties of the TiO2 were investigated by numerical modeling and experimental methods. The influence of the nitrogen doping on the working principle of the prototype...

Overcoming challenges to the formation of high-quality polycrystalline TiO{sub 2}:Ta transparent conducting films by magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Neubert, M.; Cornelius, S.; Fiedler, J. [Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, P.O. Box 510119, 01314 Dresden (Germany); Gebel, T.; Liepack, H. [DTF Technology GmbH, 01108 Dresden (Germany); Kolitsch, A. [Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, P.O. Box 510119, 01314 Dresden (Germany); HZDR Innovation GmbH, 01328 Dresden (Germany); Vinnichenko, M. [Fraunhofer-Institut für Keramische Technologien und Systeme, 01277 Dresden (Germany)

2013-08-28

The work is focused on understanding the physical processes responsible for the modification of the structure, electrical and optical properties of polycrystalline TiO{sub 2}:Ta films formed by annealing of initially amorphous films grown by direct current magnetron sputtering of electrically conductive ceramic targets. It is shown that fine tuning of the oxygen content during deposition of amorphous TiO{sub 2}:Ta films is critical to achieving low resistivity and high optical transmittance after annealing. Increasing the total pressure during magnetron sputter deposition is shown to decrease the sensitivity of the annealed films to the oxygen flow variation during deposition of the initially amorphous layers. Polycrystalline anatase TiO{sub 2}:Ta films of low electrical resistivity (ρ{sub H} = 1.5 × 10{sup −3}Ω cm), high free electron mobility (μ{sub H} = 8 cm{sup 2}/Vs), and low extinction (k{sub 550nm} = 0.006) are obtained in this way at a total pressure of 2 Pa. The dependence of the polycrystalline film electrical properties on the oxygen content is discussed in terms of Ta dopant electrical activation/deactivation taking into account the formation of compensating defects at different oxygen pressures. The temperature-dependent transport of the polycrystalline anatase TiO{sub 2}:Ta films is investigated showing the dominant role of the optical phonon scattering in the case of films with an optimum Ti/O ratio.

Enhancement of Ti-containing hydrogenated carbon (Tisbnd C:H) films by high-power plasma-sputtering

Science.gov (United States)

Gwo, Jyh; Chu, Chun-Lin; Tsai, Ming-Jui; Lee, Shyong

2012-02-01

Ti-containing amorphous hydrogenated carbon (Tisbnd C:H) thin films were deposited on stainless steel SS304 substrates by high-power pulsed magnetron sputtering (HPPMS) in an atmosphere of mixed Ar and C2H2 gases using titanium metal as the cathodic material. The multilayer structure of the deposited film had a Tisbnd TiCsbnd DLC gradient to improve adhesion and reduce residual stress. This study investigates the effects of substrate bias and target-to-substrate distance on the mechanical properties of Tisbnd C:H films. Film properties, including composition, morphology, microstructure, mechanical, and tribology, were examined by glow discharge spectroscopy (GDS), scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, and a nanoindenter and a pin-on-disk tribometer. Experiments revealed impressive results.

Preparation and characterization of photocatalytic performance of hierarchical heterogeneous nanostructured ZnO/TiO2 films made by DC magnetron sputtering

International Nuclear Information System (INIS)

Le Phuc Quy; Vu Thi Hanh Thu

2013-01-01

With the aim to enhance photocatalytic properties and anti-Ecoli bacteria abilities of TiO 2 thin films; hierarchical heterogeneous nanostructured ZnO/TiO 2 (HN s ) films were deposited by DC magnetron sputtering. The obtained results showed that both the photocatalytic performance and anti-Ecoli bacteria ability of HN s films exhibited enhancement in comparison with standard TiO 2 films. This enhancement was explained due to the reduction of the electron - hole recombination and the red shift of absorption edge of the HNs films. (author)

Oxidation and Tribological Behavior of Ti-B-C-N-Si Nanocomposite Films Deposited by Pulsed Unbalanced Magnetron Sputtering.

Science.gov (United States)

Jang, Jaeho; Heo, Sungbo; Kim, Wang Ryeol; Kim, Jun-Ho; Nam, Dae-Geun; Kim, Kwang Ho; Park, Ikmin; Park, In-Wook

2018-03-01

Quinary Ti-B-C-N-Si nanocomposite films were deposited onto AISI 304 substrates using a pulsed d.c. magnetron sputtering system. The quinary Ti-B-C-N-Si (5 at.%) film showed excellent tribological and wear properties compared with those of the Ti-B-C-N films. The steady friction coefficient of 0.151 and a wear rate of 2 × 10-6 mm3N-1m-1 were measured for the Ti-B-C-N-Si films. The oxidation behavior of Ti-B-C-N-Si nanocomposite films was systematically investigated using X-ray diffraction (XRD), and thermal analyzer with differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). It is concluded that the addition of Si into the Ti-B-C-N film improved the tribological properties and oxidation resistance of the Ti-B-C-N-Si films. The improvements are due to the formation of an amorphous SiOx phase, which plays a major role in the self-lubricant tribo-layers and oxidation barrier on the film surface or in the grain boundaries, respectively.

The Analysis Of Structure For The Multi-Layered Of Ge/TiO2 Films Prepared By The Differential Prressure Co-Sputtering

Directory of Open Access Journals (Sweden)

Adachi Y.

2015-06-01

Full Text Available We tried to fabricate the Ge/TiO2 composite films with the differential pressure (pumping co-sputtering (DPCS apparatus in order to improve the optical properties. In the study, the micro structure of these thin films has been evaluated. TEM image revealed that the thin film was alternately layered with TiO2 and Ge, lattice fringes were observed both of Ge layer and TiO2 layer. There were portions that lattice fringe of Ge was disturbed near the interface of Ge and TiO2. X-ray photoelectron spectroscopy elucidated that there were few germanium oxides and a part with the thin film after annealed.

Phase composition and tribomechanical properties of Ti-B-C nanocomposite coatings prepared by magnetron sputtering

International Nuclear Information System (INIS)

Sánchez-López, J C; Abad, M D; Justo, A; Gago, R; Endrino, J L; García-Luis, A; Brizuela, M

2012-01-01

Protective nanocomposite coatings based on hard ceramic phases (TiC, TiB 2 ) combined with amorphous carbon (a-C) are of interest because of their adequate balance between mechanical and tribological performances. In this work, Ti-B-C nanocomposite coatings were prepared by co-sputtering of graphite and TiB 2 targets. Varying the discharge power ratio applied to the graphite and TiB 2 targets from 0 to 2, the a-C content in the coatings could be tuned from 0 to 60%, as observed by means of Raman and x-ray photoelectron spectroscopy (XPS). The microstructural characterization demonstrated a progressive decrease in crystallinity from an initial nanocrystalline (nc) TiB 2 -like structure to a distorted TiB x C y ternary compound with increasing C concentration. X-ray absorption near-edge structure measurements on the B K-edge helped to determine a hexagonal arrangement around the B atoms in the ternary TiB x C y phase. A fitting analysis of the C 1s XPS peak allowed us to evaluate the relative amount of a-C and TiB x C y components. A drastic change in hardness (from 52 to 13 GPa) and friction coefficient values (from 0.8 to 0.2) is noticed when moving from nc-TiB 2 to TiBC/a-C nanocomposites. The fraction of a-C necessary to decrease the friction below 0.2 was found to be 45%. Raman observation of the wear tracks determined the presence of disordered sp 2 -bonded carbon phase associated with the diminution of the friction level.

Alcatel-Lucent Network Routing Specialist II (NRS II) Self-Study Guide Preparing for the NRS II Certification Exams

CERN Document Server

Warnock, Glenn

2011-01-01

The definitive resource for the NRS II exams—three complete courses in a book Alcatel-Lucent is a world leader in designing and developing scalable systems for service providers. If you are a network designer or operator who uses Alcatel-Lucent's 7750 family of service routers, prepare for certification as an A-L network routing specialist with this complete self-study course. You'll get thorough preparation for the NRS II exams while you learn to build state-of-the-art, scalable IP/MPLS-based service networks. The book provides you with an in-depth understanding of the protocols and tec

Characterization and temperature controlling property of TiAlN coatings deposited by reactive magnetron co-sputtering

International Nuclear Information System (INIS)

Chen, J.T.; Wang, J.; Zhang, F.; Zhang, G.A.; Fan, X.Y.; Wu, Z.G.; Yan, P.X.

2009-01-01

Titanium aluminum nitride (TiAlN) ternary coating is a potential material which is expected to be applied on satellite for thermal controlling. In order to investigate thermal controlling property, TiAlN coatings were deposited on Si wafers with different N 2 and Ar flux ratio by reactive magnetron co-sputtering. The structure, morphology, chemical composition and optical reflectance are investigated by X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), atom force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and spectrophotometer, respectively. The orientation of the coatings depends on the N 2 /Ar flux ratio. The coatings deposited with N 2 /Ar ratio of 10, 30 and 60% show the cubic-TiN [2 2 0] preferred orientation and the coating deposited with N 2 /Ar ratio of 100% exhibits the phase of hexagonal-AlN and cubic-TiN. The surface of the coatings becomes more compact and smoother with the N 2 /Ar ratios increase. XPS spectrum indicates that the oxides (TiO 2 and Al 2 O 3 ), oxynitride (TiN x O y ) and nitrides (TiN and AlN x ) appear at the surface of the coatings. Ignoring internal power, the optimum equilibrium temperature of TiAlN coatings is 18 deg. C and the equilibrium temperature after heat-treated has slight change, which provides the prospective application on thermal controlling

Multi-Scale-Porosity TiO2 scaffolds grown by innovative sputtering methods for high throughput hybrid photovoltaics

Science.gov (United States)

Sanzaro, Salvatore; Smecca, Emanuele; Mannino, Giovanni; Bongiorno, Corrado; Pellegrino, Giovanna; Neri, Fortunato; Malandrino, Graziella; Catalano, Maria Rita; Condorelli, Guglielmo Guido; Iacobellis, Rosabianca; De Marco, Luisa; Spinella, Corrado; La Magna, Antonino; Alberti, Alessandra

2016-12-01

We propose an up-scalable, reliable, contamination-free, rod-like TiO2 material grown by a new method based on sputtering deposition concepts which offers a multi-scale porosity, namely: an intra-rods nano-porosity (1-5 nm) arising from the Thornton’s conditions and an extra-rods meso-porosity (10-50 nm) originating from the spatial separation of the Titanium and Oxygen sources combined with a grazing Ti flux. The procedure is simple, since it does not require any template layer to trigger the nano-structuring, and versatile, since porosity and layer thickness can be easily tuned; it is empowered by the lack of contaminations/solvents and by the structural stability of the material (at least) up to 500 °C. Our material gains porosity, stability and infiltration capability superior if compared to conventionally sputtered TiO2 layers. Its competition level with chemically synthesized reference counterparts is doubly demonstrated: in Dye Sensitized Solar Cells, by the infiltration and chemisorption of N-719 dye (˜1 × 1020 molecules/cm3); and in Perovskite Solar Cells, by the capillary infiltration of solution processed CH3NH3PbI3 which allowed reaching efficiency of 11.7%. Based on the demonstrated attitude of the material to be functionalized, its surface activity could be differently tailored on other molecules or gas species or liquids to enlarge the range of application in different fields.

Improved performance of dye-sensitized solar cell with a specially tailored TiO{sub 2} compact layer prepared by RF magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Abdullah, M.H., E-mail: hanapiah801@ppinang.uitm.edu.my [NANO-Electronic Centre, Faculty of Electrical Engineering, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor (Malaysia); Rusop, M. [NANO-Electronic Centre, Faculty of Electrical Engineering, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor (Malaysia); NANO-SciTech Centre, Institute of Science, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor (Malaysia)

2014-07-05

Highlights: • A novel gradient index antireflective TiO{sub 2} compact layer based DSSC was fabricated. • Higher right-shifted transmittance spectra favour the spectral response of N719 dye. • The arc-TiO{sub 2} film on ITO has decreased the charge interfacial resistance, R{sub 1}. • The arc-TiO{sub 2} film prevents electrons recombination at ITO and nc-TiO{sub 2} interfaces. • Almost 42% increment in the overall efficiency compared to the bare ITO cell. - Abstract: We demonstrate that a graded index TiO{sub 2} antireflective compact layer (arc-TiO{sub 2}) employed by RF sputtering can modulate the optical transmittance and reduce the electron recombination in dye-sensitized solar cell (DSSC). The spectral response of the DSSC is improved, due to higher and red-shifted transmittance spectra in a specific region that favours the sensitization effect of the dye. The effects of arc-TiO{sub 2} prepared at various RF sputtering powers to the performances of DSSC were investigated by means of the incident photo to current efficiency (IPCE), open-circuit voltage decay (OCVD) and electrochemical impedance spectroscopy (EIS). The slow decay of the photo-voltage attributed to the desirable merits of the arc-TiO{sub 2} compact layer has been evidenced by the OCVD measurement. Meanwhile, the improvement of adhesion between an arc-TiO{sub 2} film and porous-TiO{sub 2} has decreased the interfacial-charge resistance, R{sub 1} in the EIS measurement. This lower R{sub 1} then facilitates the charge-transfer process of the electron in the DSSC. At 100 W of RF power, these blended effects improved the overall conversion efficiency of the DSSC by an increase of 42% compared to the cell without the compact layer.

High-induction nanocrystalline soft magnetic Fe{sub X}Ti{sub Y}B{sub Z} films prepared by magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Sheftel, Elena N.; Tedzhetov, Valentin A.; Harin, Eugene V.; Usmanova, Galina Sh. [A.A. Baikov Institute of Metallurgy and Material Science, Russian Academy of Sciences, Moscow (Russian Federation); Kiryukhantsev-Korneev, Filipp V. [National University of Science and Technology ' ' MISIS' ' , Moscow (Russian Federation)

2016-12-15

To design films with the Fe/TiB{sub 2} nanocomposite structure, which are characterized by high saturation induction B{sub s}, the phase and structural states and static magnetic properties of Fe-TiB{sub 2} films prepared by magnetron sputtering and subjected to subsequent annealing have been studied. According to X-ray diffraction data, either amorphous or nanocrystalline single-phase structure (an α-Fe(Ti,B) supersaturated solid solution with a bcc crystal lattice) is formed in the as-sputtered films. Depending on the film composition, the grain size of the α-Fe(Ti,B) phase varies from 45.6 to 6.5 nm; grains are characterized by high microstrain (0.21-4.96%). The annealing at 200-500 C leads to a decrease in the lattice parameter of the α-Fe(Ti,B) phase, i.e. to its depletion of titanium and boron and to the formation of two-phase α-Fe + Fe{sub 3}B structure after annealing at 500 C. The annealing at 200-500 C almost does not affect the grain size and microstrain of the bcc α-Fe-based phase. The amorphous state of the films is stable up to 500 C. All studied films are ferromagnets; the saturation induction B{sub s}(0.95-2.13 T) and coercive field H{sub c} (0.4-5 kA/m) of the films were determined. Correlations between the B{sub s} and H{sub c} magnitudes and the chemical composition of the films, their phase and structural states and magnetic structure are discussed. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Influence of Ge addition on the morphology and properties of TiN thin films deposited by magnetron sputtering

International Nuclear Information System (INIS)

Sandu, C.S.; Sanjines, R.; Benkahoul, M.; Parlinska-Wojtan, M.; Karimi, A.; Levy, F.

2006-01-01

Thin films of TM-X-N (TM stands for early transition metal and X = Si, Al, etc.) are used as protective coatings. The most investigated among the ternary composite systems is Ti-Si-N. The system Ti-Ge-N has been chosen to extend the knowledge about the formation of nanocomposite films. Ti-Ge-N thin films were deposited by reactive magnetron sputtering on Si and WC-Co substrates at T s = 240 deg. C, from confocal Ti and Ge targets in mixed Ar/N 2 atmosphere. The nitrogen partial pressure and the power on the Ti target were kept constant, while the power on the Ge target was varied in order to obtain various Ge concentrations in the films. No presence of Ge-N bonds was detected, while X-ray photoelectron spectroscopy measurements revealed the presence of Ti-Ge bonds. Transmission Electron Microscopy investigations have shown important changes induced by Ge addition in the morphology and structure of Ti-Ge-N films. Electron Energy-Loss Spectrometry study revealed a significant increase of Ge content at the grain boundaries. The segregation of Ge atoms to the TiN crystallite surface appears to be responsible for limitation of crystal growth and formation of a TiGe y amorphous phase

Composition-control of magnetron-sputter-deposited (BaxSr1-x)Ti1+yO3+z thin films for voltage tunable devices

Science.gov (United States)

Im, Jaemo; Auciello, O.; Baumann, P. K.; Streiffer, S. K.; Kaufman, D. Y.; Krauss, A. R.

2000-01-01

Precise control of composition and microstructure is critical for the production of (BaxSr1-x)Ti1+yO3+z (BST) dielectric thin films with the large dependence of permittivity on electric field, low losses, and high electrical breakdown fields that are required for successful integration of BST into tunable high-frequency devices. Here, we present results on composition-microstructure-electrical property relationships for polycrystalline BST films produced by magnetron-sputter deposition, that are appropriate for microwave and millimeter-wave applications such as varactors and frequency triplers. Films with controlled compositions were grown from a stoichiometric Ba0.5Sr0.5TiO3 target by control of the background processing gas pressure. It was determined that the (Ba+Sr)/Ti ratios of these BST films could be adjusted from 0.73 to 0.98 by changing the total (Ar+O2) process pressure, while the O2/Ar ratio did not strongly affect the metal ion composition. Film crystalline structure and dielectric properties as a function of the (Ba+Sr)/Ti ratio are discussed. Optimized BST films yielded capacitors with low dielectric losses (0.0047), among the best reported for sputtered BST, while still maintaining tunabilities suitable for device applications.

Composition-control of magnetron-sputter-deposited (BaxSr1-x)Ti1+yO3+z thin films for voltage tunable devices

International Nuclear Information System (INIS)

Im, Jaemo; Auciello, O.; Baumann, P. K.; Streiffer, S. K.; Kaufman, D. Y.; Krauss, A. R.

2000-01-01

Precise control of composition and microstructure is critical for the production of (Ba x Sr 1-x )Ti 1+y O 3+z (BST) dielectric thin films with the large dependence of permittivity on electric field, low losses, and high electrical breakdown fields that are required for successful integration of BST into tunable high-frequency devices. Here, we present results on composition-microstructure-electrical property relationships for polycrystalline BST films produced by magnetron-sputter deposition, that are appropriate for microwave and millimeter-wave applications such as varactors and frequency triplers. Films with controlled compositions were grown from a stoichiometric Ba 0.5 Sr 0.5 TiO 3 target by control of the background processing gas pressure. It was determined that the (Ba+Sr)/Ti ratios of these BST films could be adjusted from 0.73 to 0.98 by changing the total (Ar+O 2 ) process pressure, while the O 2 /Ar ratio did not strongly affect the metal ion composition. Film crystalline structure and dielectric properties as a function of the (Ba+Sr)/Ti ratio are discussed. Optimized BST films yielded capacitors with low dielectric losses (0.0047), among the best reported for sputtered BST, while still maintaining tunabilities suitable for device applications. (c) 2000 American Institute of Physics

Preparation and switching kinetics of Pb(Zr, Ti)O3 thin films deposited by reactive sputtering

International Nuclear Information System (INIS)

Hase, Takashi; Shiosaki, Tadashi

1991-01-01

Ferroelectric Pb(Zr, Ti)O 3 [PZT] thin films have been prepared on Pt/Ti/SiO 2 /Si and Pt/SiO 2 /Si substrates using the reactive sputtering method with a metal composite target. The (111)-oriented PZT (80/20) thin films with a perovskite structure have been obtained at a substrate temperature of 595degC on highly (111)-oriented Pt films formed on SiO 2 /Si substrates. When an 8 V pulse sequence was applied to a 265 nm-thick film with an electrode area of 50 x 50 μm 2 , the switching time and the switched charge density measured were 20 ns and 10 μC/cm 2 , respectively. The switching time was strongly dependent on the electrode area. (author)

Characterization and temperature controlling property of TiAlN coatings deposited by reactive magnetron co-sputtering

Energy Technology Data Exchange (ETDEWEB)

Chen, J.T. [School of Physical Science and Technology, Lanzhou University, Lanzhou 730000 (China); Wang, J. [School of Physical Science and Technology, Lanzhou University, Lanzhou 730000 (China); National Key Laboratory of Surface Engineering, Lanzhou Institute of Physics, Lanzhou 730000 (China); Zhang, F.; Zhang, G.A.; Fan, X.Y.; Wu, Z.G. [School of Physical Science and Technology, Lanzhou University, Lanzhou 730000 (China); Yan, P.X. [School of Physical Science and Technology, Lanzhou University, Lanzhou 730000 (China); State Key Laboratory of Solid Lubrication, Lanzhou Institute Chemical and Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)], E-mail: pxyan@lzu.edu.cn

2009-03-20

Titanium aluminum nitride (TiAlN) ternary coating is a potential material which is expected to be applied on satellite for thermal controlling. In order to investigate thermal controlling property, TiAlN coatings were deposited on Si wafers with different N{sub 2} and Ar flux ratio by reactive magnetron co-sputtering. The structure, morphology, chemical composition and optical reflectance are investigated by X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), atom force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and spectrophotometer, respectively. The orientation of the coatings depends on the N{sub 2}/Ar flux ratio. The coatings deposited with N{sub 2}/Ar ratio of 10, 30 and 60% show the cubic-TiN [2 2 0] preferred orientation and the coating deposited with N{sub 2}/Ar ratio of 100% exhibits the phase of hexagonal-AlN and cubic-TiN. The surface of the coatings becomes more compact and smoother with the N{sub 2}/Ar ratios increase. XPS spectrum indicates that the oxides (TiO{sub 2} and Al{sub 2}O{sub 3}), oxynitride (TiN{sub x}O{sub y}) and nitrides (TiN and AlN{sub x}) appear at the surface of the coatings. Ignoring internal power, the optimum equilibrium temperature of TiAlN coatings is 18 deg. C and the equilibrium temperature after heat-treated has slight change, which provides the prospective application on thermal controlling.

The Photocatalytic Activity and Compact Layer Characteristics of TiO2 Films Prepared Using Radio Frequency Magnetron Sputtering

Directory of Open Access Journals (Sweden)

H. C. Chang

2014-01-01

Full Text Available TiO2 compact layers are used in dye-sensitized solar cells (DSSCs to prevent charge recombination between the electrolyte and the transparent conductive substrate (indium tin oxide, ITO; fluorine-doped tin oxide, FTO. Thin TiO2 compact layers are deposited onto ITO/glass by means of radio frequency (rf magnetron sputtering, using deposition parameters that ensure greater photocatalytic activity and increased DSSC conversion efficiency. The photoinduced decomposition of methylene blue (MB and the photoinduced hydrophilicity of the TiO2 thin films are also investigated. The photocatalytic performance characteristics for the deposition of TiO2 films are improved by using the Grey-Taguchi method. The average transmittance in the visible region exceeds 85% for all samples. The XRD patterns of the TiO2 films, for sol-gel with spin coating of porous TiO2/TiO2 compact/ITO/glass, show a good crystalline structure. In contrast, without the TiO2 compact layer (only porous TiO2, the peak intensity of the anatase (101 plane in the XRD patterns for the TiO2 film has a lower value, which demonstrates inferior crystalline quality. With a TiO2 compact layer to prevent charge recombination, a higher short-circuit current density is obtained. The DSSC with the FTO/glass and Pt counter electrode demonstrates the energy conversion efficiency increased.

Fabrication and characterization of anatase/rutile–TiO2 thin films by magnetron sputtering: a review

Directory of Open Access Journals (Sweden)

Sakae Tanemura, Lei Miao, Wilfried Wunderlich, Masaki Tanemura, Yukimasa Mori, Shoichi Toh and Kenji Kaneko

2005-01-01

Full Text Available This review article summarizes briefly some important achievements of our recent reserach on anatase and/or rutile TiO2 thin films, fabricated by helicon RF magnetron sputtering, with good crystal quality and high density, and gives the-state-of-the-art of the knowledge on systematic interrelationship for fabrication conditions, crystal structure, composition, optical properties, and bactericidal abilities, and on the effective surface treatment to improve the optical reactivity of the obtained films.

Properties of reactively radio frequency-magnetron sputtered (Zr,Sn)TiO4 dielectric films

International Nuclear Information System (INIS)

Huang, C.-L.; Hsu, C.-H.

2004-01-01

Zirconium tin titanium oxide doped 1 wt % ZnO thin films on n-type Si substrate were deposited by rf magnetron sputtering at a fixed rf power of 350 W with various argon-oxygen (Ar/O 2 ) mixture and different substrate temperatures. Electrical properties and microstructures of ZnO-doped (Zr 0.8 Sn 0.2 )TiO 4 thin films prepared by rf magnetron sputtering on n-type Si(100) substrates at different Ar/O 2 ratios and substrate temperatures have been investigated. The surface structural and morphological characteristics analyzed by x-ray diffraction, scanning electron microscopy, and atomic force microscope were sensitive to the deposition conditions, such as Ar/O 2 ratio (100/0-80/20) and substrate temperature (350 deg. C-450 deg. C). The selected-area diffraction pattern showed that the deposited films exhibited a polycrystalline microstructure. All films exhibited ZST (111) orientation perpendicular to the substrate surface and the grain size as well as the deposition rate of the films increased with the increase of both the Ar partial pressure and the substrate temperature. At a Ar/O 2 ratio of 100/0, rf power level of 350 W and substrate temperature of 450 deg. C, the Zr 0.8 Sn 0.2 TiO 4 films with 6.44 μm thickness possess a dielectric constant of 42 (at 10 MHz), a dissipation factor of 0.065 (at 10 MHz), and a leakage current density of 2x10 -7 A/cm 2 at an electrical field of 1 kV/cm

Microstructural control of TiC/a-C nanocomposite coatings with pulsed magnetron sputtering

International Nuclear Information System (INIS)

Pei, Y.T.; Chen, C.Q.; Shaha, K.P.; De Hosson, J.Th.M.; Bradley, J.W.; Voronin, S.A.; Cada, M.

2008-01-01

In this paper, we report some striking results on the microstructural control of TiC/a-C nanocomposite coatings with pulsed direct current (DC) magnetron sputtering. The interface morphology and microstructure evolution as a function of pulse frequency and duty cycle were scrutinized using atomic force microscopy, scanning electron microscopy and high-resolution transmission electron microscopy techniques. It is shown that, with increasing pulse frequency, the nanocomposite coatings exhibit evolutions in morphology of the growing interface from rough to smooth and in the microstructure from strongly columnar to fully columnar-free. In addition, the smoothly growing interface favors the formation of a tailor-made multilayered nanocomposite structure. The fundamental mechanisms are analyzed with the assistance of plasma diagnostic experiments. Ion mass/energy spectrometry measurements reveal that, depending on the frequency and duty cycle of DC pulses, pulsing of the magnetrons can control the flux and energy distribution of Ar + ions over a very broad range for concurrent impingement on the growing interface of deposited coatings, in comparison with DC sputtering. The significantly enhanced energy flux density is thought to be responsible for the 'adatom transfer' in interface smoothening and thus the restraint of columnar growth

Effect of deposition temperature of TiO2 on the piezoelectric property of PbTiO3 film grown by PbO gas phase reaction sputtering

International Nuclear Information System (INIS)

Kim, Jiyoon; Kim, Yunseok; Park, Moonkyu; No, Kwangsoo; Hong, Seungbum; Buehlmann, Simon; Kim, Yong Kwan

2010-01-01

A 17 nm thick PbTiO 3 (PTO) films were fabricated via PbO gas phase reaction with TiO 2 starting layer in a sputtering chamber. The influence of deposition temperature of TiO 2 on the piezoelectric properties of PTO thin films was investigated. The remnant piezoresponse of PTO films nonlinearly increased as a function of TiO 2 deposition temperature, which is correlated with the increase in average grain diameter of PTO film. As grain size increases, the restriction on remnant piezoresponse imposed by the grain boundary via coupling between local strain and polarization becomes less pronounced, which results in the increase in remnant piezoresponse. Furthermore, we found that the vertical shift in piezoresponse hysteresis loops is closely related to the residual stress state. A strong correlation between the negative vertical shift and the residual tensile stress reveals that residual stress on the resulting PTO film contributed to the asymmetric piezoelectric property.

Low temperature rf sputtering deposition of (Ba, Sr) TiO3 thin film with crystallization enhancement by rf power supplied to the substrate

International Nuclear Information System (INIS)

Yoshimaru, Masaki; Takehiro, Shinobu; Abe, Kazuhide; Onoda, Hiroshi

2005-01-01

The (Ba, Sr) TiO 3 thin film deposited by radio frequency (rf) sputtering requires a high deposition temperature near 500 deg. C to realize a high relative dielectric constant over of 300. For example, the film deposited at 330 deg. C contains an amorphous phase and shows a low relative dielectric constant of less than 100. We found that rf power supplied not only to the (Ba, Sr) TiO 3 sputtering target, but also to the substrate during the initial step of film deposition, enhanced the crystallization of the (Ba, Sr) TiO 3 film drastically and realized a high dielectric constant of the film even at low deposition temperatures near 300 deg. C. The 50-nm-thick film with only a 10 nm initial layer deposited with the substrate rf biasing is crystallized completely and shows a high relative dielectric constant of 380 at the deposition temperature of 330 deg. C. The (Ba, Sr) TiO 3 film deposited at higher temperatures (upwards of 400 deg. C) shows preferred orientation, while the film deposited at 330 deg. C with the 10 nm initial layer shows a preferred orientation on a -oriented ruthenium electrode. The unit cell of (Ba, Sr) TiO 3 (111) plane is similar to that of ruthenium (001) plane. We conclude that the rf power supplied to the substrate causes ion bombardments on the (Ba, Sr) TiO 3 film surface, which assists the quasiepitaxial growth of (Ba, Sr) TiO 3 film on the ruthenium electrode at low temperatures of less than 400 deg. C

Low temperature rf sputtering deposition of (Ba, Sr) TiO3 thin film with crystallization enhancement by rf power supplied to the substrate

Science.gov (United States)

Yoshimaru, Masaki; Takehiro, Shinobu; Abe, Kazuhide; Onoda, Hiroshi

2005-05-01

The (Ba, Sr) TiO3 thin film deposited by radio frequency (rf) sputtering requires a high deposition temperature near 500 °C to realize a high relative dielectric constant over of 300. For example, the film deposited at 330 °C contains an amorphous phase and shows a low relative dielectric constant of less than 100. We found that rf power supplied not only to the (Ba, Sr) TiO3 sputtering target, but also to the substrate during the initial step of film deposition, enhanced the crystallization of the (Ba, Sr) TiO3 film drastically and realized a high dielectric constant of the film even at low deposition temperatures near 300 °C. The 50-nm-thick film with only a 10 nm initial layer deposited with the substrate rf biasing is crystallized completely and shows a high relative dielectric constant of 380 at the deposition temperature of 330 °C. The (Ba, Sr) TiO3 film deposited at higher temperatures (upwards of 400 °C) shows preferred orientation, while the film deposited at 330 °C with the 10 nm initial layer shows a preferred orientation on a -oriented ruthenium electrode. The unit cell of (Ba, Sr) TiO3 (111) plane is similar to that of ruthenium (001) plane. We conclude that the rf power supplied to the substrate causes ion bombardments on the (Ba, Sr) TiO3 film surface, which assists the quasiepitaxial growth of (Ba, Sr) TiO3 film on the ruthenium electrode at low temperatures of less than 400 °C.

Effect of Oxygen Partial Pressure on the Electrical and Optical Properties of DC Magnetron Sputtered Amorphous TiO2 Films

OpenAIRE

Chandra Sekhar, M.; Kondaiah, P.; Radha Krishna, B.; Uthanna, S.

2013-01-01

Titanium dioxide (TiO2) thin films were deposited on p-Si (100) and Corning glass substrates held at room temperature by DC magnetron sputtering at different oxygen partial pressures in the range 9 × 10−3–9 × 10−2 Pa. The influence of oxygen partial pressure on the structural, electrical, and optical properties of the deposited films was systematically studied. XPS studies confirmed that the film formed at an oxygen partial pressure of 6×10−2 Pa was nearly stoichiometric. TiO2 films formed at...

Photoluminescence study of trap-state defect on TiO2 thin films at different substrate temperature via RF magnetron sputtering

Science.gov (United States)

Abdullah, S. A.; Sahdan, M. Z.; Nafarizal, N.; Saim, H.; Bakri, A. S.; Cik Rohaida, C. H.; Adriyanto, F.; Sari, Y.

2018-04-01

This paper highlights the defect levels using photoluminescence spectroscopy of TiO2 thin films. The TiO2 were deposited by Magnetron Sputtering system with 200, 300, 400, and 500 °C substrate temperature on microscope glass substrate. The PL result shows profound effect of various substrate temperatures to defect levels of oxygen vacancies and Ti3+ at titanium interstitial site. Increasing temperature would minimize the oxygen vacancy defect, however Ti3+ shows otherwise. Green region of PL consist of trapped hole for oxygen vacancy, while red region of PL is trapped electron associated to structural defect Ti3+. Green PL is dominant peak at temperature 200 °C, indicating that oxygen vacancy is the main defect at this temperature. However, PL peak shows slightly same value for others samples indicating that the temperature did not give high influence to other level of defect after 200 °C.

Dye sensitized solar cell of TiO{sub 2} nanoparticle/nanorod composites prepared via low-temperature synthesis in oleic acid

Energy Technology Data Exchange (ETDEWEB)

Saji, Viswanathan S. [Department of Printed Electronics Engineering, Sunchon National University, Chonnam 540-742 (Korea, Republic of); Pyo, Myoungho, E-mail: mho@sunchon.ac.k [Department of Printed Electronics Engineering, Sunchon National University, Chonnam 540-742 (Korea, Republic of)

2010-09-01

Titania (TiO{sub 2}) nanorods (NRs) and nanoparticles (NPs) were synthesized using oleic acid as a surfactant and employed as photoanodes for dye sensitized solar cell (DSSC) fabrication. The synthesized NRs and NPs were characterized using transmission electron microscopy and X-ray diffraction. The photovoltaic performances were compared between NRs, NPs, and their composites. The results showed that the power conversion efficiencies ({eta}) of the composites depend on the relative compositions of NRs and NPs in photoanodes, reaching the greatest at 10% NR content. {eta} of the pure NRs DSSC was lower than that of the NPs DSSC. Electrochemical impedance spectroscopy revealed that the highest {eta} at 10% NRs is mainly due to reduced charge transport resistance at the TiO{sub 2}/dye/electrolyte interface and electrolyte diffusion resistance, overcoming the reduction of the number of adsorbed dye molecules.

Influence of reactive sputtering process parameters on the structure and properties of TiO{sub 2} thin films

Energy Technology Data Exchange (ETDEWEB)

El-Hamshary, Azza Amin

2011-07-11

In this work, an atomistic understanding of the growth of TiO{sub 2} thin films under the influence of various sputtering process parameters has been developed. It has been demonstrated that tailoring the structure of the reactively sputtered TiO{sub 2} thin films is possible by controlling the sputtering process parameters. Different sputtering techniques like dcMS, IBAS and HiPIMS have been utilized to fabricate TiO{sub 2} thin films. These films exhibit two crystalline structures, namely anatase and rutile. Sample preparation has been performed at different conditions, varying e.g. energetic bombardment, oxygen partial pressure and film thickness. It has been found that the formation of each phase is governed by specific parameters. For instance, energetic bombardment promotes the growth of the rutile structure. On the other hand, the growth of the anatase phase profits from the absence or very weak ion bombardment. Additionally, the anatase phase was often found for growth at high oxygen partial pressure or for thick films, whereas a rutile structure was formed otherwise. Additional substrate heating was also found to support the formation of the anatase phase. It has been demonstrated that energetic bombardment plays a dominant role in the structure formation. It has been proven that the bombardment of the growing film with highly energetic negative oxygen ions inherent in the sputtering process promotes the growth of the rutile structure. This has been observed by an investigation of the sample profile utilizing new and aged targets, since the distribution of oxygen ion bombardment along the substrate depends on the age of the target. Further support was found from investigating films grown in a HiPIMS process, where the negative oxygen ions with high energies are the dominant species governing structure formation. Furthermore, pure rutile films have also been grown under additional ion bombardment in an ion-assisted DC sputtering process. These results also

Magnetoresistance and anomalous Hall effect of reactive sputtered polycrystalline Ti1 - XCrxN films

KAUST Repository

Duan, Xiaofei

2013-09-01

The reactive-sputtered polycrystalline Ti1 - xCrxN films with 0.17 ≤ x ≤ 0.51 are ferromagnetic and at x = 0.47 the Curie temperature TC shows a maximum of ~ 120 K. The films are metallic at 0 ≤ x ≤ 0.47, while the films with x = 0.51 and 0.78 are semiconducting-like. The upturn of resistivity below 70 K observed in the films with 0.10 ≤ x ≤ 0.47 is from the effects of the electron-electron interaction and weak localization. The negative magnetoresistance (MR) of the films with 0.10 ≤ x ≤ 0.51 is dominated by the double-exchange interaction, while at x = 0.78, MR is related to the localized magnetic moment scattering at the grain boundaries. The scaling ρxyA/n ∝ ρxx2.19 suggests that the anomalous Hall effect in the polycrystalline Ti1 - xCrxN films is scattering-independent. © 2013 Elsevier B.V. All rights reserved.

Effect of N_2 flow rate on the properties of N doped TiO_2 films deposited by DC coupled RF magnetron sputtering

International Nuclear Information System (INIS)

Peng, Shou; Yang, Yong; Li, Gang; Jiang, Jiwen; Jin, Kewu; Yao, TingTing; Zhang, Kuanxiang; Cao, Xin; Wang, Yun; Xu, Genbao

2016-01-01

N doped TiO_2 films were deposited on glass substrates at room temperature using DC coupled RF magnetron sputtering with a TiO_2 ceramic target. The influences of N_2 flow rate on the deposition rate, crystal structure, chemical composition and band gap of the deposited films were investigated by Optical profiler, X-ray diffraction, X-ray photoelectron spectroscope and ultraviolet-visible spectrophotometer. The film growth rate gradually decreased with increasing N_2 flow rate. As N_2 flow rate increased, the crystallization of the films deteriorated, and the films tended to form amorphous structure. XPS analysis revealed that N dopant atoms were added at the substitutional sites into TiO_2 lattice structure. FE-SEM results showed that the grain size of the film decreased and the crystallinity degraded as N_2 flow rate increases. In addition, N doping caused an obvious red shift in the optical absorption edge. - Highlights: • N doped TiO_2 films were deposited by DC coupled RF magnetron reactive sputtering. • As N_2 flow rate increases, the crystallization of the deposited films degrades. • The higher N_2 flow rate is beneficial to form more substituted N in the film. • N doping causes an obvious red shift in the absorption wavelength.

X-ray absorption near-edge structure of hexagonal ternary phases in sputter-deposited TiAlN films

Energy Technology Data Exchange (ETDEWEB)

Gago, R., E-mail: rgago@icmm.csic.es [Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Científicas, E-28049 Madrid (Spain); Soldera, F. [Department of Materials Science and Engineering, Saarland University, D-66123 Saarbruecken (Germany); Hübner, R.; Lehmann, J.; Munnik, F. [Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, D-01314 Dresden (Germany); Vázquez, L. [Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Científicas, E-28049 Madrid (Spain); Redondo-Cubero, A. [Instituto Tecnológico e Nuclear, Instituto Superior Técnico, Universidade Técnica de Lisboa, 2686-953 Sacavém (Portugal); Endrino, J.L. [Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Científicas, E-28049 Madrid (Spain); Abengoa Research S.L., c/Energía Solar 1, Palmas Altas, E-41014 Seville (Spain)

2013-06-05

Highlights: ► Growth of ternary TiAlN films with nearly single-phase wurzite structure. ► Soft X-rays XANES measurements of ternary TiAlN films with wurzite structure. ► Identification of ternary TiAlN hexagonal phases by XANES. ► Correlation of XANES measurements with reported theoretical calculations. -- Abstract: Titanium aluminium nitride (TiAlN) coatings have been grown by reactive (Ar/N{sub 2}) direct-current magnetron sputtering from a Ti{sub 50}Al{sub 50} compound target. The film composition has been quantified by ion beam analysis showing the formation of Al-rich nitrides (Ti/Al ∼ 0.3), with stoichiometric films for N{sub 2} contents in the gas mixture equal or above ∼25%. The surface morphology of the films has been imaged by atomic force microscopy, showing very smooth surfaces with roughness values below 2 nm. X-ray and electron diffraction patterns reveal that the films are nanocrystalline with a wurzite (w) structure of lattice parameters larger (∼2.5%) than those for w-AlN. The lattice expansion correlates with the Ti/Al ratio in stoichiometric films, which suggests the incorporation of Ti into w-AlN. The atomic environments around Ti, Al and N sites have been extracted from the X-ray absorption near-edge structure (XANES) by recording the Ti2p, Al1s and N1s edges, respectively. The analysis of the XANES spectral lineshape and comparison with reported theoretical calculations confirm the formation of a ternary hexagonal phase.

Transformation of hydrogen titanate nanoribbons to TiO2 nanoribbons and the influence of the transformation strategies on the photocatalytic performance

Directory of Open Access Journals (Sweden)

Melita Rutar

2015-03-01

Full Text Available The influence of the reaction conditions during the transformation of hydrogen titanate nanoribbons to TiO2 nanoribbons on the phase composition, the morphology, the appearance of the nanoribbon surfaces and their optical properties was investigated. The transformations were performed (i through a heat treatment in oxidative and reductive atmospheres in the temperature range of 400–650 °C, (ii through a hydrothermal treatment in neutral and basic environments at 160 °C, and (iii through a microwave-assisted hydrothermal treatment in a neutral environment at 200 °C. Scanning electron microscopy investigations showed that the hydrothermal processing significantly affected the nanoribbon surfaces, which became rougher, while the transformations based on calcination in either oxidative or reductive atmospheres had no effect on the morphology or on the surface appearance of the nanoribbons. The transformations performed in the reductive atmosphere, an NH3(g/Ar(g flow, and in the ammonia solution led to nitrogen doping. The nitrogen content increased with an increasing calcination temperature, as was determined by X-ray photoelectron spectroscopy. According to electron paramagnetic resonance measurements the calcination in the reductive atmosphere also resulted in a partial reduction of Ti4+ to Ti3+. The photocatalytic performance of the derived TiO2 NRs was estimated on the basis of the photocatalytic oxidation of isopropanol. After calcinating in air, the photocatalytic performance of the investigated TiO2 NRs increased with an increased content of anatase. In contrast, the photocatalytic performance of the N-doped TiO2 NRs showed no dependence on the calcination temperature. An additional comparison showed that the N-doping significantly suppressed the photocatalytic performance of the TiO2 NRs, i.e., by 3 to almost 10 times, in comparison with the TiO2 NRs derived by calcination in air. On the other hand, the photocatalytic performance of the

Improvement of Short-Circuit Current Density in Dye-Sensitized Solar Cells Using Sputtered Nanocolumnar TiO2 Compact Layer

Directory of Open Access Journals (Sweden)

Lung-Chien Chen

2010-01-01

Full Text Available The effect of a nanocolumnar TiO2 compact layer in dye-sensitized solar cells (DSSCs was examined. Such a compact layer was sputtered on a glass substrate with an indium tin oxide (ITO film using TiO2 powder as the raw material, with a thickness of ~100 nm. The compact layer improved the short-circuit current density and the efficiency of conversion of solar energy to electricity by the DSSC by 53.37% and 59.34%, yielding values of 27.33 mA/cm2 and 9.21%, respectively. The performance was attributed to the effective electron pathways in the TiO2 compact layer, which reduced the back reaction by preventing direct contact between the redox electrolyte and the conductive substrate.

Researches on the Improvement of the Bioactivity of TiO2 Deposits, Obtained by Magnetron Sputtering - DC

Science.gov (United States)

Toma, B. F.; Baciu, R. E.; Bejinariu, C.; Cimpoieşu, N.; Ciuntu, B. M.; Toma, S. L.; Burduhos-Nergis, D. P.; Timofte, D.

2018-06-01

In this paper, layers of TiO2 were deposited, by magnetron sputtering, on a glass support. The parameters of the deposition process were kept constant except for the O2/(Ar + O2) ratio that varied on three levels. The physical and mechanical properties of the layers obtained were investigated by SEM optical microscopy, electronics, AFM and X-ray diffraction. The bioactivity of TiO2 surfaces was investigated by growing M3C3-E1 osteoblast cells produced by RIKEN Cell Bank (Japan) for a period of 5 days. The modification of the working environment in the enclosure determines both the phasic modification in the TiO2 film, respectively the amount of the anatase or rutile phase and the decrease of the average roughness of the film from 112.3nm to 56.7nm. The research has demonstrated that the finer layers with a high content of anatase promote the growth of M3C3-E1 cells.

Effect of microstructure of TiN film on properties as bipolar plate coatings in polymer electrolyte membrane fuel cell prepared by inductively coupled plasma assisted magnetron sputtering

International Nuclear Information System (INIS)

Feng, Kai; Li, Zhuguo

2013-01-01

As potential application in bipolar plate of polymer electrolyte membrane fuel cell, the microstructure, corrosion resistance and the electrical conductivity of titanium nitride (TiN) and Si doped titanium nitride (Ti 0.9 Si 0.1 N) films deposited by magnetron sputtering with different bias voltages are investigated by X-ray diffraction (XRD), scanning electron microscope (SEM), atomic force microscope (AFM), electrochemical test and four-point probe method, respectively. XRD, SEM and AFM results reveal that the texture and topography of TiN film depend on the bias voltage and incorporation of Si. When the bias voltage is − 20 V and − 30 V, the TiN and Ti 0.9 Si 0.1 N films exhibit a dense (111) plane preferred growth, denser structure and smoother surface topography. The potentiodynamic test results indicate that the TiN and Ti 0.9 Si 0.1 N films have higher chemical inertness and better corrosion resistance. The films can satisfy the requirement of current density for bipolar plate materials. Incorporation of Si element into TiN film makes the passive current density more stable. Four-point probe measurement results show that the resistivity of both TiN and Ti 0.9 Si 0.1 N films reaches minimum when the deposition bias voltage is − 20 V. - Highlights: • Dense TiN and Ti 0.9 Si 0.1 N films are deposited by magnetron sputtering. • Preferred growth orientation of TiN depends on the bias voltage and Si doping. • TiN and Ti 0.9 Si 0.1 N films have excellent corrosion resistance. • Surface conductivity of TiN and Ti 0.9 Si 0.1 N films evolves with bias voltage

Computational Fluid Dynamics (CFD) in Nuclear Reactor Safety (NRS) - Proceedings of the workshop on Experiments and CFD Code Application to Nuclear Reactor Safety (XCFD4NRS)

International Nuclear Information System (INIS)

2008-01-01

Computational Fluid Dynamics (CFD) is to an increasing extent being adopted in nuclear reactor safety analyses as a tool that enables specific safety relevant phenomena occurring in the reactor coolant system to be better described. The Committee on the Safety of Nuclear Installations (CSNI), which is responsible for the activities of the OECD Nuclear Energy Agency that support advancing the technical base of the safety of nuclear installations, has in recent years conducted an important activity in the CFD area. This activity has been carried out within the scope of the CSNI working group on the analysis and management of accidents (GAMA), and has mainly focused on the formulation of user guidelines and on the assessment and verification of CFD codes. It is in this GAMA framework that a first workshop CFD4NRS was organized and held in Garching, Germany in 2006. Following the CFD4NRS workshop, this XCFD4NRS Workshop was intended to extend the forum created for numerical analysts and experimentalists to exchange information in the field of Nuclear Reactor Safety (NRS) related activities relevant to Computational Fluid Dynamics (CFD) validation, but this time with more emphasis placed on new experimental techniques and two-phase CFD applications. The purpose of the workshop was to provide a forum for numerical analysts and experimentalists to exchange information in the field of NRS-related activities relevant to CFD validation, with the objective of providing input to GAMA CFD experts to create a practical, state-of-the-art, web-based assessment matrix on the use of CFD for NRS applications. The scope of XCFD4NRS includes: - Single-phase and two-phase CFD simulations with an emphasis on validation in areas such as: boiling flows, free-surface flows, direct contact condensation and turbulent mixing. These applications should relate to NRS-relevant issues such as: pressurized thermal shocks, critical heat flux, pool heat exchangers, boron dilution, hydrogen

Study the target effect on the structural, surface and optical properties of TiO2 thin film fabricated by RF sputtering method

Science.gov (United States)

Vyas, Sumit; Tiwary, Rohit; Shubham, Kumar; Chakrabarti, P.

2015-04-01

The effect of target (Ti metal target and TiO2 target) on Titanium Dioxide (TiO2) thin films grown on ITO coated glass substrate by RF magnetron sputtering has been investigated. A comparative study of both the films was done in respect of crystalline structure, surface morphology and optical properties by using X-ray diffractometer (XRD), Atomic Force Microscopy (AFM) studies and ellipsometric measurements. The XRD results confirmed the crystalline structure and indicated that the deposited films have the intensities of anatase phase. The surface morphology and roughness values indicated that the film using Ti metal target has a smoother surface and densely packed with grains as compared to films obtained using TiO2 target. A high transmission in the visible region, and direct band gap of 3.67 eV and 3.75 eV for films derived by using Ti metal and TiO2 target respectively and indirect bandgap of 3.39 eV for the films derived from both the targets (Ti metal and TiO2 target) were observed by the ellipsometric measurements.

Results of SSTC NRS Scientific and Technical Activities for 2014

International Nuclear Information System (INIS)

Nosovskij, A.V.; Valyigun, N.P.; Vorobej, I.I.; Kornijevska, O.S.

2015-01-01

The paper describes results of SSTC NRS scientific activities for 2014 in basic areas of activities. In particular, it addresses the development of nuclear regulatory control system, reviews, scientific and technical support to the SNRIU oversight function, research ampersand development and analytical efforts as well as scientific information and international activity. First-priority areas for SSTC NRS for the nearest years are identified

Particle-balance models for pulsed sputtering magnetrons

Science.gov (United States)

Huo, Chunqing; Lundin, D.; Gudmundsson, J. T.; Raadu, M. A.; Bradley, J. W.; Brenning, N.

2017-09-01

The time-dependent plasma discharge ionization region model (IRM) has been under continuous development during the past decade and used in several studies of the ionization region of high-power impulse magnetron sputtering (HiPIMS) discharges. In the present work, a complete description of the most recent version of the IRM is given, which includes improvements, such as allowing for returning of the working gas atoms from the target, a separate treatment of hot secondary electrons, addition of doubly charged metal ions, etc. To show the general applicability of the IRM, two different HiPIMS discharges are investigated. The first set concerns 400 μs long discharge pulses applied to an Al target in an Ar atmosphere at 1.8 Pa. The second set focuses on 100 μs long discharge pulses applied to a Ti target in an Ar atmosphere at 0.54 Pa, and explores the effects of varying the magnetic field strength. The model results show that Al2+ -ions contribute negligibly to the production of secondary electrons, while Ti2+ -ions effectively contribute to the production of secondary electrons. Similarly, the model results show that for an argon discharge with Al target the contribution of Al+-ions to the discharge current at the target surface is over 90% at 800 V. However, at 400 V the Al+-ions and Ar+-ions contribute roughly equally to the discharge current in the initial peak, while in the plateau region Ar+-ions contribute to roughly \\frac{2}{3} of the current. For high currents the discharge with Al target develops almost pure self-sputter recycling, while the discharge with Ti target exhibits close to a 50/50 combination of self-sputter recycling and working gas-recycling. For a Ti target, a self-sputter yield significantly below unity makes working gas-recycling necessary at high currents. For the discharge with Ti target, a decrease in the B-field strength, resulted in a corresponding stepwise increase in the discharge resistivity.

Hydrogen isotope behavior on Li2TiO3

International Nuclear Information System (INIS)

Olivares, Ryan; Oda, Takuji; Tanaka, Satoru; Oya, Yasuhisa; Tsuchiya, Kunihiko

2004-01-01

The surface nature of Li 2 TiO 3 and the adsorption behavior of water on Li 2 TiO 3 surface were studied by XPS/UPS and FT/IR. Preliminary experiments by Ar ion sputtering, heating and water exposure were conducted, and the following results were obtained. (1) By Ar sputtering, Li deficient surface was made, and Ti was reduced from Ti 4+ to Ti 3+ . (2) By heating sputtered samples over 573-673 K, Li emerged on the surface and Ti was re-oxidized to Ti 4+ . The surface -OH was removed. The valence band of Li 2 TiO 3 became similar to that of TiO 2 . (3) By water exposure at 623 K, H 2 O could be adsorbed dissociatively on the surface. LiOH was not formed. (4) The nature of Li 2 TiO 3 surface resembles that of TiO 2 , rather than Li 2 O. (author)

Improved irradiation tolerance of reactive gas pulse sputtered TiN coatings with a hybrid architecture of multilayered and compositionally graded structures

Science.gov (United States)

Liang, Wei; Yang, Jijun; Zhang, Feifei; Lu, Chenyang; Wang, Lumin; Liao, Jiali; Yang, Yuanyou; Liu, Ning

2018-04-01

This study investigates the improved irradiation tolerance of reactive gas pulse (RGP) sputtered TiN coatings which has hybrid architecture of multilayered and compositionally graded structures. The multilayered RGP-TiN coating is composed of hexagonal close-packed Ti phase and face-centred cubic TiN phase sublayers, where the former sublayer has a compositionally graded structure and the latter one maintains constant stoichiometric atomic ratio of Ti:N. After 100 keV He ion irradiation, the RGP-TiN coating exhibits improved irradiation resistance compared with its single layered (SL) counterpart. The size and density of He bubbles are smaller in the RGP-TiN coating than in the SL-TiN coating. The irradiation-induced surface blistering of the coatings shows a similar tendency. Meanwhile, the irradiation hardening and adhesion strength of the RGP-TiN coatings were not greatly affected by He irradiation. Moreover, the irradiation damage tolerance of the coatings can be well tuned by changing the undulation period number of N2 gas flow rate. Detailed analysis suggested that this improved irradiation tolerance could be related to the combined contribution of the multilayered and compositionally graded structures.

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.

Preparation and switching kinetics of Pb(Zr, Ti)O sub 3 thin films deposited by reactive sputtering

Energy Technology Data Exchange (ETDEWEB)

Hase, Takashi; Shiosaki, Tadashi [Kyoto Univ. (Japan). Faculty of Engineering

1991-09-01

Ferroelectric Pb(Zr, Ti)O{sub 3} (PZT) thin films have been prepared on Pt/Ti/SiO{sub 2}/Si and Pt/SiO{sub 2}/Si substrates using the reactive sputtering method with a metal composite target. The (111)-oriented PZT (80/20) thin films with a perovskite structure have been obtained at a substrate temperature of 595degC on highly (111)-oriented Pt films formed on SiO{sub 2}/Si substrates. When an 8 V pulse sequence was applied to a 265 nm-thick film with an electrode area of 50 x 50 {mu}m{sup 2}, the switching time and the switched charge density measured were 20 ns and 10 {mu}C/cm{sup 2}, respectively. The switching time was strongly dependent on the electrode area. (author).

Faraday screen sputtering on TPX

International Nuclear Information System (INIS)

Ehst, D.A.

1994-12-01

The TPX design stipulates that the ion-cyclotron resonance frequency (ICRF) antenna must have a Faraday screen (FS). The author considers here possible low Z coatings for the screen, as well as sputtering behavior of the Ni and Ti substrates. The theory of rf-induced sputtering has been developed, and he follows those theoretical approaches. The author's emphasis will be on both impurity generation as a possible source of increased Z eff , and also on actual erosion-lifetime of the materials under worst case conditions

In-situ co-doping of sputter-deposited TiO2:WN films for the development of photoanodes intended for visible-light electro-photocatalytic degradation of emerging pollutants

Science.gov (United States)

Delegan, N.; Pandiyan, R.; Komtchou, S.; Dirany, A.; Drogui, P.; El Khakani, M. A.

2018-05-01

We report on the magnetron sputtering deposition of in-situ codoped TiO2:WN films intended for electro-photocatalytic (EPC) applications under solar irradiation. By varying the RF-magnetron sputtering deposition parameters, we were able to tune the in-situ incorporation of both N and W dopants in the TiO2 films over a wide concentration range (i.e., 0-9 at. % for N and 0-3 at. % for W). X-ray photoelectron spectroscopy analysis revealed that both dopants are mostly of a substitutional nature. The analysis of the UV-Vis transmission spectra of the films confirmed that the optical bandgap of both TiO2:N and TiO2:WN films can be significantly narrowed (from 3.2 eV for undoped-TiO2 down to ˜2.3 eV for the doped ones) by tuning their dopant concentrations. We were thus able to pinpoint an optimal window for both dopants (N and W) where the TiO2:WN films exhibit the narrowest bandgap. Moreover, the optimal codoping conditions greatly reduce the recombination defect state density compared to the monodoped TiO2:N films. These electronically passivated TiO2:WN films are shown to be highly effective for the EPC degradation of atrazine (pesticide pollutant) under sunlight irradiation (93% atrazine degraded after only 30 min of EPC treatment). Indeed, the optimally codoped TiO2:WN photoanodes were found to be more efficient than both the undoped-TiO2 and equally photosensitized TiO2:N photoanodes (by ˜70% and ˜25%, respectively) under AM1.5 irradiation.

Magnetron sputtered Cu{sub 3}N/NiTiCu shape memory thin film heterostructures for MEMS applications

Energy Technology Data Exchange (ETDEWEB)

Kaur, Navjot; Choudhary, Nitin [Indian Institute of Technology Roorkee, Roorkee, Functional Nanomaterials Research Lab, Department of Physics and Centre of Nanotechnology (India); Goyal, Rajendra N. [Indian Institute of Technology, Roorkee, Department of Chemistry (India); Viladkar, S. [Indian Institute of Technology Roorkee, Roorkee, Functional Nanomaterials Research Lab, Department of Physics and Centre of Nanotechnology (India); Matai, I.; Gopinath, P. [Indian Institute of Technology, Roorkee, Centre for Nanotechnology (India); Chockalingam, S. [Indian Institute of Technology, Guwahati, Department of Biotechnology (India); Kaur, Davinder, E-mail: dkaurfph@iitr.ernet.in [Indian Institute of Technology Roorkee, Roorkee, Functional Nanomaterials Research Lab, Department of Physics and Centre of Nanotechnology (India)

2013-03-15

In the present study, for the first time, Cu{sub 3}N/NiTiCu/Si heterostructures were successfully grown using magnetron sputtering technique. Nanocrystalline copper nitride (Cu{sub 3}N with thickness {approx}200 nm) thin films and copper nanodots were subsequently deposited on the surface of 2-{mu}m-thick NiTiCu shape memory thin films in order to improve the surface corrosion and nickel release properties of NiTiCu thin films. Interestingly, the phase transformation from martensite phase to austenite phase has been observed in Cu{sub 3}N/NiTiCu heterostructures with corresponding change in texture and surface morphology of top Cu{sub 3}N films. Field emission scanning electron microscopy and atomic force microscope images of the heterostructures reveals the formation of 20-nm-sized copper nanodots on NiTiCu surface at higher deposition temperature (450 Degree-Sign C) of Cu{sub 3}N. Cu{sub 3}N passivated NiTiCu films possess low corrosion current density with higher corrosion potential and, therefore, better corrosion resistance as compared to pure NiTiCu films. The concentration of Ni released from the Cu{sub 3}N/NiTiCu samples was observed to be much less than that of pure NiTiCu film. It can be reduced to the factor of about one-ninth after the surface passivation resulting in smooth, homogeneous and highly corrosion resistant surface. The antibacterial and cytotoxicity of pure and Cu{sub 3}N coated NiTiCu thin films were investigated through green fluorescent protein expressing E. coli bacteria and human embryonic kidney cells. The results show the strong antibacterial property and non cytotoxicity of Cu{sub 3}N/NiTiCu heterostructure. This work is of immense technological importance due to variety of BioMEMS applications.

Stoichiometry and phase purity control of radio frequency magnetron sputter deposited Ba0.45Sr0.55TiO3 thin films for tunable devices

Science.gov (United States)

Alema, Fikadu; Reinholz, Aaron; Pokhodnya, Konstantin

2013-11-01

The systematic study of the oxygen partial pressure (OPP) and total chamber gas pressure (TGP) effects on the stoichiometry and crystal structure of rf sputtered Ba0.45Sr0.55TiO3 (BST) films and their phase purity allowed identifying close to optimal sputtering parameters for BST single phase polycrystalline film. The film with a Ba/Sr ratio equal to that of the source target and (Ba + Sr)/Ti ratio close to unity demonstrated the enhanced permittivity value of 553 and tunability of 69%. It was confirmed that the increase of TGP enables better match of the film and target stoichiometry. However, using O2/Ar ratio as a parameter should be utilized cautiously since exceeding a threshold OPP (2 mTorr in our case) may facilitate secondary phase formation. Relatively large dielectric losses were observed in both films sputtered at high (30 mTorr) and low (5 mTor) TGPs. The presence of oxygen vacancies was identified as a probable cause of losses, which is indirectly confirmed by the deviation of the film lattice constant from that of the bulk target.

Structural and electrical properties of sputtering power and gas pressure on Ti-dope In2O3 transparent conductive films by RF magnetron sputtering

Science.gov (United States)

Chaoumead, Accarat; Joo, Bong-Hyun; Kwak, Dong-Joo; Sung, Youl-Moon

2013-06-01

Transparent conductive titanium-doped indium oxide (ITiO) films were deposited on Corning glass substrates by RF magnetron sputtering method. The effects of RF sputtering power and Ar gas pressure on the structural and electrical properties of the films were investigated experimentally, using a 2.5 wt% TiO2-doped In2O3 target. The deposition rate was in the range of around 20-60 nm/min under the experimental conditions of 5-20 mTorr of gas pressure and 220-350 W of RF power. The lowest resistivity of 1.2 × 10-4 Ω cm, the average optical transmittance of 75%, the high hall mobility of 47.03 cm2/V s and the relatively low carrier concentration of 1.15E+21 cm-3 were obtained for the ITiO film, prepared at RF power of 300 W and Ar gas pressure of 15 mTorr. This resistivity of 1.2 × 10-4 Ω cm is low enough as a transparent conducting layer in various electro-optical devices and it is comparable with that of ITO or ZnO:Al conducting layer.

Electrochemical behavior of single layer CrN, TiN, TiAlN coatings and nanolayered TiAlN/CrN multilayer coatings prepared by reactive direct current magnetron sputtering

International Nuclear Information System (INIS)

William Grips, V.K.; Barshilia, Harish C.; Selvi, V. Ezhil; Kalavati; Rajam, K.S.

2006-01-01

The corrosion behaviors of single layer TiN, CrN, TiAlN and multilayer TiAlN/CrN coatings, deposited on steel substrate using a multi-target reactive direct current magnetron sputtering process, were studied in 3.5% NaCl solution by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The total thickness of the coatings was about 1.5 μm. About 0.5 μm thick chromium interlayer was used for improved adhesion of the coatings. The potentiodynamic polarization measurements showed that for all the coatings the corrosion potential shifted to higher values as compared to the uncoated substrate. Similarly, the corrosion current density decreased for coated samples, indicating better corrosion resistance of the coated samples. The multilayer coatings of TiAlN/CrN exhibited superior corrosion behavior as compared to the single layer coatings. The Nyquist and the Bode plots obtained from the EIS measurements were fitted by appropriate equivalent circuits to calculate the pore resistance, the charge transfer resistance and the capacitance. These studies revealed that the pore resistance was lowest for TiN coatings, which increased for TiAlN coatings. TiAlN/CrN multilayer coatings exhibited highest pore resistance. No significant change in the capacitive behavior of the coatings was observed, suggesting minimal morphological changes as a result of immersion in the electrolyte. This could be attributed to shorter immersion durations. These studies were confirmed by examining the corroded samples under scanning electron microscope. Preliminary experiments conducted with additional interlayer of electroless nickel (5.0 μm thick) have shown significant improvement in the corrosion resistance of the coatings

Crystallographic Structure Analysis of a Ti-Ta Thin Film Materials Library Fabricated by Combinatorial Magnetron Sputtering.

Science.gov (United States)

Kadletz, Peter M; Motemani, Yahya; Iannotta, Joy; Salomon, Steffen; Khare, Chinmay; Grossmann, Lukas; Maier, Hans Jürgen; Ludwig, Alfred; Schmahl, Wolfgang W

2018-03-12

Ti-Ta thin films exhibit properties that are of interest for applications as microactuators and as biomedical implants. A Ti-Ta thin film materials library was deposited at T = 25 °C by magnetron sputtering employing the combinatorial approach, which led to a compositional range of Ti 87 Ta 13 to Ti 14 Ta 86 . Subsequent high-throughput characterization methods permitted a quick and comprehensive study of the crystallographic, microstructural, and morphological properties, which strongly depend on the chemical composition. SEM investigation revealed a columnar morphology having pyramidal, sharp tips with coarser columns in the Ti-rich and finer columns in the Ta-rich region. By grazing incidence X-ray diffraction four phases were identified, from Ta-lean to Ta-rich: ω phase, α″ martensite, β phase, and a tetragonal Ta-rich phase (Ta (tetr) ). The crystal structure and microstructure were analyzed by Rietveld refinement and clear trends could be determined as a function of Ta-content. The lattice correspondences between β as the parent phase and α″ and ω as derivative phases were expressed in matrix form. The β ⇌ α″ phase transition shows a discontinuity at the composition where the martensitic transformation temperatures fall below room temperature (between 34 and 38 at. % Ta) rendering it first order and confirming its martensitic nature. A short study of the α″ martensite employing the Landau theory is included for a mathematical quantification of the spontaneous lattice strain at room temperature (ϵ̂ max = 22.4(6) % for pure Ti). Martensitic properties of Ti-Ta are beneficial for the development of high-temperature actuators with actuation response at transformation temperatures higher than 100 °C.

Effect of the degree of high power impulse magnetron sputtering utilisation on the structure and properties of TiN films

Energy Technology Data Exchange (ETDEWEB)

Hovsepian, Papken Eh.; Sugumaran, Arunprabhu A., E-mail: Arunprabhu.ArunachalamSugumaran@student.shu.ac.uk; Purandare, Yashodhan; Loch, Daniel A.L.; Ehiasarian, Arutiun P.

2014-07-01

TiN films were deposited using high power impulse magnetron sputtering (HIPIMS) enabled four cathode industrial size coating system equipped with HIPIMS power supplies. The standard version of this system allows control over the ion bombardment during coating growth by varying the strength of the electromagnetic field of the unbalancing coils and bias voltage applied to the substrate. The coatings were produced in different coating growth conditions achieved in combined HIPIMS — direct current (dc) unbalanced magnetron sputtering (HIPIMS/UBM) processes where HIPIMS was used as an additional tool to manipulate the ionisation degree in the plasma. Four cathode combinations were explored with increasing contribution of HIPIMS namely 4UBM (pure UBM), 1HIPIMS + 3UBM, 2HIPIMS + 2UBM and 2HIPIMS (pure HIPIMS) to deposit TiN coatings. Optical emission spectroscopy (OES) measurements were carried out to examine the plasma generated by the various combinations of HIPIMS and UBM cathodes. The micro-structural study was done by scanning electron microscopy (SEM). X-ray diffraction (XRD) technique was used to calculate the residual stress and texture parameter. It has been revealed that the residual stress can be controlled in a wide range from − 0.22 GPa to − 11.67 GPa by intelligent selection of the degree of HIPIMS utilisation, strength of the electromagnetic field of the unbalancing coils and the bias voltage applied to the substrate while maintaining the stoichiometry of the coatings. The effect of the degree of HIPIMS utilisation on the microstructure, texture and residual stress is discussed. Combining HIPIMS with dc-UBM sputtering is also seen as an effective tool for improving the productivity of the deposition process. - Highlights: • High {Ti"1"+} in the plasma with increasing number of HIPIMS sources • Residual stress can be manipulated in a wide range. • Texture can be altered. • The 2HIPIMS + 2UBM combination appears to be the most advantageous.

Development of Dye-Sensitized Solar Cells with Sputtered N-Doped TiO2 Thin Films: From Modeling the Growth Mechanism of the Films to Fabrication of the Solar Cells

Directory of Open Access Journals (Sweden)

D. A. Duarte

2014-01-01

Full Text Available In this paper, nitrogen-doped TiO2 thin films were deposited by DC reactive sputtering at different doping levels for the development of dye-sensitized solar cells. The mechanism of film growth during the sputtering process and the effect of the nitrogen doping on the structural, optical, morphological, chemical, and electronic properties of the TiO2 were investigated by numerical modeling and experimental methods. The influence of the nitrogen doping on the working principle of the prototypes was investigated by current-voltage relations measured under illuminated and dark conditions. The results indicate that, during the film deposition, the control of the oxidation processes of the nitride layers plays a fundamental role for an effective incorporation of substitutional nitrogen in the film structure and cells built with nitrogen-doped TiO2 have higher short-circuit photocurrent in relation to that obtained with conventional DSSCs. On the other hand, DSSCs built with nondoped TiO2 have higher open-circuit voltage. These experimental observations indicate that the incorporation of nitrogen in the TiO2 lattice increases simultaneously the processes of generation and destruction of electric current.

Studies of thin films of Ti- Zr -V as non-evaporable getter films prepared by RF sputtering

International Nuclear Information System (INIS)

Gupta, Nidhi; Jagannath,; Sharma, R. K.; Gadkari, S. C.; Muthe, K. P.; Mukundhan, R.; Gupta, S. K.

2013-01-01

Non-Evaporable Getter (NEG) films of the Ti-Zr-V prepared on stainless steel substrates by Radio Frequency sputtering. To observe its getter behavior at the lowest activation temperature, the sample is heated continuously at different temperatures (100°C, 150°C, 200°C and 250°C) for 2 hours. The changes of the surface chemical composition at different temperaturesare analyzed by using XPS and SEM (Scanning Electron Microscopy) techniques. The volume elemental composition of the film has been measured by energy dispersive X-ray spectroscopy (EDX). The in-situ XPS measurements of the activated getter films show the disappearance of the superficial oxide layer through the variation in the oxygen stoichiometry during thermal activation. Results of these studies show that the deposited films of Ti-Zr-V could be used as NEG to produce extreme high vacuum.

Relationship Between Crystalline Structure and Hardness of Ti-Si-N-O Coatings Fabricated by dc Sputtering

Science.gov (United States)

García-González, Leandro; Hernández-Torres, Julián; Mendoza-Barrera, Claudia; Meléndez-Lira, Miguel; García-Ramírez, Pedro J.; Martínez-Castillo, Jaime; Sauceda, Ángel; Herrera-May, Agustin L.; Muñoz Saldaña, Juan; Espinoza-Beltrán, Francisco J.

2008-08-01

Ti-Si-N-O coatings were deposited on AISI D2 tool steel and silicon substrates by dc reactive magnetron co-sputtering using a target of Ti-Si with a constant area ratio of 0.2. The substrate temperature was 400 °C and reactive atmosphere of nitrogen and argon. For all samples, argon flow was maintained constant at 25 sccm, while the flow of the nitrogen was varied to analyze the structural changes related to chemical composition and resistivity. According to results obtained by x-ray diffraction and stoichiometry calculations by x-ray energy dispersive spectroscopy the Ti-Si-N-O coatings contain two solid solutions. The higher crystalline part corresponds to titanium oxynitrure. Hardness tests on the coatings were carried out using the indentation work model and the hardness value was determined. Finally, the values of hardness were corroborated by nanoindentation test, and values of Young’s modulus and elastic recovery were discussed. We concluded that F2TSN sample ( F Ar = 25 sccm, F N = 5 sccm, P = 200 W, and P W = 8.9 × 10-3 mbar) presented the greatest hardness and the lowest resistivity values, due to its preferential crystalline orientation.

Coating multilayer material with improved tribological properties obtained by magnetron sputtering

Science.gov (United States)

Mateescu, A. O.; Mateescu, G.; Balasoiu, M.; Pompilian, G. O.; Lungu, M.

2017-02-01

This work is based on the Patent no. RO 128094 B1, granted by the Romanian State Office for Inventions and Trademarks. The goal of the work is to obtain for investigations tribological coatings with multilayer structure with improved tribological properties, deposited by magnetron sputtering process from three materials (sputtering targets). Starting from compound chemical materials (TiC, TiB2 and WC), as sputtering targets, by deposition in argon atmosphere on polished stainless steel, we have obtained, based on the claims of the above patent, thin films of multilayer design with promising results regarding their hardness, elastic modulus, adherence, coefficient of friction and wear resistance. The sputtering process took place in a special sequence in order to ensure better tribological properties to the coating, comparing to those of the individual component materials. The tribological properties, such as the coefficient of friction, are evaluated using the tribometer test.

Co-sputtered optical films

Energy Technology Data Exchange (ETDEWEB)

Misiano, C; Simonetti, E [Selenia S.p.A., Rome (Italy)

1977-06-01

The co-sputtering of two dielectric materials with indices of refraction as widely different as possible has been investigated with the aim of obtaining both homogeneous films with an intermediate index of refraction and inhomogeneous films with predetermined profiles. An rf sputtering module is described which has been especially designed, with two separate cathodes and two independent tunable rf generators. The substrates are placed on a circular anode rotating underneath the two cathodes. So far mainly CeO/sub 2/, TiO2 and SiO/sub 2/ targets have been used. The deposition rate from each cathode and the total film thickness are determined by means of two quartz thickness monitors, sputtering compatible. Values obtained for the refractive index and optical thickness are reported, as well as repeatability, mechanical and chemical characteristics, reliability and high power optical radiation resistance. Finally, results obtained on optical components of practical interest are discussed.

Study on helium-charged titanium films deposited by DC-magnetron sputtering

International Nuclear Information System (INIS)

Shi Liqun; Jin Qinhua; Liu Chaozhuo; Xu Shilin; Zhou Zhuying

2005-01-01

Helium trapping in the Ti films deposited by DC magnetron sputtering with a He/Ar mixture was studied. He atoms with a surprisingly high concentration (He/Ti atomic ratio is as high as 56%) incorporate evenly in deposited film. The trapped amount of He can be controlled by the helium partial amount. The introduction of the helium with no extra damage (or very low damage) can be realized by choosing suitable deposition conditions. It was also found that because of the formation of nanophase Ti film a relative high He flux for bubble formation is needed and the amount of the retaining He in sputtering Ti films is much higher than that in the coarse-grain Ti films. The nanophase Ti film can accommodate larger concentration of trapped sites to He, which results in a high density and small size of the He bubbles. With increasing He irradiation flux, the grain size of Ti film decreases and the lattice spacing and width of the X-ray diffraction peak increase due to the He introduction, and the film tends to amorphous phase. (authors)

Comparison of gate dielectric plasma damage from plasma-enhanced atomic layer deposited and magnetron sputtered TiN metal gates

Energy Technology Data Exchange (ETDEWEB)

Brennan, Christopher J.; Neumann, Christopher M.; Vitale, Steven A., E-mail: steven.vitale@ll.mit.edu [Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, Massachusetts 02420 (United States)

2015-07-28

Fully depleted silicon-on-insulator transistors were fabricated using two different metal gate deposition mechanisms to compare plasma damage effects on gate oxide quality. Devices fabricated with both plasma-enhanced atomic-layer-deposited (PE-ALD) TiN gates and magnetron plasma sputtered TiN gates showed very good electrostatics and short-channel characteristics. However, the gate oxide quality was markedly better for PE-ALD TiN. A significant reduction in interface state density was inferred from capacitance-voltage measurements as well as a 1200× reduction in gate leakage current. A high-power magnetron plasma source produces a much higher energetic ion and vacuum ultra-violet (VUV) photon flux to the wafer compared to a low-power inductively coupled PE-ALD source. The ion and VUV photons produce defect states in the bulk of the gate oxide as well as at the oxide-silicon interface, causing higher leakage and potential reliability degradation.

Fabrication of TiN/AlN/TiN tunnel junctions

Energy Technology Data Exchange (ETDEWEB)

Nakayama, Takeru; Naruse, Masato; Myoren, Hiroaki; Taino, Tohru, E-mail: taino@mail.saitama-u.ac.jp

2016-11-15

Highlights: • We have fabricated TiN/AlN/TiN tunnel junctions with an epitaxial layer. • TiN and AlN films were deposited by dc and rf magnetron sputtering at ambient substrate temperatures. • The junctions have a V{sub g} = 1.1 mV, J{sub c} = 0.24 A/cm{sup 2}, R{sub sg}/R{sub n} of 7.2, and low subgap leakage current of 180 nA. - Abstract: We have fabricated TiN/AlN/TiN tunnel junctions with an epitaxial layer. The critical temperature of TiN can be changed in the range from 0.5 to 5.0 K. Therefore, it is easy to set 5.0 K as the target critical temperature. When a Superconducting Tunnel Junction (STJ) is operated as a photon detector, it is necessary to cool it to within 0.1 K of the critical temperature in consideration of the noise of the thermally stimulated currents. Because 0.3 K was desirable, as for the manufacture of general purpose photon detectors, the critical temperature 5.0 K. TiN and AlN films were deposited by dc and rf magnetron sputtering in a load-lock sputtering system at ambient substrate temperatures. The junctions have a gap voltage of V{sub g} = 1.1 mV, and critical current density of J{sub c} = 0.24 A/cm{sup 2}, and R{sub sg}/R{sub n} of 7.2, and low subgap leakage current (I{sub sub}@ 500 µV = 180 nA). We report our experiment system, the manufacture method and the junction properties in this paper.

Effect of N{sub 2} flow rate on the properties of N doped TiO{sub 2} films deposited by DC coupled RF magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Peng, Shou [State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan 430000 (China); State Key Laboratory of Advanced Technology for Float Glass, Bengbu Design & Research Institute for Glass Industry, Bengbu 233000 (China); Yang, Yong, E-mail: 88087113@163.com [State Key Laboratory of Advanced Technology for Float Glass, Bengbu Design & Research Institute for Glass Industry, Bengbu 233000 (China); Li, Gang; Jiang, Jiwen; Jin, Kewu; Yao, TingTing; Zhang, Kuanxiang [State Key Laboratory of Advanced Technology for Float Glass, Bengbu Design & Research Institute for Glass Industry, Bengbu 233000 (China); Cao, Xin [State Key Laboratory of Advanced Technology for Float Glass, Bengbu Design & Research Institute for Glass Industry, Bengbu 233000 (China); School of Materials Science and Engineering, Dalian Jiaotong University, Dalian 116000 (China); Wang, Yun; Xu, Genbao [State Key Laboratory of Advanced Technology for Float Glass, Bengbu Design & Research Institute for Glass Industry, Bengbu 233000 (China)

2016-09-05

N doped TiO{sub 2} films were deposited on glass substrates at room temperature using DC coupled RF magnetron sputtering with a TiO{sub 2} ceramic target. The influences of N{sub 2} flow rate on the deposition rate, crystal structure, chemical composition and band gap of the deposited films were investigated by Optical profiler, X-ray diffraction, X-ray photoelectron spectroscope and ultraviolet-visible spectrophotometer. The film growth rate gradually decreased with increasing N{sub 2} flow rate. As N{sub 2} flow rate increased, the crystallization of the films deteriorated, and the films tended to form amorphous structure. XPS analysis revealed that N dopant atoms were added at the substitutional sites into TiO{sub 2} lattice structure. FE-SEM results showed that the grain size of the film decreased and the crystallinity degraded as N{sub 2} flow rate increases. In addition, N doping caused an obvious red shift in the optical absorption edge. - Highlights: • N doped TiO{sub 2} films were deposited by DC coupled RF magnetron reactive sputtering. • As N{sub 2} flow rate increases, the crystallization of the deposited films degrades. • The higher N{sub 2} flow rate is beneficial to form more substituted N in the film. • N doping causes an obvious red shift in the absorption wavelength.

Growth and surface characterization of TiNbZr thin films deposited by magnetron sputtering for biomedical applications

Energy Technology Data Exchange (ETDEWEB)

Tallarico, D.A. [Federal University of Sao Carlos, Materials Science and Engineering Graduation Program, Via Washington Luis km 235, CEP 13565-905 Sao Carlos, SP (Brazil); Gobbi, A.L. [Brazilian Nanotechnology National Laboratory, Rua Giuseppe Máximo Scolfaro 10.000, CEP 13083-100 Campinas, SP (Brazil); Paulin Filho, P.I. [Federal University of Sao Carlos, Department of Materials Engineering, Via Washington Luis km 235, CEP 13565-905 Sao Carlos, SP (Brazil); Maia da Costa, M.E.H. [Pontifical Catholic University of Rio de Janeiro, Department of Physics, CEP 22451-900 Rio de Janeiro, RJ (Brazil); Nascente, P.A.P., E-mail: nascente@ufscar.br [Federal University of Sao Carlos, Department of Materials Engineering, Via Washington Luis km 235, CEP 13565-905 Sao Carlos, SP (Brazil)

2014-10-01

Low modulus of elasticity and the presence of non-toxic elements are important criteria for the development of materials for implant applications. Low modulus Ti alloys can be developed by designing β-Ti alloys containing non-toxic alloying elements such as Nb and Zr. Actually, most of the metallic implants are produced with stainless steel (SS) because it has adequate bulk properties to be used as biomaterials for orthopedic or dental implants and is less expensive than Ti and its alloys, but it is less biocompatible than them. The coating of this SS implants with Ti alloy thin films may be one alternative to improve the biomaterial properties at a relatively low cost. Sputtering is a physical deposition technique that allows the formation of nanostructured thin films. Nanostructured surfaces are interesting when it comes to the bone/implant interface due to the fact that both the surface and the bone have nanoscale particle sizes and similar mechanical properties. TiNbZr thin films were deposited on both Si(111) and stainless steel (SS) substrates. The TiNbZr/Si(111) film was used as a model system, while the TiNbZr/SS film might improve the biocompatibility and extend the life time of stainless steel implants. The morphology, chemical composition, Young's modulus, and hardness of the films were analyzed by atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDS), and nanoindentation. - Highlights: • TiNbZr thin films were deposited on Si(111) and stainless steel (SS). • Their Young's modulus differences are within 5.3% and hardness 1.7%. • TiNbZr/SS film chemical composition remained almost constant with depth. • TiNbZr films presented nanostructured grains and low roughness for substrates. • TiNbZr/SS film hardness was about 100% greater than the SS substrate hardness.

Growth and surface characterization of TiNbZr thin films deposited by magnetron sputtering for biomedical applications

International Nuclear Information System (INIS)

Tallarico, D.A.; Gobbi, A.L.; Paulin Filho, P.I.; Maia da Costa, M.E.H.; Nascente, P.A.P.

2014-01-01

Low modulus of elasticity and the presence of non-toxic elements are important criteria for the development of materials for implant applications. Low modulus Ti alloys can be developed by designing β-Ti alloys containing non-toxic alloying elements such as Nb and Zr. Actually, most of the metallic implants are produced with stainless steel (SS) because it has adequate bulk properties to be used as biomaterials for orthopedic or dental implants and is less expensive than Ti and its alloys, but it is less biocompatible than them. The coating of this SS implants with Ti alloy thin films may be one alternative to improve the biomaterial properties at a relatively low cost. Sputtering is a physical deposition technique that allows the formation of nanostructured thin films. Nanostructured surfaces are interesting when it comes to the bone/implant interface due to the fact that both the surface and the bone have nanoscale particle sizes and similar mechanical properties. TiNbZr thin films were deposited on both Si(111) and stainless steel (SS) substrates. The TiNbZr/Si(111) film was used as a model system, while the TiNbZr/SS film might improve the biocompatibility and extend the life time of stainless steel implants. The morphology, chemical composition, Young's modulus, and hardness of the films were analyzed by atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDS), and nanoindentation. - Highlights: • TiNbZr thin films were deposited on Si(111) and stainless steel (SS). • Their Young's modulus differences are within 5.3% and hardness 1.7%. • TiNbZr/SS film chemical composition remained almost constant with depth. • TiNbZr films presented nanostructured grains and low roughness for substrates. • TiNbZr/SS film hardness was about 100% greater than the SS substrate hardness

Thermal conductivity of nitride films of Ti, Cr, and W deposited by reactive magnetron sputtering

International Nuclear Information System (INIS)

Jagannadham, Kasichainula

2015-01-01

Nitride films of Ti, Cr, and W were deposited using reactive magnetron sputtering from metal targets in argon and nitrogen plasma. TiN films with (200) orientation were achieved on silicon (100) at the substrate temperature of 500 and 600 °C. The films were polycrystalline at lower temperature. An amorphous interface layer was observed between the TiN film and Si wafer deposited at 600 °C. TiN film deposited at 600 °C showed the nitrogen to Ti ratio to be near unity, but films deposited at lower temperature were nitrogen deficient. CrN film with (200) orientation and good stoichiometry was achieved at 600 °C on Si(111) wafer but the film deposited at 500 °C showed cubic CrN and hexagonal Cr 2 N phases with smaller grain size and amorphous back ground in the x-ray diffraction pattern. An amorphous interface layer was not observed in the cubic CrN film on Si(111) deposited at 600 °C. Nitride film of tungsten deposited at 600 °C on Si(100) wafer was nitrogen deficient, contained both cubic W 2 N and hexagonal WN phases with smaller grain size. Nitride films of tungsten deposited at 500 °C were nonstoichiometric and contained cubic W 2 N and unreacted W phases. There was no amorphous phase formed along the interface for the tungsten nitride film deposited at 600 °C on the Si wafer. Thermal conductivity and interface thermal conductance of all the nitride films of Ti, Cr, and W were determined by transient thermoreflectance technique. The thermal conductivity of the films as function of deposition temperature, microstructure, nitrogen stoichiometry and amorphous interaction layer at the interface was determined. Tungsten nitride film containing both cubic and hexagonal phases was found to exhibit much higher thermal conductivity and interface thermal conductance. The amorphous interface layer was found to reduce effective thermal conductivity of TiN and CrN films

Fabrication of hydroxyapatite thin films on polyetheretherketone substrates using a sputtering technique

Energy Technology Data Exchange (ETDEWEB)

Ozeki, K., E-mail: kazuhide.ozeki.365@vc.ibaraki.ac.jp [Department of Mechanical Engineering, Ibaraki University, 4-12-1, Nakanarusawa, Hitachi, Ibaraki 316-8511 (Japan); Masuzawa, T. [Department of Mechanical Engineering, Ibaraki University, 4-12-1, Nakanarusawa, Hitachi, Ibaraki 316-8511 (Japan); Aoki, H. [International Apatite Institute Co., Ltd., 2-12-9, Misaki-cho, Chiyoda-ku, Tokyo 101-0061 (Japan)

2017-03-01

Hydroxyapatite (HA) thin films were coated on a polyetheretherketone (PEEK) substrate using a sputtering technique. A thin titanium (Ti) intermediate layer was formed between the HA and the PEEK surface to improve adhesion of the HA film to the PEEK substrate. The coated films were recrystallized using a hydrothermal treatment to reduce the dissolution of the HA film. The films were then characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), and a UV-Vis spectrophotometer. A pull-out test was performed to measure the film-to-substrate adhesion strength, and an immersion test was performed in ultra-pure water. In the XRD patterns of the sputtered film with the Ti intermediate layer on the PEEK substrate, small HA peaks and large Ti peaks were observed. After the hydrothermal treatment, the intensity of the HA peaks increased. The transmittance of the HA films with 5 and 10 nm Ti intermediate layers was > 79% and 68%, respectively, in the visible light wavelength region (400–700 nm) after the hydrothermal treatment. The adhesion strength of the hydrothermally treated HA films increased with decreasing thickness of the Ti intermediate layer, and the strength reached 2.7 MPa with the 5-nm-thick Ti intermediate layer. In the immersion test, the HA film with a 5-nm-thick Ti intermediate layer without hydrothermal treatment exhibited a released Ti concentration of 42.0 ± 2.4 ppb. After hydrothermal treatment, the released Ti concentration decreased to 17.3 ± 1.1 ppb. - Highlights: • Hydroxyapatite (HA) thin films were coated on a polyetheretherketone (PEEK) substrate using a sputtering technique. • A thin Ti intermediate layer was formed between the HA and the PEEK surface to improve adhesion of the HA film. • The adhesion strength of the HA films with the Ti intermediate layer increased with decreasing thickness of the Ti layer.

Fabrication of hydroxyapatite thin films on polyetheretherketone substrates using a sputtering technique

International Nuclear Information System (INIS)

Ozeki, K.; Masuzawa, T.; Aoki, H.

2017-01-01

Hydroxyapatite (HA) thin films were coated on a polyetheretherketone (PEEK) substrate using a sputtering technique. A thin titanium (Ti) intermediate layer was formed between the HA and the PEEK surface to improve adhesion of the HA film to the PEEK substrate. The coated films were recrystallized using a hydrothermal treatment to reduce the dissolution of the HA film. The films were then characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), and a UV-Vis spectrophotometer. A pull-out test was performed to measure the film-to-substrate adhesion strength, and an immersion test was performed in ultra-pure water. In the XRD patterns of the sputtered film with the Ti intermediate layer on the PEEK substrate, small HA peaks and large Ti peaks were observed. After the hydrothermal treatment, the intensity of the HA peaks increased. The transmittance of the HA films with 5 and 10 nm Ti intermediate layers was > 79% and 68%, respectively, in the visible light wavelength region (400–700 nm) after the hydrothermal treatment. The adhesion strength of the hydrothermally treated HA films increased with decreasing thickness of the Ti intermediate layer, and the strength reached 2.7 MPa with the 5-nm-thick Ti intermediate layer. In the immersion test, the HA film with a 5-nm-thick Ti intermediate layer without hydrothermal treatment exhibited a released Ti concentration of 42.0 ± 2.4 ppb. After hydrothermal treatment, the released Ti concentration decreased to 17.3 ± 1.1 ppb. - Highlights: • Hydroxyapatite (HA) thin films were coated on a polyetheretherketone (PEEK) substrate using a sputtering technique. • A thin Ti intermediate layer was formed between the HA and the PEEK surface to improve adhesion of the HA film. • The adhesion strength of the HA films with the Ti intermediate layer increased with decreasing thickness of the Ti layer.

Near-Infrared Spectroscopy for Zeeman Spectra of Ti I in Plasma Using a Facing Target Sputtering System

Science.gov (United States)

Kobayashi, Shinji; Nishimiya, Nobuo; Suzuki, Masao

2017-10-01

The saturated absorption lines of neutral titanium were measured in the region of 9950-14380 cm-1 using a Ti:sapphire ring laser. A facing target sputtering system was used to obtain the gaseous state of a Ti I atom. The Zeeman splitting of 38 transitions was observed under the condition that the electric field component of a linearly polarized laser beam was parallel to the magnetic field. The gJ factors of the odd parity states were determined for 28 states belonging to 3d24s4p and 3d34p using those of the even parity states reported by Stachowska in 1997. The gJ factors of z5P1,2,3 levels were newly determined. gJ of y3F2, y3D2, z3P2, and z5S2 levels were refined.

Effect of Ti Doping to Maintain Structural Disorder in InOx-Based Thin-Film Transistors Fabricated by RF Magnetron Sputtering

Science.gov (United States)

Aikawa, Shinya

2017-12-01

The effect of Ti doping in an indium oxide (InOx)-based semiconductor is investigated for the thin-film transistor (TFT) property and crystal structure of the film. InOx and Ti-doped InOx (InTiOx) films deposited by RF magnetron sputtering under the same O2 partial pressure conditions were systematically compared. The TFT behavior of the InOx showed higher conductivity than that of the InTiOx and was drastically changed to metallic conduction after annealing at 150 °C. Under the annealing conditions when the electrical transition to the metallic behavior occurred, the InOx film was crystallized. The X-ray diffraction analysis revealed that the shrinkage of the In2O3 unit cell is pronounced in the case of InOx films. Thus, Ti dopants may play the role as a suppressor for shrinkage of the unit cell, i.e. maintaining neighboring In-In distances, in addition to suppression of oxygen vacancies. The In-In distance, which is related to the overlapping of In 5 s orbitals, is considered to be one of the key factor for which InOx-based materials are utilized as conducting films or semiconducting channels.

[Effect of niobium nitride on the bonding strength of titanium porcelain by magnetron sputtering].

Science.gov (United States)

Wang, Shu-shu; Zhang, La-bao; Guang, Han-bing; Zhou, Shu; Zhang, Fei-min

2010-05-01

To investigate the effect of magnetron sputtered niobium nitride (NbN) on the bonding strength of commercially pure cast titanium (Ti) and low-fusing porcelain (Ti/Vita titankeramik system). Sixty Ti specimens were randomly divided into four groups, group T1, T2, T3 and T4. All specimens of group T1 and T2 were first treated with 120 microm blasted Al2O3 particles, and then only specimens of group T2 were treated with magnetron sputtered NbN film. All specimens of group T3 and T4 were first treated with magnetron sputtered NbN film and then only specimens of group T4 were treated with 120 microm blasted Al2O3 particles. The composition of the deposits were analyzed by X-ray diffraction (XRD). A universal testing machine was used to perform the three-point bending test to evaluate the bonding strength of Ti and porcelain. The microstructure of NbN, the interface of Ti-porcelain and the fractured Ti surface were observed with scanning electron microscopy (SEM) and energy depressive spectrum (EDS), and the results were compared. The XRD results showed that the NbN deposits were cubic crystalline phases. The bonding strength of Ti and porcelain in T1 to T4 group were (27.2+/-0.8), (43.1+/-0.6), (31.4+/-1.0) and (44.9+/-0.6) MPa. These results were analyzed by one-way analysis of variance and differences between groups were compared using least significant difference test. Significant inter-group differences were found among all groups (Pporcelain, while samples treated with both Al2O3 and NbN had better bond. EDS of Ti-porcelain interface showed oxidation occurred in T1, T2 and T3, but was well controlled in T4. Magnetron sputtered NbN can prevent Ti from being oxidized, and can improve the bonding strength of Ti/Vita titankeramik system. Al2O3 blast can also improve the bonding strength of Ti/Vita titankeramik system.

Tribological Testing, Analysis and Characterization of D.C. Magnetron Sputtered Ti-Nb-N Thin Film Coatings on Stainless Steel

Science.gov (United States)

Joshi, Prathmesh

To enhance the surface properties of stainless steel, the substrate was coated with a 1μm thick coating of Ti-Nb-N by reactive DC magnetron sputtering at different N2 flow rates, substrate biasing and Nb-Ti ratio. The characterization of the coated samples was performed by the following techniques: hardness by Knoop micro-hardness tester, phase analysis by X-ray Diffraction (XRD), compositional analysis by Energy Dispersive X-ray Spectroscopy (EDS) and adhesion by scratch test. The tribology testing was performed on linearly reciprocating ball-on-plate wear testing machine and wear depth and wear volume were evaluated by white light interferometer. The micro-hardness test yielded appreciable enhancement in the surface hardness with the highest value being 1450 HK. Presence of three prominent phases namely NbN, Nb2N3 and TiN resulted from the XRD analysis. EDS analysis revealed the presence of Ti, Nb and Nitrogen. Adhesion was evaluated on the basis of critical loads for cohesive (Lc1) and adhesive (Lc2) failures with values varying between 7-12 N and 16-25 N respectively, during scratch test for coatings on SS substrates.

Nitinol: Tubing versus sputtered film - microcleanliness and corrosion behavior.

Science.gov (United States)

Wohlschlögel, Markus; Lima de Miranda, Rodrigo; Schüßler, Andreas; Quandt, Eckhard

2016-08-01

Corrosion behavior and microcleanliness of medical-device grade Nitinol tubing (Nix Ti1- x , x = 0.51; outer diameter 7 mm, wall thickness 0.5 mm), drawn from various ingot qualities, are compared to the characteristics of sputtered Nitinol film material (Nix Ti1- x , x = 0.51; thickness 50 µm). Electropolished tubing half-shell samples are tested versus as-received sputtered film samples. Inclusion size distributions are assessed using quantitative metallography and corrosion behavior is investigated by potentiodynamic polarization testing in phosphate-buffered saline at body temperature. For the sputtered film samples, the surface chemistry is additionally analyzed employing Auger Electron Spectroscopy (AES) composition-depth profiling. Results show that the fraction of breakdowns in the potentiodynamic polarization test correlates with number and size of the inclusions in the material. For the sputtered Nitinol film material no inclusions were detectable by light microscopy on the one hand and no breakdowns were found in the potentiodynamic polarization test on the other hand. As for electropolished Nitinol, the sputtered Nitinol film material reveals Nickel depletion and an Oxygen-to-Titanium intensity ratio of ∼2:1 in the surface oxide layer, as measured by AES. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1176-1181, 2016. © 2015 Wiley Periodicals, Inc.

In vitro corrosion and biocompatibility screening of sputtered Ti{sub 40}Cu{sub 36}Pd{sub 14}Zr{sub 10} thin film metallic glasses on steels

Energy Technology Data Exchange (ETDEWEB)

Subramanian, B., E-mail: subramanianb3@gmail.com

2015-02-01

The growth of multi-component thin film metallic glasses (TFMGs) of Ti{sub 40}Cu{sub 36}Pd{sub 14}Zr{sub 10} (at.%) alloys fabricated using magnetron sputtering on bioimplantable 316L stainless steel substrates has been investigated. The vapor–solid quenching during sputtering enables the amorphous phases to be formed. The amorphous films consist of a single glassy phase, as evidenced by a broad hump and no detectable crystalline peaks as observed from XRD and selective area electron diffraction (SAED) patterns. The average surface roughness (Ra) of the coated film as observed from AFM was 0.3 nm. Nanohardness of about 7.7 GPa and Young's modulus of 110 GPa were measured from nanoindentation analysis. The potentiodynamic polarization and impedance measurements showed that coated stainless steel substrates have higher corrosion resistance compared to uncoated SS substrate in simulated body fluid (SBF) solution. The cytotoxicity studies using L929 fibroblast cells showed that these coatings were non-cytotoxic in nature. The interactions between the coated surface and bacteria were investigated by agar diffusion method, solution suspension and wet interfacial contact methods. - Highlights: • Ti-based TFMG coated specimen showed superior corrosion resistance. • Ti-based TFMG coated SS 316L specimen was non-cytotoxic in nature. • Antimicrobial activity of Ti-based TFMG was noticed.

Influence of substrate on structural, morphological and optical properties of TiO2 thin films deposited by reaction magnetron sputtering

Directory of Open Access Journals (Sweden)

Xinghua Zhu

2017-12-01

Full Text Available Titanium dioxide (TiO2 films have been prepared by DC reaction magnetron sputtering technique on different substrates (glass, SiO2, platinum electrode-Pt, Silicon-Si. X-ray diffraction (XRD patterns showed that all TiO2 films were grown along the preferred orientation of (110 plane. Samples on Si and Pt substrates are almost monophasic rutile, however, samples on glass and SiO2 substrates accompanied by a weak anatase structure. Atomic force microscopy (AFM images revealed uniform grain distribution except for films on Pt substrates. Photoluminescence (PL spectra showed obvious intrinsic emission band, but films on glass was accompanied by a distinct defect luminescence region. Raman spectroscopy suggested that all samples moved to high wavenumbers and films on glass moved obviously.

Structure and mechanical properties of reactive sputter deposited TiN/TaN multilayered films

International Nuclear Information System (INIS)

Soe, W.H.; Yamamoto, R.; Ueda, H.; Shima, N.

1998-01-01

TiN/TaN multilayers were grown by reactive magnetron sputtering on WC-Co sintered hard alloy and MgO(100) single crystal substrates. Multilayer structure and composition modulation amplitudes were studied using x-ray diffraction method. Hardness and elastic modulus were measured by nanoindentation tester. For bilayer thickness (Λ) larger than 80 angstrom, hardness are lower than rule-of-mixtures value of individual single layers, and increased rapidly with decreasing Λ, peaking at hardness values ∼33% higher than that at Λ = 43 angstrom. As a result of analysis the inclination of applied load for indenter displacement on P-h curve (ΔP/Δh), this paper exhibits that the enhancement of the resistance to dislocation motion and elastic anomaly due to coherency strains are responsible for the hardness change

Functional nanostructured titanium nitride films obtained by sputtering magnetron

International Nuclear Information System (INIS)

Sanchez, O.; Hernandez-Velez, M.; Navas, D.; Auger, M.A.; Baldonedo, J.L.; Sanz, R.; Pirota, K.R.; Vazquez, M.

2006-01-01

Development of new methods in the formation of hollow structures, in particular, nanotubes and nanocages are currently generating a great interest as a consequence of the growing relevance of these nanostructures on many technological fields, ranging from optoelectronics to biotechnology. In this work, we report the formation of titanium nitride (TiN) nanotubes and nanohills via reactive sputtering magnetron processes. Anodic Alumina Membranes (AAM) were used as template substrates to grow the TiN nanostructures. The AAM were obtained through electrochemical anodization processes by using oxalic acid solutions as electrolytes. The nanotubes were produced at temperatures below 100 deg. C, and using a pure titanium (99.995%) sputtering target and nitrogen as reactive gas. The obtained TiN thin films showed surface morphologies adjusted to pore diameter and interpore distance of the substrates, as well as ordered arrays of nanotubes or nanohills depending on the sputtering and template conditions. High Resolution Scanning Electron Microscopy (HRSEM) was used to elucidate both the surface order and morphology of the different grown nanostructures. The crystalline structure of the samples was examined using X-ray Diffraction (XRD) patterns and their qualitative chemical composition by using X-ray Energy Dispersive Spectroscopy (XEDS) in a scanning electron microscopy

Tribological properties, corrosion resistance and biocompatibility of magnetron sputtered titanium-amorphous carbon coatings

International Nuclear Information System (INIS)

Dhandapani, Vishnu Shankar; Subbiah, Ramesh; Thangavel, Elangovan; Arumugam, Madhankumar; Park, Kwideok; Gasem, Zuhair M.; Veeraragavan, Veeravazhuthi; Kim, Dae-Eun

2016-01-01

Highlights: • a-C:Ti nanocomposite coatings were prepared on 316L stainless steel by using R.F. magnetron sputtering method. • Properties of the nanocomposite coatings were analyzed with respect to titanium content. • Corrosion resistance, biocompatibility and hydrophobicity of nanocomposite coating were enhanced with increasing titanium content. • Coating with 2.33 at.% titanium showed superior tribological properties compared to other coatings. - Abstract: Amorphous carbon incorporated with titanium (a-C:Ti) was coated on 316L stainless steel (SS) by magnetron sputtering technique to attain superior tribological properties, corrosion resistance and biocompatibility. The morphology, topography and functional groups of the nanostructured a-C:Ti coatings in various concentrations were analyzed using atomic force microscopy (AFM), Raman, X-Ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). Raman and XPS analyses confirmed the increase in sp"2 bonds with increasing titanium content in the a-C matrix. TEM analysis confirmed the composite nature of the coating and the presence of nanostructured TiC for Ti content of 2.33 at.%. This coating showed superior tribological properties compared to the other a-C:Ti coatings. Furthermore, electrochemical corrosion studies were performed against stimulated body fluid medium in which all the a-C:Ti coatings showed improved corrosion resistance than the pure a-C coating. Preosteoblasts proliferation and viability on the specimens were tested and the results showed that a-C:Ti coatings with relatively high Ti (3.77 at.%) content had better biocompatibility. Based on the results of this work, highly durable coatings with good biocompatibility could be achieved by incorporation of optimum amount of Ti in a-C coatings deposited on SS by magnetron sputtering technique.

Preparation and characterization of RF magnetron sputtered CuO/CaTi{sub 4}O{sub 9} thin films with enhanced third-order nonlinear optical properties

Energy Technology Data Exchange (ETDEWEB)

Yin, Congfei; Liang, Xiaojuan, E-mail: lxj6126@126.com; Hu, Guangcai; Hu, Xie; Chen, Xipeng; Li, Pengzhi; Xiang, Weidong, E-mail: xiangweidong001@126.com

2017-04-15

The titanate, is a material of interest for various energy applications, including photovoltaics, catalysts, and high-rate energy storage devices. Herein, its related materials, CuO/CaTi{sub 4}O{sub 9} [CCTO] thin films, were successfully fabricated on SrTiO{sub 3} (100) substrates by RF magnetron sputtering assisted with subsequent oxygen annealing. This obtained CCTO thin films were then systemically studied by X-ray powder diffraction (XRD), atomic force microscopy (AFM), scan electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and high-resolution transmission electron microscopy (HRTEM). It was found that CuO and CaTi{sub 4}O{sub 9} (001) particles were closely accumulated together on the surface of the substrate in the annealing process after comparing with that of the as-prepared thin film, which was verified by SEM and AFM results. Furthermore, we investigated the third-order nonlinear optical (NLO) properties of the as-prepared and annealed CCTO thin film by means of the Z-scan technique using 650 nm femtosecond laser pulse. Post-deposition oxygen annealing was found to modify the morphological characteristics of the films, resulting in enhancing their NLO properties. The observation of NLO performance of annealed CCTO thin film indicates that RF magnetron sputtering is a feasible method for the fabrication of optical thin films, which can be expanded to fabricate other NLO materials from the corresponding dispersions. Naturally, we concluded that the CCTO thin film occupy a better NLO property, and thus enlarge its application in nonlinear optics. - Highlights: • The CCTO thin film was prepared using the RF magnetron sputtering and oxygen annealing. • The film was prepared on the SrTiO{sub 3}(100) substrates with a Ca{sub 2}CuO{sub 3} target. • The oxygen annealing was found can effectively enhance the film quality and NLO property. • The film was characterized using XPS, SEM, AFM, TEM, XRD and Z-scan techniques.

Comparison of lanthanum substituted bismuth titanate (BLT) thin films deposited by sputtering and pulsed laser deposition

International Nuclear Information System (INIS)

Besland, M.P.; Djani-ait Aissa, H.; Barroy, P.R.J.; Lafane, S.; Tessier, P.Y.; Angleraud, B.; Richard-Plouet, M.; Brohan, L.; Djouadi, M.A.

2006-01-01

Bi 4-x La x Ti 3 O 12 (BLT x ) (x = 0 to 1) thin films were grown on silicon (100) and platinized substrates Pt/TiO 2 /SiO 2 /Si using RF diode sputtering, magnetron sputtering and pulsed laser deposition (PLD). Stoichiometric home-synthesized targets were used. Reactive sputtering was investigated in argon/oxygen gas mixture, with a pressure ranging from 0.33 to 10 Pa without heating the substrate. PLD was investigated in pure oxygen, at a chamber pressure of 20 Pa for a substrate temperature of 400-440 deg. C. Comparative structural, chemical, optical and morphological characterizations of BLT thin films have been performed by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), X-Ray Photoelectron Spectroscopy (XPS), Spectro-ellipsometric measurements (SE) and Atomic Force Microscopy (AFM). Both sputtering techniques allow to obtain uniform films with thickness ranging from 200 to 1000 nm and chemical composition varying from (Bi,La) 2 Ti 3 O 12 to (Bi,La) 4.5 Ti 3 O 12 , depending on deposition pressure and RF power. In addition, BLT films deposited by magnetron sputtering, at a pressure deposition ranging from 1.1 to 5 Pa, were well-crystallized after a post-deposition annealing at 650 deg. C in oxygen. They exhibit a refractive index and optical band gap of 2.7 and 3.15 eV, respectively. Regarding PLD, single phase and well-crystallized, 100-200 nm thick BLT films with a stoichiometric (Bi,La) 4 Ti 3 O 12 chemical composition were obtained, exhibiting in addition a preferential orientation along (200). It is worth noting that BLT films deposited by magnetron sputtering are as well-crystallized than PLD ones

Effect of substrate type on the electrical and structural properties of TiO2 thin films deposited by reactive DC sputtering

Science.gov (United States)

Cheng, Xuemei; Gotoh, Kazuhiro; Nakagawa, Yoshihiko; Usami, Noritaka

2018-06-01

Electrical and structural properties of TiO2 thin films deposited at room temperature by reactive DC sputtering have been investigated on three different substrates: high resistivity (>1000 Ω cm) float zone Si(1 1 1), float zone Si(1 0 0) and alkali free glass. As-deposited TiO2 films on glass substrate showed extremely high resistivity of (∼5.5 × 103 Ω cm). In contrast, lower resistivities of ∼2 Ω cm and ∼5 Ω cm were obtained for films on Si(1 1 1) and Si(1 0 0), respectively. The as-deposited films were found to be oxygen-rich amorphous TiO2 for all the substrates as evidenced by X-ray photoemission spectroscopy and X-ray diffraction. Subsequent annealing led to appearance of anatase TiO2 on Si but not on glass. The surface of as-deposited TiO2 on Si was found to be rougher than that on glass. These results suggest that the big difference of electrical resistivity of TiO2 would be related with existence of more anatase nuclei forming on crystalline substrates, which is consistent with the theory of charged clusters that smaller clusters tend to adopt the substrate structure.

Sputtered titanium oxynitride coatings for endosseous applications: Physical and chemical evaluation and first bioactivity assays

Energy Technology Data Exchange (ETDEWEB)

Banakh, Oksana, E-mail: oksana.banakh@he-arc.ch [Institute of Applied Microtechnologies, Haute Ecole Arc Ingénierie (HES-SO), Eplatures-Grise 17, CH-2300 La Chaux-de-Fonds (Switzerland); Moussa, Mira, E-mail: mira.moussa@unige.ch [Laboratory of Biomaterials, University of Geneva, 19, rue Barthelemy Menn, CH-1205 Geneva (Switzerland); Matthey, Joel, E-mail: joel.matthey@he-arc.ch [Institute of Applied Microtechnologies, Haute Ecole Arc Ingénierie (HES-SO), Eplatures-Grise 17, CH-2300 La Chaux-de-Fonds (Switzerland); Pontearso, Alessandro, E-mail: alessandro.pontearso@he-arc.ch [Institute of Applied Microtechnologies, Haute Ecole Arc Ingénierie (HES-SO), Eplatures-Grise 17, CH-2300 La Chaux-de-Fonds (Switzerland); Cattani-Lorente, Maria, E-mail: maria.cattani-lorente@unige.ch [Laboratory of Biomaterials, University of Geneva, 19, rue Barthelemy Menn, CH-1205 Geneva (Switzerland); Sanjines, Rosendo, E-mail: rosendo.sanjines@epfl.ch [Ecole Polytechnique Fédérale de Lausanne (EPFL), Institute of Condensed Matter Physics, Station 3, CH-1015 Lausanne (Switzerland); Fontana, Pierre, E-mail: Pierre.Fontana@hcuge.ch [Haemostasis laboratory, Geneva University Hospital, Rue Gabrielle-Perret-Gentil 4, CH-1205 Geneva (Switzerland); Wiskott, Anselm, E-mail: anselm.wiskott@unige.ch [Laboratory of Biomaterials, University of Geneva, 19, rue Barthelemy Menn, CH-1205 Geneva (Switzerland); Durual, Stephane, E-mail: stephane.durual@unige.ch [Laboratory of Biomaterials, University of Geneva, 19, rue Barthelemy Menn, CH-1205 Geneva (Switzerland)

2014-10-30

Highlights: • Titanium oxynitride coatings (TiN{sub x}O{sub y}) with chemical composition ranging from TiN to TiO{sub 2} were deposited by magnetron sputtering from a metallic Ti target using a mixture of O{sub 2} + N{sub 2}. • The coatings structure as well as physical, chemical and mechanical properties progressively changes as a function of oxygen content in the TiN{sub x}O{sub y.} • All TiN{sub x}O{sub y} coatings show a significantly higher level of bioactivity as compared to bare Ti substrates (1.2 to 1.4 fold increase in cell proliferation). Despite variations in surface chemistry, topography and surface tension observed on films as a function of chemical composition, no significant differences in the films’ biological activity were observed after 3 days of testing. - Abstract: Titanium oxynitride coatings (TiN{sub x}O{sub y}) are considered a promising material for applications in dental implantology due to their high corrosion resistance, their biocompatibility and their superior hardness. Using the sputtering technique, TiN{sub x}O{sub y} films with variable chemical compositions can be deposited. These films may then be set to a desired value by varying the process parameters, that is, the oxygen and nitrogen gas flows. To improve the control of the sputtering process with two reactive gases and to achieve a variable and controllable coating composition, the plasma characteristics were monitored in-situ by optical emission spectroscopy. TiN{sub x}O{sub y} films were deposited onto commercially pure (ASTM 67) microroughened titanium plates by reactive magnetron sputtering. The nitrogen gas flow was kept constant while the oxygen gas flow was adjusted for each deposition run to obtain films with different oxygen and nitrogen contents. The physical and chemical properties of the deposited films were analyzed as a function of oxygen content in the titanium oxynitride. The potential application of the coatings in dental implantology was assessed by

Investigation of CaTiO3:Pr3+ thin films deposited by radiofrequency reactive magnetron sputtering for electroluminescence application

International Nuclear Information System (INIS)

Sarakha, L; Bousquet, A; Tomasella, E; Boutinaud, P; Mahiou, R

2010-01-01

In this report we successfully deposited thin films of CaTiO 3 :Pr 3+ by radiofrequency magnetron sputtering. The films were studied and we tried to understand the evolution of their optical and electrical properties. We noticed that the annealing temperature and the deposition pressures have an important influence on these properties. Thin films with good optical and electrical properties have been obtained. These films are transparent and are characterized by an intense red photoluminescence and a low fixed charge density. They are well dedicated for electroluminescence purposes.

Sputtering characteristics, crystal structures, and transparent conductive properties of TiO{sub x}N{sub y} films deposited on {alpha}-Al{sub 2}O{sub 3}(0 0 0 1) and glass substrates

Energy Technology Data Exchange (ETDEWEB)

Akazawa, Housei, E-mail: akazawa.housei@lab.ntt.co.jp [NTT Microsystem Integration Laboratories, 3-1 Morinosato Wakamiya, Atsugi, Kanagawa 243-0198 (Japan)

2012-12-15

Highlights: Black-Right-Pointing-Pointer Reactive sputtering of TiO{sub x}N{sub y} films was achieved under metal-mode conditions. Black-Right-Pointing-Pointer Partially substituting O in TiO{sub 2} with N formed anatase rather than rutile. Black-Right-Pointing-Pointer TiO{sub 2-x}N{sub x} on Al{sub 2}O{sub 3}(0 0 0 1) was more transparent and conductive than on glass substrate. Black-Right-Pointing-Pointer Nb{sup 5+} ions could be doped as donors in TiO{sub 2-x}N{sub x} anatase crystals. - Abstract: Adding N{sub 2} gas during reactive sputtering of a Ti target prevented the target surface from being severely poisoned by oxygen atoms and sustained a high deposition rate for titanium oxynitride films under metal-mode-like sputtering conditions. With progress in the degree of oxidization, films deposited onto a glass substrate varied from TiO{sub 1-x}N{sub x} having a face-centered cubic (fcc) structure to TiO{sub 2-x}N{sub x} having an anatase structure. Titanium oxynitride films deposited on an Al{sub 2}O{sub 3}(0 0 0 1) substrate were epitaxial with major orientations toward the (1 1 1) and (2 0 0) directions for fcc-TiO{sub 1-x}N{sub x} and (1 1 2) for anatase-TiO{sub 2-x}N{sub x}. Intermediately oxidized films between TiO{sub 1-x}N{sub x} and TiO{sub 2-x}N{sub x} were amorphous on the glass substrate but crystallized into a Magneli phase, Ti{sub n}O(N){sub 2n-1}, on the Al{sub 2}O{sub 3}(0 0 0 1) substrate. Partially substituting oxygen in TiO{sub 2} with nitrogen as well as continuously irradiating the growing film surface with a Xe plasma stream preferentially formed anatase rather than rutile. However, the occupation of anion sites with enough oxygen rather than nitrogen was the required condition for anatase crystals to form. The transparent conductive properties of epitaxial TiO{sub 2-x}N{sub x} films on Al{sub 2}O{sub 3}(0 0 0 1) were superior to those of microcrystalline films on the glass substrate. Since resistivity and optical transmittance of Ti

Ferroelectric properties of barium strontium titanate thin films grown by RF co-sputtering

International Nuclear Information System (INIS)

Zapata-Navarro, A.; Marquez-Herrera, A.; Cruz-Jauregui, M.P.; Calzada, M.L.

2005-01-01

In this work, we present the variation of the ferroelectric properties of Ba 1-x Sr x TiO 3 films deposited on Pt/TiO 2 /SiO 2 /Si substrates by RF co-sputtering with 0≤x≤1. The co-sputtering was done using a single magnetron with BaTiO 3 /SrTiO 3 targets in a pie mosaics configuration. Smooth and uniform films were obtained using the same conditions of growth and annealing temperature. The X-ray diffraction and EDS results show that the processes were managed to obtain crystalline materials with x from 0 to 1. The behaviour of P-E loops suggests that the ferroelectric properties of the films were tuned by changing the concentration of the cation. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Multilayer TiC/TiN diffusion barrier films for copper

International Nuclear Information System (INIS)

Yoganand, S.N.; Raghuveer, M.S.; Jagannadham, K.; Wu, L.; Karoui, A.; Rozgonyi, G.

2002-01-01

TiC/TiN thin films deposited by reactive magnetron sputtering on Si (100) substrates were investigated by transmission electron microscopy for microstructure and by deep level transient spectroscopy (DLTS) for diffusion barrier against copper. TiN thin films deposited on Si substrates at a substrate temperature of 600 deg. C were textured, and TiC thin films deposited at the same temperature were polycrystalline. TiC/TiN multilayer films also showed the same characteristics with the formation of an additional interaction layer. The diffusion barrier characteristics of the TiC/TiN/Si were determined by DLTS and the results showed that the films completely prevented diffusion of copper into Si

Influence of Substrate Biasing on (Ba,Sr)TiO3 Films Prepared by Electron Cyclotron Resonance Plasma Sputtering

Science.gov (United States)

Matsumoto, Takeshi; Niino, Atsushi; Ohtsu, Yasunori; Misawa, Tatsuya; Yonesu, Akira; Fujita, Hiroharu; Miyake, Shoji

2004-03-01

(Ba,Sr)TiO3 (BST) films were deposited by electron cyclotron resonance (ECR) plasma sputtering with mirror confinement. DC bias voltage was applied to Pt/Ti/SiO2/Si substrates during deposition to vary the intensity of bombardment of energetic ions and to modify film properties. BST films deposited on the substrates at floating potential (approximately +20 V) were found to be amorphous, while films deposited on +40 V-biased substrates were crystalline in spite of a low substrate temperature below 648 K. In addition, atomic diffusion, which causes deterioration in the electrical properties of the films, was hardly observed in the crystallized films deposited with +40 V bias perhaps due to the low substrate temperature. Plasma diagnoses revealed that application of a positive bias to the substrate reduced the energy of ion bombardment and increased the density of excited neutral particles, which was assumed to result in the promotion of chemical reactions during deposition and the crystallization of BST films at a low temperature.

Investigation of Corrosion Behavior of Ti/TiN Multilayers on Al7075 Deposited by High-Vacuum Magnetron Sputtering in 3.5% NaCl Solution

Science.gov (United States)

Molavi, Esfandiar; Shanaghi, Ali; Chu, Paul K.

2018-04-01

Although Al 7075 has many favorable mechanical properties such as the large strength-to-weight ratio, the relatively poor corrosion resistance has restricted industrial applications. In this work, Ti/TiN as hard multilayered and nanostructured coatings are deposited on the relatively soft Al 7075 structure by high-vacuum radio-frequency magnetron sputtering and the phase, structure, and morphology are investigated in details. The corrosion behavior is evaluated by electrochemical impedance spectroscopy in 3.5% NaCl at a pH of 7.5 for 1, 6, 12, 24, 36, 48, 60, and 72 h. At time points of 1, 6, 12, and 24 h, primary oxide layers and double layers are formed, but the corrosive medium penetrates the primary titanium nitride columnar structure. At longer time points of 24, 36, 48, 60, and 72 h, formation of stronger oxide and double layers leads to better corrosion resistance which is 14.8 times better than that observed from the uncoated substrate after immersion for 36 h. According to R ct, the corrosion resistances of the short and long immersion groups are 808.5-1984 and 808.5-1248 kΩ cm2, respectively, thereby confirming the effectiveness of the Ti/TiN coating against corrosion in comparison with the corrosion resistance of 84.3 kΩ cm2 observed from the uncoated Al 7075. The smallest corrosion resistance of 808.5 kΩ cm2 observed at the time point of 24 h is 9.6 times that of the uncoated substrate.

7 CFR 400.713 - Nonreinsured supplemental (NRS) policy.

Science.gov (United States)

2010-01-01

..., at least 120 days prior to the first sales closing date applicable to the policy. (b) FCIC will review the NRS policy to determine that it does not materially increase or shift risk to the underlying... the sales or administration of reinsured policies, undermines producers' confidence in the Federal...

Reactive dual magnetron sputtering for large area application

International Nuclear Information System (INIS)

Struempfel, J.

2002-01-01

Production lines for large area coating demand high productivity of reactive magnetron sputtering processes. Increased dynamic deposition rates for oxides and nitrides were already obtained by using of highly powered magnetrons in combination with advanced sputter techniques. However, besides high deposition rates the uniformity of such coatings has to be carefully considered. First the basics of reactive sputtering processes and dual magnetron sputtering are summarized. Different methods for process stabilization and control are commonly used for reactive sputtering. The Plasma Emission Monitor (PE M) offers the prerequisite for fast acting process control derived from the in-situ intensity measurements of a spectral line of the sputtered target material. Combined by multiple Plasma Emission Monitor control loops segmented gas manifolds are able to provide excellent thin film uniformity at high deposition rates. The Dual Magnetron allows a broad range of processing by different power supply modes. Medium frequency, DC and pulsed DC power supplies can be used for high quality layers. Whereas the large area coating of highly isolating layers like TiO 2 or SiO 2 is dominated by MF sputtering best results for coating with transparent conductive oxides are obtained by dual DC powering of the dual magnetron arrangement. (Author)

Surface characterizations of TiH{sub 2} powders before and after dehydrogenation

Energy Technology Data Exchange (ETDEWEB)

Zhang, Yeguang [School of Aeronautics & Astronautics, Sichuan University, Chengdu, 610065 (China); Wang, Chunming; Liu, Yang; Liu, Shaopeng; Xiao, Sufen [College of Materials Science and Engineering, Sichuan University, Chengdu, 610065 (China); Chen, Yungui, E-mail: ygchen60@aliyun.com [School of Aeronautics & Astronautics, Sichuan University, Chengdu, 610065 (China); College of Materials Science and Engineering, Sichuan University, Chengdu, 610065 (China)

2017-07-15

Highlights: • Oxides characteristics of TiH{sub 2} and HDH-Ti are investigated by XPS depth profiles. • The relative contents of TiO{sub 2}, Ti{sub 2}O{sub 3} and TiO are lower after dehydrogenation. • The decrease of Ti{sub 2}O{sub 3} is more remarkable followed by TiO{sub 2}, TiO after dehydrogenation. • The H atoms of TiH{sub 2} react preferentially with Ti{sub 2}O{sub 3} followed by TiO{sub 2}, TiO. - Abstract: The oxide film of TiH{sub 2} and HDH-Ti powder are investigated using X-ray photoelectron spectroscopy (XPS). The XPS depth profiles indicate that there exists mainly Ti{sup 2+}, Ti{sup 3+}, Ti{sup 4+} and Ti{sup 0} on TiH{sub 2} and HDH-Ti surface. The intensities of Ti 2p decrease for Ti{sup 4+}, first increase and then decrease for Ti{sup 3+} and Ti{sup 2+}, and increase all the time for Ti{sup 0} in the surface layer of TiH{sub 2} and HDH-Ti with the sputtering depth increasing. The relative fractions of TiO{sub 2}, Ti{sub 2}O{sub 3} and TiO for the Ti 2p of TiH{sub 2} and HDH-Ti first decrease and then slow down with the sputtering depth increasing. Meanwhile, the relative fractions of TiO{sub 2} and TiO of HDH-Ti are lower than that of TiH{sub 2} after the sputtering depth of about 5 nm, and the fraction of Ti{sub 2}O{sub 3} of HDH-Ti is always lower that of TiH{sub 2}. In addition, the decrease of Ti{sub 2}O{sub 3} is much pronounced, followed by TiO{sub 2} and TiO before and after dehydrogenation when the sputtering depth is more than 5 nm. The XPS depth profiles and calculation results suggest that the release of H atoms removes the part of oxygen on TiH{sub 2} surface, which results in the thinner oxide layer and low oxygen content of HDH-Ti powder.

Tribological properties, corrosion resistance and biocompatibility of magnetron sputtered titanium-amorphous carbon coatings

Science.gov (United States)

Dhandapani, Vishnu Shankar; Subbiah, Ramesh; Thangavel, Elangovan; Arumugam, Madhankumar; Park, Kwideok; Gasem, Zuhair M.; Veeraragavan, Veeravazhuthi; Kim, Dae-Eun

2016-05-01

Amorphous carbon incorporated with titanium (a-C:Ti) was coated on 316L stainless steel (SS) by magnetron sputtering technique to attain superior tribological properties, corrosion resistance and biocompatibility. The morphology, topography and functional groups of the nanostructured a-C:Ti coatings in various concentrations were analyzed using atomic force microscopy (AFM), Raman, X-Ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). Raman and XPS analyses confirmed the increase in sp2 bonds with increasing titanium content in the a-C matrix. TEM analysis confirmed the composite nature of the coating and the presence of nanostructured TiC for Ti content of 2.33 at.%. This coating showed superior tribological properties compared to the other a-C:Ti coatings. Furthermore, electrochemical corrosion studies were performed against stimulated body fluid medium in which all the a-C:Ti coatings showed improved corrosion resistance than the pure a-C coating. Preosteoblasts proliferation and viability on the specimens were tested and the results showed that a-C:Ti coatings with relatively high Ti (3.77 at.%) content had better biocompatibility. Based on the results of this work, highly durable coatings with good biocompatibility could be achieved by incorporation of optimum amount of Ti in a-C coatings deposited on SS by magnetron sputtering technique.

Au nanostructure-decorated TiO2 nanowires exhibiting photoactivity across entire UV-visible region for photoelectrochemical water splitting.

Science.gov (United States)

Pu, Ying-Chih; Wang, Gongming; Chang, Kao-Der; Ling, Yichuan; Lin, Yin-Kai; Fitzmorris, Bob C; Liu, Chia-Ming; Lu, Xihong; Tong, Yexiang; Zhang, Jin Z; Hsu, Yung-Jung; Li, Yat

2013-08-14

Here we demonstrate that the photoactivity of Au-decorated TiO2 electrodes for photoelectrochemical water oxidation can be effectively enhanced in the entire UV-visible region from 300 to 800 nm by manipulating the shape of the decorated Au nanostructures. The samples were prepared by carefully depositing Au nanoparticles (NPs), Au nanorods (NRs), and a mixture of Au NPs and NRs on the surface of TiO2 nanowire arrays. As compared with bare TiO2, Au NP-decorated TiO2 nanowire electrodes exhibited significantly enhanced photoactivity in both the UV and visible regions. For Au NR-decorated TiO2 electrodes, the photoactivity enhancement was, however, observed in the visible region only, with the largest photocurrent generation achieved at 710 nm. Significantly, TiO2 nanowires deposited with a mixture of Au NPs and NRs showed enhanced photoactivity in the entire UV-visible region. Monochromatic incident photon-to-electron conversion efficiency measurements indicated that excitation of surface plasmon resonance of Au is responsible for the enhanced photoactivity of Au nanostructure-decorated TiO2 nanowires. Photovoltage experiment showed that the enhanced photoactivity of Au NP-decorated TiO2 in the UV region was attributable to the effective surface passivation of Au NPs. Furthermore, 3D finite-difference time domain simulation was performed to investigate the electrical field amplification at the interface between Au nanostructures and TiO2 upon SPR excitation. The results suggested that the enhanced photoactivity of Au NP-decorated TiO2 in the UV region was partially due to the increased optical absorption of TiO2 associated with SPR electrical field amplification. The current study could provide a new paradigm for designing plasmonic metal/semiconductor composite systems to effectively harvest the entire UV-visible light for solar fuel production.

Deposition of Cr, Nb, V, and Ti coatings on UO2-25w/oPuO2 fuel pellets by sputtering

International Nuclear Information System (INIS)

Gibby, R.L.; McClanahan, E.D.

1976-01-01

A sputtering deposition process was developed for application of metallic coatings on either the ends or circumferences of LMFBR mixed-oxide fuel pellets. Coatings of Cr, Nb, V and Ti were applied to over 860 pellets. Ceramography, emission spectrography, and spark source spectroscopy were used to characterize the coatings. Coating thicknesses were controlled to within +-0.0005 cm (0.0002 inch) for a coating thickness of 0.00127 cm (0.0005 inch) on the circumference and 0.00254 cm (0.001 inch) on the ends of pellets. Chemical impurities in the coatings were generally less than 0.5 wt percent. The coatings were adherent in all cases, although some interfacial separations were noted with Ti coatings. The results indicated that further optimization of coatings' parameters would result in improvement of the coatings

Ferroelectric properties of barium strontium titanate thin films grown by RF co-sputtering

Energy Technology Data Exchange (ETDEWEB)

Zapata-Navarro, A.; Marquez-Herrera, A. [CICATA-IPN, Km. 14.5 Carretera Tampico-Puerto Ind. Altamira, Altamira Tamaulipas 89600 (Mexico); Cruz-Jauregui, M.P. [CCMC-UNAM, Km. 107 Carretera Tijuana-Ensenada, Ensenada B.C. 22800 (Mexico); Calzada, M.L. [ICMM (CSIC) Madrid, Cantoblanco Madrid 28049 (Spain)

2005-08-01

In this work, we present the variation of the ferroelectric properties of Ba{sub 1-x}Sr{sub x}TiO{sub 3} films deposited on Pt/TiO{sub 2}/SiO{sub 2}/Si substrates by RF co-sputtering with 0{<=}x{<=}1. The co-sputtering was done using a single magnetron with BaTiO{sub 3}/SrTiO{sub 3} targets in a pie mosaics configuration. Smooth and uniform films were obtained using the same conditions of growth and annealing temperature. The X-ray diffraction and EDS results show that the processes were managed to obtain crystalline materials with x from 0 to 1. The behaviour of P-E loops suggests that the ferroelectric properties of the films were tuned by changing the concentration of the cation. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Wear evaluation of WC inserts coated with TiN/TiAlN multinanolayers

OpenAIRE

Moreno, L. H.; Ciacedo, J. C.; Martinez, F.; Bejarano, G.; Battaille, T. S.; Prieto, P.

2010-01-01

TiN/TiAlN multilayers were deposited by radio frequency, r.f., reactive magnetron sputtering by using titanium and aluminum targets with 10 cm diameter and 99.99% purity in an argon/nitrogen atmosphere, applying a substrate temperature of 300 ºC. WC inserts were used as substrates to improve the mechanical and tribological properties of TiN/TiAlN multilayered coatings compared to other types of coatings like TiAlN monolayers and to manage greater efficiency of these coatings in different indu...

A hybrid heterojunction with reverse rectifying characteristics fabricated by magnetron sputtered TiOx and plasma polymerized aniline structure

International Nuclear Information System (INIS)

Sarma, Bimal K; Pal, Arup R; Bailung, Heremba; Chutia, Joyanti

2012-01-01

A TiO x film produced by direct current reactive magnetron sputtering without substrate heating or post-deposition annealing and a plasma polymerized aniline (PPA) structure deposited in the same reactor by a radio-frequency glow discharge without the assistance of a carrier gas are used for the fabrication of a heterojunction. The gas phase discharge is investigated by a Langmuir probe and optical emission spectroscopy. The individual layers and the heterojunction are characterized for structural and optoelectronic properties. PPA has polymer-like structure and texture and is characterized by saturated-unsaturated, branched and crosslinked networks. X-ray photoelectron spectroscopy reveals a slightly reduced TiO x surface, which exhibits near band edge luminescence. The free radicals trapped in PPA readily react with oxygen when exposed to atmosphere. The heterojunction shows reverse rectifying characteristics under dark and ultraviolet (UV) irradiation. The energy levels of TiO x and PPA might exhibit reverse band bending and electrons and holes are accumulated on both sides of the heterojunction. The charge accumulation phenomena at the interface may play a key role in the device performance of a hybrid heterojunction. The current-voltage characteristic of the heterojunction is sensitive to UV light, so the structure may be used for photo-sensing applications. (paper)

Effect of Nitrogen Content on Physical and Chemical Properties of TiN Thin Films Prepared by DC Magnetron Sputtering with Supported Discharge

Science.gov (United States)

Kavitha, A.; Kannan, R.; Gunasekhar, K. R.; Rajashabala, S.

2017-10-01

Amorphous titanium nitride (TiN) thin films have been prepared on silicon (Si) and glass substrates by direct-current (DC) reactive magnetron sputtering with a supported discharge (triode). Nitrogen gas (N2) at partial pressure of 0.3 Pa, 0.4 Pa, 0.5 Pa, and 0.6 Pa was used to prepare the TiN thin films, maintaining total pressure of argon and N2 of about 0.7 Pa. The chemical, microstructural, optical, and electrical properties of the TiN thin films were systematically studied. Presence of different phases of Ti with nitrogen (N), oxygen (O2), and carbon (C) elements was revealed by x-ray photoelectron spectroscopy characterization. Increase in the nitrogen pressure from 0.3 Pa to 0.6 Pa reduced the optical bandgap of the TiN thin film from 2.9 eV to 2.7 eV. Photoluminescence study showed that TiN thin film deposited at N2 partial pressure of 0.3 Pa exhibited three shoulder peaks at 330 nm, 335 nm, and 340 nm, which disappeared when the sample was deposited with N2 partial pressure of 0.6 Pa. Increase in the nitrogen content decreased the electrical resistivity of the TiN thin film from 3200 μΩ cm to 1800 μΩ cm. Atomic force microscopy studies of the TiN thin films deposited with N2 partial pressure of 0.6 Pa showed a uniform surface pattern associated with accumulation of fine grains. The results and advantages of this method of preparing TiN thin films are also reported.

Comparative study of nanocomposites prepared by pulsed and dc sputtering combined with plasma polymerization suitable for photovoltaic device applications

International Nuclear Information System (INIS)

Hussain, Amreen A.; Pal, Arup R.; Kar, Rajib; Bailung, Heremba; Chutia, Joyanti; Patil, Dinkar S.

2014-01-01

Plasma processing, a single step method for production of large area composite films, is employed to deposit plasma polymerized aniline-Titanium dioxide (PPani-TiO 2 ) nanocomposite thin films. The deposition of PPani-TiO 2 nanocomposite films are made using reactive magnetron sputtering and plasma polymerization combined process. This study focuses on the direct comparison between continuous and pulsed dc magnetron sputtering techniques of titanium in combination with rf plasma polymerization of aniline. The deposited PPani-TiO 2 nanocomposite films are characterized and discussed in terms of structural, morphological and optical properties. A self powered hybrid photodetector has been developed by plasma based process. The proposed method provides a new route where the self-assembly of molecules, that is, the spontaneous association of atomic or molecular building blocks under plasma environment, emerge as a successful strategy to form well-defined structural and morphological units of nanometer dimensions. - Highlights: • PPani-TiO 2 nanocomposite by pulsed and dc sputtering with rf plasma polymerization. • In-situ and Ex-situ H 2 SO 4 doping in PPani-TiO 2 nanocomposite. • PPani-TiO 2 nanocomposite based self-powered-hybrid photodetector

Effect of substrate temperature in the structural, optical and ferroelectric properties of thin films of BaTiO{sub 3} deposited by RF sputtering; Efecto de la temperatura de substrato en las propiedades estructurales, opticas y ferroelectricas de peliculas delgadas de BaTiO{sub 3} depositadas por RF sputtering

Energy Technology Data Exchange (ETDEWEB)

Marquez H, A. [Universidad Autonoma de San Luis Potosi, Coordinacion Academica Region Altiplano, Carretera a Cedral Km. 5 -600, Matehuala, 78800 San Luis Potosi (Mexico); Hernandez R, E.; Zapata T, M. [IPN, Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Unidad Legaria, Calz. Legaria 694, Col. Irrigacion, 11500 Mexico D. F. (Mexico); Calzadilla A, O. [Universidad de la Habana, Facultad de Fisica-IMRE, San Lazaro y L. Municipio Plaza de la Revolucion, La Habana (Cuba); Melendez L, M. [IPN, Centro de Investigacion y de Estudios Avanzados, Departamento de Fisica, Apdo. Postal 14-740, 07000 Mexico D. F. (Mexico)

2012-07-01

Thin films of Barium Titanate (BaTiO{sub 3}) were grown on nichrome and quartz substrates, using a BaTiO{sub 3} target, by RF sputtering technique. We varied the substrate temperature in order to study its effect on the structural, optical and ferroelectric properties of the samples. The results of the X-ray diffraction showed tetragonal structure with increases of the crystallinity as increases the substrate temperature. Furthermore, it observed by ultraviolet-visible spectroscopy that the band gap decreased as the substrate temperature increases showing abrupt sharp decrease at 494.8{sup o} C. The ferroelectric properties of the films showed a dependence with substrate temperature, the best ferroelectric answer was obtained at 494.8{sup o} C. (Author)

Effect of substrate roughness and working pressure on photocatalyst of N-doped TiOx films prepared by reactive sputtering with air

International Nuclear Information System (INIS)

Lee, Seon-Hong; Yamasue, Eiji; Okumura, Hideyuki; Ishihara, Keiichi N.

2015-01-01

Highlights: • Effect of substrate roughness and working pressure on the physical properties and the photocatalytic properties of the N-doped TiO x films are investigated. • Surface roughness of glass substrate has little influence on the film properties, but significant influence on the photocatalytic ability. • Working pressure has little influence on the produced phases and the atomic bonding configurations, but significant influence on the atomic concentration of the N-doped TiO x film. • High photocatalysis of N-doped TiO x film requires the permissible range of the N doping concentration which shows the interstitial complex N doping states in TiO 2 . - Abstract: N-doped TiO x films on the glass substrate were prepared by radio-frequency (RF) magnetron reactive sputtering of Ti target in a mixed gas of argon and dry air. The effect of substrate roughness and working pressure on the physical properties and the photocatalytic properties of the N-doped TiO x films was investigated. The surface roughness of glass substrate has little influence on the film properties such as produced phases, lattice parameters, introduced nitrogen contents, and atomic bonding configurations, but significant influence on the surface roughness of film resulting in the variation of the photocatalytic ability. The working pressure has little influence on the produced phases and the atomic bonding configurations, but significant influence on the atomic concentration of the N-doped TiO x film, resulting in the large variation of optical, structural, and photocatalytic properties. It is suggested that the high photocatalysis of N-doped TiO x film requires a certain range of the N doping concentration which shows the interstitial complex N doping states in TiO 2

Composition and crystal structure of N doped TiO2 film deposited at different O2 flow rate by direct current sputtering.

Science.gov (United States)

Ding, Wanyu; Ju, Dongying; Chai, Weiping

2011-06-01

N doped Ti02 films were deposited by direct current pulse magnetron sputtering system at room temperature. The influence of 02 flow rate on the crystal structure of deposited films was studied by Stylus profilometer, X-ray photoelectron spectroscopy, and X-ray diffractometer. The results indicate that the 02 flow rate strongly controls the growth behavior and crystal structure of N doped Ti02 film. It is found that N element mainly exists as substitutional doped state and the chemical stiochiometry is near to TiO1.68±0.06N0.11±0.01 for all film samples. N doped Ti02 film deposited with 2 sccm (standard-state cubic centimeter per minute) 02 flow rate is amorphous structure with high growth rate, which contains both anatase phase and rutile phase crystal nucleuses. In this case, the film displays the mix-phase of anatase and rutile after annealing treatment. While N doped Ti02 film deposited with 12 cm(3)/min 02 flow rate displays anatase phase before and after annealing treatment. And it should be noticed that no TiN phase appears for all samples before and after annealing treatment. Copyright © 2011 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

Microstructure and mechanical properties of Ti/Al co-doped DLC films: Dependence on sputtering current, source gas, and substrate bias

International Nuclear Information System (INIS)

Guo, Ting; Kong, Cuicui; Li, Xiaowei; Guo, Peng; Wang, Zhenyu; Wang, Aiying

2017-01-01

Highlights: • Ti/Al co-doped diamond-like carbon films were fabricated by a hybrid ion beam method. • Process parameters affected the structure and chemical state of co-doped Ti and Al. • The relation between microstructure and properties was investigated systematically. • The guidance to tailor the Ti/Al-DLC films with high performance was provided. - Abstract: Co-doping two metal elements into diamond-like carbon (DLC) films can reach the desirable combined properties, but the preparation and commercialized application of metal co-doped DLC films with well-defined structural properties are currently hindered by the non-comprehensive understanding of structural evolutions under different process parameters. Here, we fabricated the Ti/Al-DLC films using a unique hybrid ion beam system which enabled the independent control of metal content and carbon structure. The evolutions of microstructure, residual compressive stress and mechanical properties induced by the different process parameters including sputtering currents, C_2H_2 or CH_4 source gases and bias voltages were investigated systematically in order to perform in-depth analysis on the relation between the structure and properties in Ti/Al-DLC films. Results revealed that the variations of process parameters seriously affected the concentration and chemical bond state of co-doped Ti/Al atoms in amorphous carbon matrix or incident energies of C ions, which brought the complicated effect on amorphous carbon structures, accounting for the change of residual compressive stress, hardness and toughness. The present results provide the guidance for suitable, effective parameters selection to tailor the Ti/Al-DLC films with high performance for further applications.

Microstructure and mechanical properties of Ti/Al co-doped DLC films: Dependence on sputtering current, source gas, and substrate bias

Energy Technology Data Exchange (ETDEWEB)

Guo, Ting [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); School of Materials Science and Engineering, Shanghai University, Shanghai 200444 (China); Kong, Cuicui [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Ningbo University, Ningbo 315201 (China); Li, Xiaowei, E-mail: lixw@nimte.ac.cn [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Guo, Peng; Wang, Zhenyu [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Wang, Aiying, E-mail: aywang@nimte.ac.cn [Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China)

2017-07-15

Highlights: • Ti/Al co-doped diamond-like carbon films were fabricated by a hybrid ion beam method. • Process parameters affected the structure and chemical state of co-doped Ti and Al. • The relation between microstructure and properties was investigated systematically. • The guidance to tailor the Ti/Al-DLC films with high performance was provided. - Abstract: Co-doping two metal elements into diamond-like carbon (DLC) films can reach the desirable combined properties, but the preparation and commercialized application of metal co-doped DLC films with well-defined structural properties are currently hindered by the non-comprehensive understanding of structural evolutions under different process parameters. Here, we fabricated the Ti/Al-DLC films using a unique hybrid ion beam system which enabled the independent control of metal content and carbon structure. The evolutions of microstructure, residual compressive stress and mechanical properties induced by the different process parameters including sputtering currents, C{sub 2}H{sub 2} or CH{sub 4} source gases and bias voltages were investigated systematically in order to perform in-depth analysis on the relation between the structure and properties in Ti/Al-DLC films. Results revealed that the variations of process parameters seriously affected the concentration and chemical bond state of co-doped Ti/Al atoms in amorphous carbon matrix or incident energies of C ions, which brought the complicated effect on amorphous carbon structures, accounting for the change of residual compressive stress, hardness and toughness. The present results provide the guidance for suitable, effective parameters selection to tailor the Ti/Al-DLC films with high performance for further applications.

Electrochemical behavior of hydroxyapatite/TiN multi-layer coatings on Ti alloys

Energy Technology Data Exchange (ETDEWEB)

Kim, Eun-Ju [Department of Dental Materials, Research Center of Nano-Interface Activation for Biomaterials, School of Dentistry, Chosun University (Korea, Republic of); Jeong, Yong-Hoon [Biomechanics and Tissue Engineering Laboratory, Division of Orthodontics, College of Dentistry, The Ohio State University, Columbus, OH (United States); Choe, Han-Cheol, E-mail: hcchoe@chosun.ac.kr [Department of Dental Materials, Research Center of Nano-Interface Activation for Biomaterials, School of Dentistry, Chosun University (Korea, Republic of); Brantley, William A. [Division of Restorative Science and Prosthodontics, College of Dentistry, The Ohio State University, Columbus, OH (United States)

2014-12-01

The electrochemical behavior of hydroxyapatite (HA) and titanium nitride (TiN) multi-layer coatings on Ti–Nb–Zr alloys was investigated by a variety of surface analytical methods. The HA/TiN layers were deposited using a magnetron sputtering system. The HA target was made of human tooth-ash sintered at 1300 °C for 1 h and had an average Ca/P ratio of 1.9. From X-ray diffraction patterns, the Ti–29Nb–5Zr alloy was composed entirely of equiaxed β-phase exhibiting the principal (110) reflection, and the coating exhibited the (111) and (200) reflections for TiN and the (112) and (202) reflections for HA. At the coating surface the HA films consisted of granular particles, and the surface roughness was 4.22 nm. The thickness of the coating layers increased in the order of HA/TiN (lowest), TiN, and HA (highest). Potentiodynamic polarization measurements revealed that the corrosion current density was the lowest, and the corrosion potential and polarization resistance the highest, when the Ti–29Nb–5Zr surface was covered by the HA/TiN film, compared to solely HA or TiN films. - Highlights: • HA/TiN films were deposited by magnetron sputtering on a Ti–29Nb–5Zr biomedical alloy. • The corrosion current density for the HA/TiN films was lower than that of the non-coated alloy. • The polarization resistance of the HA/TiN films was higher than that of the non-coated alloy.

Electrochemical behavior of hydroxyapatite/TiN multi-layer coatings on Ti alloys

International Nuclear Information System (INIS)

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

2014-01-01

The electrochemical behavior of hydroxyapatite (HA) and titanium nitride (TiN) multi-layer coatings on Ti–Nb–Zr alloys was investigated by a variety of surface analytical methods. The HA/TiN layers were deposited using a magnetron sputtering system. The HA target was made of human tooth-ash sintered at 1300 °C for 1 h and had an average Ca/P ratio of 1.9. From X-ray diffraction patterns, the Ti–29Nb–5Zr alloy was composed entirely of equiaxed β-phase exhibiting the principal (110) reflection, and the coating exhibited the (111) and (200) reflections for TiN and the (112) and (202) reflections for HA. At the coating surface the HA films consisted of granular particles, and the surface roughness was 4.22 nm. The thickness of the coating layers increased in the order of HA/TiN (lowest), TiN, and HA (highest). Potentiodynamic polarization measurements revealed that the corrosion current density was the lowest, and the corrosion potential and polarization resistance the highest, when the Ti–29Nb–5Zr surface was covered by the HA/TiN film, compared to solely HA or TiN films. - Highlights: • HA/TiN films were deposited by magnetron sputtering on a Ti–29Nb–5Zr biomedical alloy. • The corrosion current density for the HA/TiN films was lower than that of the non-coated alloy. • The polarization resistance of the HA/TiN films was higher than that of the non-coated alloy

Physical properties of homogeneous TiO.sub.2./sub. films prepared by high power impulse magnetron sputtering as a function of crystallographic phase and nanostructure

Czech Academy of Sciences Publication Activity Database

Straňák, Vítězslav; Čada, Martin; Quaas, M.; Block, S.; Bogdanowicz, R.; Kment, Štěpán; Wulff, H.; Hubička, Zdeněk; Helm, Ch.A.; Tichý, M.; Hippler, R.

2009-01-01

Roč. 42, č. 10 (2009), 105204/1-105204/12 ISSN 0022-3727 R&D Projects: GA AV ČR KAN301370701; GA AV ČR KJB100100805; GA AV ČR KAN400720701 Institutional research plan: CEZ:AV0Z10100522 Keywords : TiO 2 * high power magnteron sputtering * plasma diagnostic * film diagnostic Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.083, year: 2009

Investigation of various properties of HfO2-TiO2 thin film composites deposited by multi-magnetron sputtering system

Science.gov (United States)

Mazur, M.; Poniedziałek, A.; Kaczmarek, D.; Wojcieszak, D.; Domaradzki, J.; Gibson, D.

2017-11-01

In this work the properties of hafnium dioxide (HfO2), titanium dioxide (TiO2) and mixed HfO2-TiO2 thin films with various amount of titanium addition, deposited by magnetron sputtering were described. Structural, surface, optical and mechanical properties of deposited coatings were analyzed. Based on X-ray diffraction and Raman scattering measuremets it was observed that there was a significant influence of titanium concentration in mixed TiO2-HfO2 thin films on their microstructure. Increase of Ti content in prepared mixed oxides coatings caused, e.g. a decrease of average crystallite size and amorphisation of the coatings. As-deposited hafnia and titania thin films exhibited nanocrystalline structure of monoclinic phase and mixed anatase-rutile phase for HfO2 and TiO2 thin films, respectively. Atomic force microscopy investigations showed that the surface of deposited thin films was densely packed, crack-free and composed of visible grains. Surface roughness and the value of water contact angle decreased with the increase of Ti content in mixed oxides. Results of optical studies showed that all deposited thin films were well transparent in a visible light range. The effect of the change of material composition on the cut-off wavelength, refractive index and packing density was also investigated. Performed measurements of mechanical properties revealed that hardness and Young's elastic modulus of thin films were dependent on material composition. Hardness of thin films increased with an increase of Ti content in thin films, from 4.90 GPa to 13.7 GPa for HfO2 and TiO2, respectively. The results of the scratch resistance showed that thin films with proper material composition can be used as protective coatings in optical devices.

Titanium carbide coatings on molybdenum by means of reactive sputtering and electron beam techniques

International Nuclear Information System (INIS)

Obata, T.; Aida, H.; Hirohata, Y.; Mohri, M.; Yamashina, T.

1982-01-01

This study is an experimental investigation of TiC coatings on Mo substrate by means of a reactive r.f. sputtering in the presence of CH 4 and a chemical reaction with interdiffusion in the sandwich structure of Ti/C/Mo by electron beam evaporation and heating. Using the reactive sputtering method, a homogeneous TiC coating with stoichiometric composition and good adhesion could be produced in the conditions of the partial pressure range of CH 4 , 2 approx. equal to 5 x 10 -4 Torr (total pressure, Psub(Ar) + Psub(CH) 4 = 5.6 x 10 -2 Torr) at 300 0 C (substrate). By using the electron beams, successively evaporated carbon and Ti on a Mo substrate was heated to 700 0 C to form a TiC surface layer on the top which then remained stable during further heating to 1000 0 C. Godd adhesion was brought about by interdiffusion to produce Mo 2 C layer between TiC layer and Mo substrate. It was also found that further heating of the coating layers subsequent to Ti evaporation on the TiC layer produced thicker TiC layer due to a chemical reaction between Ti and inner carbon layers. This could be a promising method of in situ replenishment for TiC coatings on the first wall and the limiter materials. (orig.)

Hysteretic current-voltage characteristics in RF-sputtered nanocrystalline TiO2 thin films

International Nuclear Information System (INIS)

Villafuerte, Manuel; Juarez, Gabriel; Heluani, Silvia P. de; Comedi, David

2007-01-01

We have measured the current-voltage characteristics at room temperature of a nanocrystalline TiO 2 thin film fabricated by reactive RF-sputtering deposition and sandwiched between ITO (indium-tin-oxide)-buffered glass substrate and an indium top electrode. The I-V characteristics are ohmic for low voltages and become non-linear, hysteretic and asymmetric as the voltage is increased. The system is shown to be well represented by two distinct resistance states in the non-ohmic region. Current transient evolutions were also measured for constant voltage excitations. The resistance is stable in time for voltages in the ohmic regime. In contrast, for voltages in the non-ohmic regime, the resistance has a small variation for a short period of time (order of tens seconds) and then increases with time. For those transients, long characteristic times (on the order of tens of minutes up to hours) were found. The behavior of the system is discussed on the basis of experimental results reported in the literature for similar systems and existing models for electric-field induced resistive switching

3D periodic multiscale TiO_2 architecture: a platform decorated with graphene quantum dots for enhanced photoelectrochemical water splitting

International Nuclear Information System (INIS)

Xu, Zhen; Yin, Min; Lu, Linfeng; Chen, Xiaoyuan; Li, Dongdong; Sun, Jing; Ding, Guqiao; Chang, Paichun

2016-01-01

Micropatterned TiO_2 nanorods (TiO_2NRs) via three-dimensional (3D) geometry engineering in both microscale and nanoscale decorated with graphene quantum dots (GQDs) have been demonstrated successfully. First, micropillar (MP) and microcave (MC) arrays of anatase TiO_2 films are obtained through the sol–gel based thermal nanoimprinting method. Then they are employed as seed layers in hydrothermal growth to fabricate the 3D micropillar/microcave arrays of rutile TiO_2NRs (NR), which show much-improved photoelectrochemical water-splitting performance than the TiO_2NRs grown on flat seed layer. The zero-dimensional GQDs are sequentially deposited onto the surfaces of the microscale patterned nanorods. Owing to the fast charge separation that resulted from the favorable band alignment of the GQDs and rutile TiO_2, the MP-NR-GQDs electrode achieves a photocurrent density up to 2.92 mA cm"−"2 under simulated one-sun illumination. The incident-photon-to-current-conversion efficiency (IPCE) value up to 72% at 370 nm was achieved on the MP-NR-GQDs electrode, which outperforms the flat-NR counterpart by 69%. The IPCE results also imply that the improved photocurrent mainly benefits from the distinctly enhanced ultraviolet response. The work provides a cost-effective and flexible pathway to develop periodic 3D micropatterned photoelectrodes and is promising for the future deployment of high performance optoelectronic devices. (paper)

Effects of in-plane compressive stress on electrical properties of (Ba,Sr)TiO3 thin film capacitors prepared by on- and off-axis rf magnetron sputtering

International Nuclear Information System (INIS)

Park, Woo Young; Ahn, Kun Ho; Hwang, Cheol Seong

2003-01-01

This study investigated the structural and electrical properties of (Ba,Sr)TiO 3 (BST) thin film capacitors with thicknesses ranging from 18 to 215 nm, which were prepared by on- and off-axis rf magnetron sputtering technique on Pt/SiO 2 /Si substrates. The deposition rate and cation composition ratios of the films were controlled to be the same regardless of the sputtering geometry. All the films show elongations in the out-of-plane lattice spacing, suggesting the presence of compressive stress with a smaller value by on-axis sputtering than by the off-axis system. There was no thickness dependence of the strain in the polycrystalline BST films. The BST films deposited using the on-axis system showed a higher bulk dielectric constant with a higher interfacial capacitance and a lower leakage current level than the films produced by the off-axis system. The strain effect was proposed to explain the correlations between the structural and electrical properties

Influences of Indium Tin Oxide Layer on the Properties of RF Magnetron-Sputtered (BaSr)TiO3 Thin Films on Indium Tin Oxide-Coated Glass Substrate

Science.gov (United States)

Kim, Tae Song; Oh, Myung Hwan; Kim, Chong Hee

1993-06-01

Nearly stoichiometric ((Ba+Sr)/Ti=1.08-1.09) and optically transparent (BaSr)TiO3 thin films were deposited on an indium tin oxide (ITO)-coated glass substrate by means of rf magnetron sputtering for their application to the insulating layer of an electroluminescent flat panel display. The influence of the ITO layer on the properties of (BaSr)TiO3 thin films deposited on the ITO-coated substrate was investigated. The ITO layer did not affect the crystallographic orientation of (BaSr)TiO3 thin film, but enhanced the grain growth. Another effect of the ITO layer on (BaSr)TiO3 thin films was the interdiffusion phenomenon, which was studied by means of secondary ion mass spectrometry (SIMS). As the substrate temperature increased, interdiffusion intensified at the interface not only between the grown film and ITO layer but also between the ITO layer and base glass substrate. The refractive index (nf) of (BaSr)TiO3 thin film deposited on a bare glass substrate was 2.138-2.286, as a function of substrate temperature.

High rate reactive sputtering in an opposed cathode closed-field unbalanced magnetron sputtering system

Science.gov (United States)

Sproul, William D.; Rudnik, Paul J.; Graham, Michael E.; Rohde, Suzanne L.

1990-01-01

Attention is given to an opposed cathode sputtering system constructed with the ability to coat parts with a size up to 15 cm in diameter and 30 cm in length. Initial trials with this system revealed very low substrate bias currents. When the AlNiCo magnets in the two opposed cathodes were arranged in a mirrored configuration, the plasma density at the substrate was low, and the substrate bias current density was less than 1 mA/sq cm. If the magnets were arranged in a closed-field configuration where the field lines from one set of magnets were coupled with the other set, the substrate bias current density was as high as 5.7 mA/sq cm when NdFeB magnets were used. In the closed-field configuration, the substrate bias current density was related to the magnetic field strength between the two cathodes and to the sputtering pressure. Hard well-adhered TiN coatings were reactively sputtered in the opposed cathode system in the closed-field configuration, but the mirrored configuration produced films with poor adhesion because of etching problems and low plasma density at the substrate.

Does the NRS Capture Changes in Communication during Inpatient Stroke Rehabilitation?

Science.gov (United States)

Barr, Leigh G; Kubilius, Barbra; Ansley, Barb; Whiteman, Rhonda; Sahlas, Demetrios J

2017-10-01

In Ontario, the National Rehabilitation Reporting System (NRS) is mandated for use as a measurement of change for stroke patients after admission to and discharge from rehabilitation. The NRS includes the functional independence measure (FIM) and supplementary measurement items developed by the Canadian Institute for Health Information (CIHI). Uncertainty exists regarding the efficacy of the NRS as the sole measure of outcome for communication in stroke rehabilitation patients. The use of additional speech-language pathology outcome measurement tools for this population has therefore been suggested. This study sought to establish whether the FIM and CIHI communication items capture quantifiable gains during stroke rehabilitation and therefore whether additional measures are needed to assess outcomes. A retrospective analysis was completed of 1252 complete data records of stroke patients discharged from inpatient rehabilitation at Hamilton Health Sciences between 2006 and 2011. Statistically significant improvements were observed in all total matched FIM scores (M = 72.68 to M = 96.39, P communication are therefore not required to assess outcomes in rehabilitation of stroke patients, although additional research is necessary to evaluate the clinical significance of the improvements that are observed using existing measurements of change. Copyright © 2017 National Stroke Association. All rights reserved.

The influence of annealing treatments on the properties of Ag:TiO{sub 2} nanocomposite films prepared by magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Adochite, R.C. [Centro de Fisica, Universidade do Minho, Campus de Azurem, 4800-058 Guimaraes (Portugal); Department of Materials Science and Engineering, ' Transilvania' University, 29 Eroilor Blvd., 500036 Brasov (Romania); Munteanu, D., E-mail: muntean.d@unitbv.ro [Department of Materials Science and Engineering, ' Transilvania' University, 29 Eroilor Blvd., 500036 Brasov (Romania); Torrell, M.; Cunha, L. [Centro de Fisica, Universidade do Minho, Campus de Azurem, 4800-058 Guimaraes (Portugal); Alves, E.; Barradas, N.P. [Instituto Tecnologico e Nuclear, Dept. Fisica, Apartado 21, E.N. 10, 2686-953 Sacavem (Portugal); Cavaleiro, A. [SEC-CEMUC - Universidade de Coimbra, Dept. Eng. Mecanica, Polo II, 3030-788 Coimbra (Portugal); Riviere, J.P.; Le Bourhis, E.; Eyidi, D. [Institut Pprime, UPR 3346-CNRS-Universite de Poitiers-ENSMA, SP2MI, teleport2, Bd M. et Pierre Curie, BP 30179, 86962 Futuroscope-Chasseneuil (France); Vaz, F. [Centro de Fisica, Universidade do Minho, Campus de Azurem, 4800-058 Guimaraes (Portugal)

2012-02-01

The present paper reports on the preparation and characterization of DC reactive magnetron sputtered Ag:TiO{sub 2} nanocomposite coatings, with a silver content of about 8 at.% (average estimation). The as-deposited samples were subjected to annealing, in a protective atmosphere, at temperatures ranging from 200 to 800 Degree-Sign C. Morphology, structure, hardness and friction behaviour were characterised after each heat treatment. The cross-sections of the films were studied by transmission electron microscopy (TEM). X-ray diffraction (XRD) was used to determine the thin-film structure and crystallinity as a function of annealing temperature. XRD analysis confirmed the presence of silver in all the samples and the crystallization of the TiO{sub 2} matrix for the samples annealed at temperatures above 300 Degree-Sign C. These structural changes were also followed by significant morphological variations, which resulted in the change of the mechanical properties of the films (hardness and Young's modulus) as well as of their tribological behaviour.

Effects of deposition and post-annealing conditions on electrical properties and thermal stability of TiAlN films by ion beam sputter deposition

International Nuclear Information System (INIS)

Lee, S.-Y.; Wang, S.-C.; Chen, J.-S.; Huang, J.-L.

2006-01-01

TiAlN films were deposited by ion beam sputter deposition (IBSD) using a Ti-Al (90/10) alloy target in a nitrogen atmosphere on thermal oxidized Si wafers. Effects of ion beam voltage, substrate temperature (T s ) and post-annealing conditions on electrical properties and oxidation resistance of TiAlN films were studied. According to the experimental results, the proper kinetic energy provided good crystallinity and a dense structure of the films. Because of their better crystallinity and predomination of (200) planes, TiAlN films deposited with 900 V at low T s (50 deg. C) have shown lower resistivity than those at high T s (250 deg. C). They also showed better oxidation resistance. If the beam voltage was too high, it caused some damage to the film surfaces, which caused poor oxidation resistance of films. When sufficient kinetic energy was provided by the beam voltage, the mobility of adatoms was too high due to their extra thermal energy, thus reducing the crystallinity and structure density of the films. A beam voltage of 900 V and a substrate temperature of 50 deg. C were the optimum deposition conditions used in this research. They provided good oxidation resistance and low electrical resistivity for IBSD TiAlN films

Comparative study of nanocomposites prepared by pulsed and dc sputtering combined with plasma polymerization suitable for photovoltaic device applications

Energy Technology Data Exchange (ETDEWEB)

Hussain, Amreen A. [Physical Sciences Division, Institute of Advanced Study in Science and Technology, Guwahati, Assam (India); Pal, Arup R., E-mail: arpal@iasst.gov.in [Physical Sciences Division, Institute of Advanced Study in Science and Technology, Guwahati, Assam (India); Kar, Rajib [Laser and Plasma Technology Division, Bhabha Atomic Research Center, Trombay, Mumbai (India); Bailung, Heremba; Chutia, Joyanti [Physical Sciences Division, Institute of Advanced Study in Science and Technology, Guwahati, Assam (India); Patil, Dinkar S. [Laser and Plasma Technology Division, Bhabha Atomic Research Center, Trombay, Mumbai (India)

2014-12-15

Plasma processing, a single step method for production of large area composite films, is employed to deposit plasma polymerized aniline-Titanium dioxide (PPani-TiO{sub 2}) nanocomposite thin films. The deposition of PPani-TiO{sub 2} nanocomposite films are made using reactive magnetron sputtering and plasma polymerization combined process. This study focuses on the direct comparison between continuous and pulsed dc magnetron sputtering techniques of titanium in combination with rf plasma polymerization of aniline. The deposited PPani-TiO{sub 2} nanocomposite films are characterized and discussed in terms of structural, morphological and optical properties. A self powered hybrid photodetector has been developed by plasma based process. The proposed method provides a new route where the self-assembly of molecules, that is, the spontaneous association of atomic or molecular building blocks under plasma environment, emerge as a successful strategy to form well-defined structural and morphological units of nanometer dimensions. - Highlights: • PPani-TiO{sub 2} nanocomposite by pulsed and dc sputtering with rf plasma polymerization. • In-situ and Ex-situ H{sub 2}SO{sub 4} doping in PPani-TiO{sub 2} nanocomposite. • PPani-TiO{sub 2} nanocomposite based self-powered-hybrid photodetector.

Compositionally modulated multilayer diamond-like carbon coatings with AlTiSi multi-doping by reactive high power impulse magnetron sputtering

Science.gov (United States)

Dai, Wei; Gao, Xiang; Liu, Jingmao; Kwon, Se-Hun; Wang, Qimin

2017-12-01

Diamond-like carbon (DLC) coatings with AlTiSi multi-doping were prepared by a reactive high power impulse magnetron sputtering with using a gas mixture of Ar and C2H2 as precursor. The composition, microstructure, compressive stress, and mechanical property of the as-deposited DLC coatings were studied systemically by using SEM, XPS, TEM, Raman spectrum, stress-tester, and nanoindentation as a function of the Ar fraction. The results show that the doping concentrations of the Al, Ti and Si atoms increased as the Ar fraction increased. The doped Ti and Si preferred to bond with C while the doped Al mainly existed in oxidation state without bonding with C. As the doping concentrations increased, TiC carbide nanocrystals were formed in the DLC matrix. The microstructure of coatings changed from an amorphous feature dominant AlTiSi-DLC to a carbide nanocomposite AlTiSi-DLC with TiC nanoparticles embedding. In addition, the coatings exhibited the compositionally modulated multilayer consisting of alternate Al-rich layer and Al-poor layer due to the rotation of the substrate holder and the diffusion behavior of the doped Al which tended to separate from C and diffuse towards the DLC matrix surface owing to its weak interactions with C. The periodic Al-rich layer can effectively release the compressive stress of the coatings. On the other hand, the hard TiC nanoparticles were conducive to the hardness of the coatings. Consequently, the DLC coatings with relatively low residual stress and high hardness could be acquired successfully through AlTiSi multi-doping. It is believed that the AlCrSi multi-doping may be a good way for improving the comprehensive properties of the DLC coatings. In addition, we believe that the DLC coatings with Al-rich multilayered structure have a high oxidation resistance, which allows the DLC coatings application in high temperature environment.

The effect of O2 partial pressure on the structure and photocatalytic property of TiO2 films prepared by sputtering

International Nuclear Information System (INIS)

Liu Baoshun; Zhao Xiujian; Zhao Qingnan; Li Chunling; He Xin

2005-01-01

The TiO 2 films were prepared on slide substrates by dc reactive magnetron sputtering at different oxygen partial pressure, and were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and Fourier transform infrared spectrometry (FT-IR). The degradation of methyl orange aqueous solutions was used to evaluate the photocatalytic activity. The results show that all films show crystalline anatase structure irrespective of oxygen partial pressure. The surface oxygen element exists in three forms, the first one is TiO 2 , the second one is OH - and the last one is physical absorbed water. The films deposited at oxygen partial pressure of 0.035 and 0.040 mTorr present better photocatalytic activity, which shows clear tendency to increase with oxygen partial pressure. Such photocatalytic activity results are considered to correlate with the crystalline structure, grain sizes and the OH - concentration

Improvement of dielectric properties of BLT thin films deposited by magnetron sputtering

International Nuclear Information System (INIS)

Besland, M P; Barroy, P R J; Richard-Plouet, M; Tessier, P Y; Brohan, L; Djouadi, M A; Borderon, C; Tacon, S Le; Averty, D; Gundel, H W

2008-01-01

Well crystallized BLT thin films were deposited by RF magnetron sputtering using a target of Aurivillius phase Bi 3.25 La 0.75 Ti 3 O 12 (BLT 0,75 ), elaborated in our institute. RF sputtering experiments were performed at room temperature with an argon/oxygen mixture, in a pressure range of 20-50 mTorr. Optimisation of the plasma parameters, namely deposition pressure, RF power and oxygen content in the gas phase, allows obtaining BLT films with a chemical composition close to Bi 3.25 La 0.75 Ti 3 O 12 . After ex-situ annealing under oxygen atmosphere at 650 deg. C, BLT films deposited on Pt/TiO 2 /SiO 2 /Si (multilayer) substrates exhibit well defined rod-like grains morphology. A two step deposition process appeared to be necessary in order to reach satisfying dielectric properties. The effect of the plasma parameters on the chemical composition and electrical properties are presented and discussed

Effect of nitrogen doping on TiO.sub.x./sub.N.sub.y./sub. thin film formation at reactive high-power pulsed magnetron sputtering

Czech Academy of Sciences Publication Activity Database

Straňák, Vítězslav; Quaas, M.; Bogdanowicz, R.; Steffen, H.; Wulff, H.; Hubička, Zdeněk; Tichý, M.; Hippler, R.

2010-01-01

Roč. 43, č. 28 (2010), s. 1-7 ISSN 0022-3727 R&D Projects: GA AV ČR KAN301370701; GA MŠk(CZ) 1M06002 Grant - others:AVČR(CZ) M100100915 Institutional research plan: CEZ:AV0Z10100522 Keywords : magnetron sputtering * TiO 2 * pulse discharge * XRD * band gap Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.105, year: 2010 http://iopscience.iop.org/0022-3727/43/28/285203/

Comparison of mechanical behavior of TiN, TiNC, CrN/TiNC, TiN/TiNC films on 9Cr18 steel by PVD

Science.gov (United States)

Feng, Xingguo; Zhang, Yanshuai; Hu, Hanjun; Zheng, Yugang; Zhang, Kaifeng; Zhou, Hui

2017-11-01

TiN, TiNC, CrN/TiNC and TiN/TiNC films were deposited on 9Cr18 steel using magnetron sputtering technique. The morphology, composition, chemical state and crystalline structure of the films were observed and analyzed by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Hardness and adhesion force were tested by nanoindentation and scratch tester, respectively. The friction and wear behavior of TiN, TiNC, CrN/TiNC and TiN/TiNC films sliding against GCr15 balls were investigated and compared synthetically using ball-on-disk tribometer. It was found that Tisbnd N, Tisbnd C, Tisbnd Nsbnd C and Csbnd C bonds were formed. The TiN/TiNC film was composed of TiN, TiC and TiNC phases. Hardness and adhesion force results indicated that although the TiN film possessed the highest hardness, its adhesion force was lowest among all the films. Tribological test results showed that the friction coefficient of TiN/TiNC was much lower than that of TiN and the wear rate decreases remarkably from 2.3 × 10-15 m3/Nm to 7.1 × 10-16 m3/Nm, which indicated the TiN/TiNC film has better wear resistance.

Influence of substrate bias voltage on the properties of TiO2 deposited by radio-frequency magnetron sputtering on 304L for biomaterials applications

International Nuclear Information System (INIS)

Bait, L.; Azzouz, L.; Madaoui, N.; Saoula, N.

2017-01-01

Highlights: • TiO 2 films were deposited on stainless steel 304L RF magnetron sputtering at different substrate bias. • The hardness of TiO 2 coated 304L are higher than those obtained for uncoated substrate. • TiO 2 films provide good protection for stainless steel against corrosion in Ringer solution. - Abstract: The aim of this paper is to investigate the effect of the substrate bias, varied from 0 to −100 V, on the structure and properties of the TiO 2 thin films for biomaterials applications. The TiO 2 films were grown onto 304L stainless steel substrate using radio-frequency (rf) magnetron sputtering from a pure titanium target in Ar-O 2 gas mixture. The variation of substrate bias voltage from 0 to −100 V produces variations of structure and mechanical properties of the films. The deposited films were characterized by X-rays diffraction, nanoindentation and potentiodynamic polarization. Also, the friction and wear properties of TiO 2 films sliding against alumina ball in air were investigated. Experimental results showed that the thickness increases for non-biased substrate voltage to Vs = −100 V from 820 nm to 1936 nm respectively. The roughness is in the range of 50 nm and 14 nm. XRD results show that all structures of the films are crystalline and changed with varying the bias voltage. The anatase phase is predominant in the low negative bias range (0–50 V). The hardness significantly increased from 2.2 to 6.4 GPa when the bias voltage was increased from 0 to 75 V and then slightly decrease to 5.1 GPa as further increased to 100 V. At the same time, the results indicate that TiO 2 films deposited at −100 V exhibited better wear resistance compared to the other samples, i.e. the minimum wear rates and the lower coefficient of friction of 0.16. In order to simulate natural biological conditions, physiological serum (pH = 6.3), thermostatically controlled at 37 °C, was used as the electrolyte for the study of the electrochemical properties

Structural and biocompatible characterization of TiC/a:C nanocomposite thin films

International Nuclear Information System (INIS)

Balázsi, K.; Vandrovcová, M.; Bačáková, L.; Balázsi, Cs.

2013-01-01

In this work, sputtered TiC/amorphous C thin films have been developed in order to be applied as potential barrier coating for interfering of Ti ions from pure Ti or Ti alloy implants. Our experiments were based on magnetron sputtering method, because the vacuum deposition provides great flexibility for manipulating material chemistry and structure, leading to films and coatings with special properties. The films have been deposited on silicon (001) substrates with 300 nm thick oxidized silicon sublayer at 200 °C deposition temperature as model substrate. Transmission electron microscopy has been used for structural investigations. Thin films consisted of ∼ 20 nm TiC columnar crystals embedded by 5 nm thin amorphous carbon matrix. MG63 osteoblast cells have been applied for in vitro study of TiC nanocomposites. The cell culture tests give strong evidence of thin films biocompatibility. Highlights: ► The main goal of this work is the relatively easy preparation of nanocomposite TiC thin films by dc magnetron sputtering. ► TEM and HREM were applied for structural characterization of columnar TiC nanocrystals and amorphous carbon matrix. ► The biocompatibility of films was showed by MG63 human osteoblast like cells during 1, 3 and 7 days seeding

Controlled formation of anatase and rutile TiO

NARCIS (Netherlands)

Rafieian, Damon; Ogieglo, Wojciech; Savenije, T.J.; Lammertink, Rob G H

2015-01-01

We discuss the formation of TiO₂ thin films via DC reactive magnetron sputtering. The oxygen concentration during sputtering proved to be a crucial parameter with respect to the final film structure and properties. The initial deposition provided amorphous films that crystallise upon

In situ study of interface reactions of ion beam sputter deposited (Ba0.5Sr0.5)TiO3 films on Si, SiO2, and Ir

International Nuclear Information System (INIS)

Gao, Y.; Mueller, A.H.; Irene, E.A.; Auciello, O.; Krauss, A.; Schultz, J.A.

1999-01-01

(Ba 0.5 ,Sr 0.5 )TiO 3 (BST) thin films were deposited on MgO, Si, SiO 2 and Ir surfaces by ion beam sputter deposition in oxygen at 700 degree C. In situ spectroscopic ellipsometry (SE) has been used to investigate the evolution of the BST films on different surfaces during both deposition and postannealing processes. First, the optical constants of the BST films in the photon energy range of 1.5 - 4.5 eV were determined by SE analysis on crystallized BST films deposited on MgO single crystal substrates. The interfaces in BST/Si and BST/SiO 2 /Si structure were examined by SE and Auger electron spectroscopy depth profiles. Subcutaneous oxidation in the BST/Ir structure was observed by in situ SE during both ion beam sputter deposition and postdeposition annealing in oxygen at 700 degree C. A study of the thermal stability of the Ir/TiN/SiO 2 /Si structure in oxygen at 700 degree C was carried out using in situ SE. The oxidation of Ir was confirmed by x-ray diffraction. The surface composition and morphology evolution after oxidation were investigated by time of flight mass spectroscopy of recoiled ions (TOF-MSRI) and atomic force microscopy. It has been found that Ti from the underlying TiN barrier layer diffused through the Ir layer onto the surface and thereupon became oxidized. It was also shown that the surface roughness increases with increasing oxidation time. The implications of the instability of Ir/TiN/SiO 2 /Si structure on the performance of capacitor devices based on this substrate are discussed. It has been shown that a combination of in situ SE and TOF-MSRI provides a powerful methodology for in situ monitoring of complex oxide film growth and postannealing processes. copyright 1999 American Vacuum Society

Growth of epitaxial Pt thin films on (0 0 1) SrTiO{sub 3} by rf magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Kahsay, A. [Departament de Física Aplicada i Òptica, Universitat de Barcelona, 08028 Barcelona (Spain); Polo, M.C., E-mail: mcpolo@ub.edu [Departament de Física Aplicada i Òptica, Universitat de Barcelona, 08028 Barcelona (Spain); Ferrater, C.; Ventura, J. [Departament de Física Aplicada i Òptica, Universitat de Barcelona, 08028 Barcelona (Spain); Rebled, J.M. [Departament d’Electrònica, Universitat de Barcelona Institut de Nanociència i Nanotecnologia IN 2UB, 08028 Barcelona (Spain); Varela, M. [Departament de Física Aplicada i Òptica, Universitat de Barcelona, 08028 Barcelona (Spain)

2014-07-01

The growth of platinum thin film by rf magnetron sputtering on SrTiO{sub 3}(0 0 1) substrates for oxide based devices was investigated. Platinum films grown at temperatures higher than 750 °C were epitaxial ([1 0 0]Pt(0 0 1)//[1 0 0]STO(0 0 1)), whereas at lower temperatures Pt(1 1 1) films were obtained. The surface morphology of the Pt films showed a strong dependence on the deposition temperature as was revealed by atomic force microscopy (AFM). At elevated temperatures there is a three-dimensional (3D) growth of rectangular atomically flat islands with deep boundaries between them. On the other hand, at low deposition temperatures, a two-dimensional (2D) layered growth was observed. The transition from 2D to 3D growth modes was observed that occurs for temperatures around 450 °C. The obtained epitaxial thin films also formed an atomically sharp interface with the SrTiO{sub 3}(0 0 1) substrate as confirmed by HRTEM.

Investigation of photocatalytic activity of titanium dioxide deposited on metallic substrates by DC magnetron sputtering

DEFF Research Database (Denmark)

Daviðsdóttir, Svava; Canulescu, Stela; Dirscherl, Kai

2013-01-01

The photocatalytic properties of titanium dioxide (TiO2) coating in the anatase crystalline structure deposited on aluminium AA1050 alloy and stainless steel S316L substrates were investigated. The coating was prepared by DC magnetron sputtering. The microstructure and surface morphology of the c......The photocatalytic properties of titanium dioxide (TiO2) coating in the anatase crystalline structure deposited on aluminium AA1050 alloy and stainless steel S316L substrates were investigated. The coating was prepared by DC magnetron sputtering. The microstructure and surface morphology...... sweep voltammetry, impedance measurements. The microstructure and surface morphology of the coating were similar irrespective of the nature of the substrate, while the photocatalytic behaviour was found to vary depending on the substrate type. In general the TiO2 coating on stainless steel was shown...

Influence of annealing temperature on the structural, mechanical and wetting property of TiO2 films deposited by RF magnetron sputtering

International Nuclear Information System (INIS)

Pradhan, Swati S.; Sahoo, Sambita; Pradhan, S.K.

2010-01-01

TiO 2 films have been deposited on silicon substrates by radio frequency magnetron sputtering of a pure Ti target in Ar/O 2 plasma. The TiO 2 films deposited at room temperature were annealed for 1 h at different temperatures ranging from 400 o C to 800 o C. The structural, morphological, mechanical properties and the wetting behavior of the as deposited and annealed films were obtained using Raman spectroscopy, atomic force microscopy, transmission electron microscopy, nanoindentation and water contact angle (CA) measurements. The as deposited films were amorphous, and the Raman results showed that anatase phase crystallization was initiated at annealing temperature close to 400 o C. The film annealed at 400 o C showed higher hardness than the film annealed at 600 o C. In addition, the wettability of film surface was enhanced with an increase in annealing temperature from 400 o C to 800 o C, as revealed by a decrease in water CA from 87 o to 50 o . Moreover, the water CA of the films obtained before and after UV light irradiation revealed that the annealed films remained more hydrophilic than the as deposited film after irradiation.

Effect of oxygen incorporation on the structure and elasticity of Ti-Al-O-N coatings synthesized by cathodic arc and high power pulsed magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Hans, M., E-mail: hans@mch.rwth-aachen.de; Baben, M. to; Music, D.; Ebenhöch, J.; Schneider, J. M. [Materials Chemistry, RWTH Aachen University, Kopernikusstr. 10, D-52074 Aachen (Germany); Primetzhofer, D. [Department of Physics and Astronomy, Uppsala University, Lägerhyddsvägen 1, S-75120 Uppsala (Sweden); Kurapov, D.; Arndt, M.; Rudigier, H. [Oerlikon Balzers Coating AG, Iramali 18, LI-9496 Balzers, Principality of Liechtenstein (Liechtenstein)

2014-09-07

Ti-Al-O-N coatings were synthesized by cathodic arc and high power pulsed magnetron sputtering. The chemical composition of the coatings was determined by means of elastic recoil detection analysis and energy dispersive X-ray spectroscopy. The effect of oxygen incorporation on the stress-free lattice parameters and Young's moduli of Ti-Al-O-N coatings was investigated by X-ray diffraction and nanoindentation, respectively. As nitrogen is substituted by oxygen, implications for the charge balance may be expected. A reduction in equilibrium volume with increasing O concentration is identified by X-ray diffraction and density functional theory calculations of Ti-Al-O-N supercells reveal the concomitant formation of metal vacancies. Hence, the oxygen incorporation-induced formation of metal vacancies enables charge balancing. Furthermore, nanoindentation experiments reveal a decrease in elastic modulus with increasing O concentration. Based on ab initio data, two causes can be identified for this: First, the metal vacancy-induced reduction in elasticity; and second, the formation of, compared to the corresponding metal nitride bonds, relatively weak Ti-O and Al-O bonds.

Effect of oxygen incorporation on the structure and elasticity of Ti-Al-O-N coatings synthesized by cathodic arc and high power pulsed magnetron sputtering

International Nuclear Information System (INIS)

Hans, M.; Baben, M. to; Music, D.; Ebenhöch, J.; Schneider, J. M.; Primetzhofer, D.; Kurapov, D.; Arndt, M.; Rudigier, H.

2014-01-01

Ti-Al-O-N coatings were synthesized by cathodic arc and high power pulsed magnetron sputtering. The chemical composition of the coatings was determined by means of elastic recoil detection analysis and energy dispersive X-ray spectroscopy. The effect of oxygen incorporation on the stress-free lattice parameters and Young's moduli of Ti-Al-O-N coatings was investigated by X-ray diffraction and nanoindentation, respectively. As nitrogen is substituted by oxygen, implications for the charge balance may be expected. A reduction in equilibrium volume with increasing O concentration is identified by X-ray diffraction and density functional theory calculations of Ti-Al-O-N supercells reveal the concomitant formation of metal vacancies. Hence, the oxygen incorporation-induced formation of metal vacancies enables charge balancing. Furthermore, nanoindentation experiments reveal a decrease in elastic modulus with increasing O concentration. Based on ab initio data, two causes can be identified for this: First, the metal vacancy-induced reduction in elasticity; and second, the formation of, compared to the corresponding metal nitride bonds, relatively weak Ti-O and Al-O bonds

Light scattering by SiOsub(x) and TiOsub(x) films

Energy Technology Data Exchange (ETDEWEB)

Biedermann, A; Hacker, E; Schirmer, G; Walther, H G

1981-11-20

The scattering intensities of vapour-deposited SiOsub(x) films (x approx. <= 2) are the other of 10/sup -4/ if the incidence intensity is unity. This is of the same order of magnitude as the scattering intensity from highly polished optical glass surfaces. The low level of scattering results from the nearly amorphous film structure. Reactively evaporated TiOsub(x) films also exhibit a very low scattering intensity, whereas for reactively sputtered TiO/sub 2/ films the scattering intensity is strongly dependent on the partial pressure of oxygen in the sputtering gas. For films sputtered in 100% O/sub 2/ the scattering level amounts to a few per cent. This is due to the large grain sizes of up to 1 ..mu..m in these films. For low plasma oxygen concentrations TiO/sub 2/ films sputtered under unbiased conditions show microcrystalline sturctures of the anatase modification. However, when the oxygen partial pressure is increased and a bias voltage is applied to the substrate the rutile modification is produced.

Structural and dielectric studies of Co doped MgTiO3 thin films fabricated by RF magnetron sputtering

Directory of Open Access Journals (Sweden)

T. Santhosh Kumar

2014-06-01

Full Text Available We report the structural, dielectric and leakage current properties of Co doped MgTiO3 thin films deposited on platinized silicon (Pt/TiO2/SiO2/Si substrates by RF magnetron sputtering. The role of oxygen mixing percentage (OMP on the growth, morphology, electrical and dielectric properties of the thin films has been investigated. A preferred orientation of grains along (110 direction has been observed with increasing the OMP. Such evolution of the textured growth is explained on the basis of the orientation factor analysis followed the Lotgering model. (Mg1-xCoxTiO3 (x = 0.05 thin films exhibits a maximum relative dielectric permittivity of ɛr = 12.20 and low loss (tan δ ∼ 1.2 × 10−3 over a wide range of frequencies for 75% OMP. The role of electric field frequency (f and OMP on the ac-conductivity of (Mg0.95Co0.05TiO3 have been studied. A progressive increase in the activation energy (Ea and relative permittivity ɛr values have been noticed up to 75% of OMP, beyond which the properties starts deteriorate. The I-V characteristics reveals that the leakage current density decreases from 9.93 × 10−9 to 1.14 × 10−9 A/cm2 for OMP 0% to 75%, respectively for an electric field strength of 250 kV/cm. Our experimental results reveal up to that OMP ≥ 50% the leakage current mechanism is driven by the ohmic conduction, below which it is dominated by the schottky emission.

Structure and tribological behavior of Pb-Ti/MoS2 nanoscaled multilayer films deposited by magnetron sputtering method

Science.gov (United States)

Li, Hao; Xie, Mingling; Zhang, Guangan; Fan, Xiaoqiang; Li, Xia; Zhu, Minhao; Wang, Liping

2018-03-01

The Pb-Ti/MoS2 nanoscaled multilayer films with different bilayer period were deposited by unbalanced magnetron sputtering system. The morphology, microstructure, mechanical and tribological properties of the films were investigated. It was found that the film changed from multilayer structure to composite structure as the bilayer period decreased from 25 nm to 6 nm, due to the diffusion effect. The multilayer film showed a pronounced (002) diffraction peak, the growth of the MoS2 platelets below the interface were affected by Pb and Ti, and the c-axis of MoS2 platelets were inclined to the substrate at an angle of -30° to 30°. The hardness of the film ranged from 5.9 to 7.2 GPa depending on the bilayer period. The tribological behavior of the films was performed under vacuum, and the friction coefficient were typically below 0.25. Furthermore, the nanoscale multilayer film with a bilayer period of 20 nm exhibits much better mechanical and tribological properties than pure MoS2. The result indicates that the nanoscale multilayer is a design methodology for developing high basal plane oriented and vacuum solid lubricating MoS2 based materials.

Surface characterization of Zr/Ti/Nb tri-layered films deposited by magnetron sputtering on Si(111) and stainless steel substrates

Energy Technology Data Exchange (ETDEWEB)

Tallarico, Denise A.; Gobbi, Angelo L.; Filho, Pedro I. Paulin; Galtayries, Anouk; Nascente, Pedro A. P. [Federal University of Sao Carlos, Department of Materials Engineering, Via Washington Luis km 235, CEP 13565-905, Sao Carlos, SP (Brazil); Brazilian Synchrotron Light Laboratory, Microfabrication Laboratory, Rua Giuseppe Maximo Scolfaro 10.000, CEP 13083-100, Campinas, SP (Brazil); Federal University of Sao Carlos, Department of Materials Engineering, Via Washington Luis km 235, CEP 13565-905, Sao Carlos, SP (Brazil); Ecole Nationale Superieure de Chimie de Paris (Chimie ParisTech), Laboratoire de Physico-Chimie des Surfaces, UMR CNRS 7045, F-75231 Paris cedex 05 (France); Federal University of Sao Carlos, Department of Materials Engineering, Via Washington Luis km 235, CEP 13565-905, Sao Carlos, SP (Brazil)

2012-09-15

Among metallic materials, commercially pure titanium and titanium alloys are very often used as biomaterials for implants. Among these alloys, titanium-aluminum-vanadium alloy Ti-6 A-4 V is one of the most commonly used due to its excellent biocompatibility and ability to allow bone-implant integration. A new class of Ti alloys employs Zr for solid-solution hardening and Nb as {beta}-phase stabilizer. Metals such as Ti, Nb, and Zr-known as valve metals-usually have their surfaces covered by a thin oxide film that forms spontaneously in air. This oxide film constitutes a barrier between the metal and the medium. The Ti-Nb-Zr alloys have mechanical and corrosion resistance characteristics which make them suitable for use as implants. Tri-layered films of Ti-Nb-Zr were deposited on both Si(111) and stainless steel (SS) substrates using dc magnetron sputtering equipment, under an argon atmosphere according to the following methodology: a 100 nm thick layer of Nb was deposited on the substrate, followed by a 200 nm thick layer of Ti, and finally a 50 nm thick layer of Zr, on top of the multilayer stack. The morphology and chemical composition of the films were analyzed by atomic force microscopy (AFM), x-ray photoelectron spectroscopy (XPS), and time-of-flight secondary ion mass spectrometry (ToF-SIMS). AFM images showed that the Zr/Ti/Nb tri-layer films presented nanostructured grains and low roughness. The ToF-SIMS depth profiles confirmed the formation of a three-layered film on Si(111) with well-defined and sharp interfaces between the layers, while the deposition on the stainless steel substrate caused slight intermixing at the different alloy/Nb, Nb/Ti and Ti/Zr interfaces, reflecting the greater roughness of the raw substrate. The XPS results for the Zr/Ti/Nb layers deposited on Si(111) and SS confirmed that the outermost layer consisted of Zr only, with a predominance of ZrO{sub 2}, as the metal layer is passivated in air. An oxidation treatment of 1000 Degree

NRS-2002 for pre-treatment nutritional risk screening and nutritional status assessment in head and neck cancer patients.

Science.gov (United States)

Orell-Kotikangas, Helena; Österlund, Pia; Saarilahti, Kauko; Ravasco, Paula; Schwab, Ursula; Mäkitie, Antti A

2015-06-01

The aim of this study was to assess the value of nutritional risk screening-2002 (NRS-2002) as a nutritional risk screening and status assessment method and to compare it with nutritional status assessed by subjective and objective methods in the screening of head and neck cancer patients. Sixty-five consecutive patients (50 male), with a median age of 61 years (range, 33-77), with head and neck squamous cell carcinoma (HNSCC) were enrolled prior to cancer therapy. Nutritional status was assessed by NRS-2002, patient-generated subjective global assessment (PG-SGA), handgrip strength (HGS) and mid-arm muscle area (MAMA). Twenty-eight percent of patients were at nutritional risk based on NRS-2002, and 34 % were malnourished according to PG-SGA, while 43 % had low HGS. NRS-2002 cut-off score of ≥3 compared with the nutritional status according to PG-SGA showed 77 % specificity and 98 % sensitivity (K = 0.78). NRS-2002 was able to predict malnutrition (PG-SGA BC) both in men (p nutrition screening in head and neck cancer patients prior to oncological treatment.

Highly c-axis-oriented monocrystalline Pb(Zr, Ti)O₃ thin films on si wafer prepared by fast cooling immediately after sputter deposition.

Science.gov (United States)

Yoshida, Shinya; Hanzawa, Hiroaki; Wasa, Kiyotaka; Esashi, Masayoshi; Tanaka, Shuji

2014-09-01

We successfully developed sputter deposition technology to obtain a highly c-axis-oriented monocrystalline Pb(Zr, Ti)O3 (PZT) thin film on a Si wafer by fast cooling (~-180°C/min) of the substrate after deposition. The c-axis orientation ratio of a fast-cooled film was about 90%, whereas that of a slow-cooled (~-40°C/min) film was only 10%. The c-axis-oriented monocrystalline Pb(Zr0.5, Ti0.5)O3 films showed reasonably large piezoelectric coefficients, e(31,f) = ~-11 C/m(2), with remarkably small dielectric constants, ϵ(r) = ~220. As a result, an excellent figure of merit (FOM) was obtained for piezoelectric microelectromechanical systems (MEMS) such as a piezoelectric gyroscope. This c-axis orientation technology on Si will extend industrial applications of PZT-based thin films and contribute further to the development of piezoelectric MEMS.

Measurements of sputtering yields for low-energy plasma ions

International Nuclear Information System (INIS)

Nishi, M.; Yamada, M.; Suckewer, S.; Rosengaus, E.

1979-04-01

Sputtering yields of various wall/limiter materials of fusion devices have been extensively measured in the relevant plasma environment for low-energy light ions (E 14 cm -3 and electron temperature up to 10eV. Target materials used were C (graphite), Ti, Mo, Ta, W, and Fe (stainless steel). In order to study the dependence of the sputtering yields on the incident energy of ions, the target samples were held at negative bias voltage up to 300V. The sputtering yields were determined by a weight-loss method and by spectral line intensity measurements. The data obtained in the present experiment agree well with those previously obtained at the higher energies (E greater than or equal to 200eV) by other authors using different schemes; the present data also extend to substantially lower energies (E approx. > 30eV) than hitherto

XPS investigations of tribolayers formed on TiN and (Ti,Re)N coatings

Energy Technology Data Exchange (ETDEWEB)

Oktay, Serkan; Kahraman, Zafer; Urgen, Mustafa; Kazmanli, Kursat, E-mail: kursat@itu.edu.tr

2015-02-15

Graphical abstract: - Highlights: • The (Ti,Re)N coating (8 ± 1.9 at.% Re) consisted of TiN and ReNx (x > 1.33) phases. • TiO{sub 2} provided low friction coefficient to TiN coating at 150 °C. • Re addition to TiN drastically dropped the friction coefficients to 0.17–0.22. • Re{sub 2}O{sub 7} provided very low friction coefficient to (Ti,Re)N coating. • Re addition to TiN improved the wear behavior. - Abstract: TiN and (Ti,Re)N coatings were deposited on high-speed-steel substrates by a hybrid coating system composed of cathodic arc PVD and magnetron sputtering techniques. In order to keep rhenium content low (8 ± 1.9 at.%) in the coating, magnetron sputtering technique was utilized to evaporate rhenium. The (Ti,Re)N coating consisted of TiN and ReN{sub x} (x > 1.33) phases. The hardness of TiN and (Ti,Re)N were 31 GPa and 29 GPa ( ± 2 GPa), respectively. Tribological behaviors of the samples were tested against Al{sub 2}O{sub 3} balls at 21 °C (RT) and 150 °C (HT) by reciprocating wear technique. The tribolayers were analyzed by XPS technique. Friction coefficients of TiN were 0.56, 0.35 for 21 °C and 150 °C tests, respectively. Rhenium addition to TiN drastically dropped the friction coefficients to 0.22 and 0.17 for RT and HT samples. Rhenium addition also improved the wear resistance of the coating at both test temperatures. For TiN, main oxide component of the tribolayers was Ti{sub 2}O{sub 3} for RT tests and TiO{sub 2} for HT tests. The oxide layer formed on (Ti,Re)N were the mixture of TiO{sub 2}, Ti−O−N, ReO{sub 2} and Re{sub 2}O{sub 7} for both test temperatures. Re{sub 2}O{sub 7} provided very low friction coefficient to (Ti,Re)N. The findings are consistent with the crystal chemistry approach.

The Influence of a TiN Film on the Electronic Contribution to the Thermal Conductivity of a TiC Film in a TiN-TiC Layer System

Science.gov (United States)

Jagannadham, K.

2018-01-01

TiC and TiN films were deposited by reactive magnetron sputtering on Si substrates. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) characterization of the microstructure and interface structure have been carried out and the stoichiometric composition of TiC is determined. Thermal conductivity and interface thermal conductance between different layers in the films are evaluated by the transient thermo reflectance (TTR) and three-omega (3- ω) methods. The results showed that the thermal conductivity of the TiC films increased with temperature. The thermal conductivity of TiC in the absence of TiN is dominated by phonon contribution. The electronic contribution to the thermal conductivity of TiC in the presence of TiN is found to be more significant. The interface thermal conductance of the TiC/TiN interface is much larger than that of interfaces at Au/TiC, TiC/Si, or TiN/Si. The interface thermal conductance between TiC and TiN is reduced by the layer formed as a result of interdiffusion.

Annealing dependence of residual stress and optical properties of TiO2 thin film deposited by different deposition methods.

Science.gov (United States)

Chen, Hsi-Chao; Lee, Kuan-Shiang; Lee, Cheng-Chung

2008-05-01

Titanium oxide (TiO(2)) thin films were prepared by different deposition methods. The methods were E-gun evaporation with ion-assisted deposition (IAD), radio-frequency (RF) ion-beam sputtering, and direct current (DC) magnetron sputtering. Residual stress was released after annealing the films deposited by RF ion-beam or DC magnetron sputtering but not evaporation, and the extinction coefficient varied significantly. The surface roughness of the evaporated films exceeded that of both sputtered films. At the annealing temperature of 300 degrees C, anatase crystallization occurred in evaporated film but not in the RF ion-beam or DC magnetron-sputtered films. TiO(2) films deposited by sputtering were generally more stable during annealing than those deposited by evaporation.

Structural study of TiO2-based transparent conducting films

International Nuclear Information System (INIS)

Hitosugi, T.; Yamada, N.; Nakao, S.; Hatabayashi, K.; Shimada, T.; Hasegawa, T.

2008-01-01

We have investigated microscopic structures of sputter and pulsed laser deposited (PLD) anatase Nb-doped TiO 2 transparent conducting films, and discuss what causes the degradation of resistivity in sputter-deposited films. Cross-sectional transmission electron microscope and polarized optical microscope images show inhomogeneous intragrain structures and small grains of ∼10 μm in sputter-deposited films. From comparison with PLD films, these results suggest that homogeneous film growth is the important factor to obtain highly conducting sputter-deposited film

[Effects of magnetron sputtered ZrN on the bonding strength of titanium porcelain].

Science.gov (United States)

Zhou, Shu; Zhang, Wen-yan; Guang, Han-bing; Xia, Yang; Zhang, Fei-min

2009-04-01

To investigate the effect of magnetron sputtered ZrN on the bonding strength between a low-fusing porcelain (Ti/Vita titankeramik system) and commercially pure cast titanium. Sixteen specimens were randomly assigned to test group and control group (n=8). The control group received no surface treated. Magnetron sputtered ZrN film was deposited on the surface of specimens in the test group. Then the sixteen titanium-porcelain specimens were prepared in a rectangular shape and went through three-point bending test on a universal test machine. The bond strength of Ti/porcelain was recorded. The phase composition of the specimens was analyzed using X-ray diffraction (XRD). The interface at titanium and porcelain and the titanium surface after debonding were observed with a scanning electron microscopy (SEM) and analyzed using energy depressive spectrum (EDS). New phase of ZrN was found with XRD in the test group. Statistical analysis showed higher bond strength following ZrN surface treatment in the test group [(45.991+/-0.648) MPa] than that in the control group [(29.483+/-1.007) MPa] (P=0.000). Bonded ceramic could be observed in test group, the amount of bonded ceramic was more than that in the control group. No obvious bonded ceramic in control group was found. Magnetron sputtered ZrN can improve bond strength of Ti/Vita titankeramik system significantly.

Improvement of dielectric properties of BLT thin films deposited by magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Besland, M P; Barroy, P R J; Richard-Plouet, M; Tessier, P Y; Brohan, L; Djouadi, M A [Universite de Nantes - Institut des Materiaux Jean Rouxel, UMR CNRS 6502, 2, rue de la Houssiniere BP32229, 44322 Nantes Cedex (France); Borderon, C; Tacon, S Le; Averty, D; Gundel, H W [Institut de Recherche en Electrotechnique et Electronique de Nantes Atlantique, UPRES-EA 1770, IREENA, Universite de Nantes, 2, rue de la Houssiniere, BP 92208, 44322 Nantes Cedex (France)], E-mail: Marie-Paule.Besland@cnrs-imn.fr

2008-01-15

Well crystallized BLT thin films were deposited by RF magnetron sputtering using a target of Aurivillius phase Bi{sub 3.25}La{sub 0.75}Ti{sub 3}O{sub 12}(BLT{sub 0,75}), elaborated in our institute. RF sputtering experiments were performed at room temperature with an argon/oxygen mixture, in a pressure range of 20-50 mTorr. Optimisation of the plasma parameters, namely deposition pressure, RF power and oxygen content in the gas phase, allows obtaining BLT films with a chemical composition close to Bi{sub 3.25}La{sub 0.75}Ti{sub 3}O{sub 12}. After ex-situ annealing under oxygen atmosphere at 650 deg. C, BLT films deposited on Pt/TiO{sub 2}/SiO{sub 2}/Si (multilayer) substrates exhibit well defined rod-like grains morphology. A two step deposition process appeared to be necessary in order to reach satisfying dielectric properties. The effect of the plasma parameters on the chemical composition and electrical properties are presented and discussed.

Transient Response in Monolithic Mach-Zehnder Optical Modulator Using (Ba,Sr)TiO3 Film Sputtered at Low Temperature on Silicon

Science.gov (United States)

Suzuki, Masato; Nagata, Kazuma; Tanushi, Yuichiro; Yokoyama, Shin

2007-04-01

We have fabricated Mach-Zhender interferometers (MZIs) using the (Ba,Sr)TiO3 (BST) film sputter-deposited at 450 °C, which is a critical temperature for the process after metallization. An optical modulation of about 10% is achieved when 200 V is applied (electric field in BST is 1.2× 104 V/cm). However, the response time of optical modulation to step function voltage is slow (1.0-6.3 s). We propose a model for the slow transient behavior based on movable ions and a long dielectric relaxation time for the BST film, and good qualitative agreement is obtained with experimental results.

TiO2 nanotube formation by Ti film anodization and their transport properties for dye-sensitized solar cells

NARCIS (Netherlands)

Iraj, M.; Kolahdouz, M.; Asl-Soleimani, E.; Esmaeili, E.; Kolahdouz Esfahani, Z.

2016-01-01

In this paper, we present the synthesis of TiO2 nanotube (NT) arrays formed by anodization of Ti film deposited on a fluorine-doped tin oxide-coated glass substrate by direct current magnetron sputtering. NH4F/ethylene glycol electrolyte was used to demonstrate the growth of stable nanotubes at room

Ion beam analysis, corrosion resistance and nanomechanical properties of TiAlCN/CN{sub x} multilayer grown by reactive magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Alemón, B.; Flores, M. [Departamento de Ingeniería de Proyectos, CUCEI, Universidad de Guadalajara, J. Guadalupe Zuno 48, Los Belenes, Zapopan, Jal. 45101 (Mexico); Canto, C. [Instituto de Física, UNAM, Avenida de la Investigación S/N, Coyoacán, Mexico, DF 04510 (Mexico); Andrade, E., E-mail: andrade@fisica.unam.mx [Instituto de Física, UNAM, Avenida de la Investigación S/N, Coyoacán, Mexico, DF 04510 (Mexico); Lucio, O.G. de [Instituto de Física, UNAM, Avenida de la Investigación S/N, Coyoacán, Mexico, DF 04510 (Mexico); Rocha, M.F. [ESIME-Z, Instituto Politécnico Nacional, ALM Zacatenco, Mexico, DF 07738 (Mexico); Broitman, E. [Thin Films Physics Division, IFM, Linköping University, SE-58183 Linköping (Sweden)

2014-07-15

A novel TiAlCN/CN{sub x} multilayer coating, consisting of nine TiAlCN/CN{sub x} periods with a top layer 0.5 μm of CN{sub x}, was designed to enhance the corrosion resistance of CoCrMo biomedical alloy. The multilayers were deposited by dc and RF reactive magnetron sputtering from Ti{sub 0.5}Al{sub 0.5} and C targets respectively in a N{sub 2}/Ar plasma. The corrosion resistance and mechanical properties of the multilayer coatings were analyzed and compared to CoCrMo bulk alloy. Ion beam analysis (IBA) and X-ray diffraction tests were used to measure the element composition profiles and crystalline structure of the films. Corrosion resistance was evaluated by means of potentiodynamic polarization measurements using simulated body fluid (SBF) at typical body temperature and the nanomechanical properties of the multilayer evaluated by nanoindentation tests were analyzed and compared to CoCrMo bulk alloy. It was found that the multilayer hardness and the elastic recovery are higher than the substrate of CoCrMo. Furthermore the coated substrate shows a better general corrosion resistance than that of the CoCrMo alloy alone with no observation of pitting corrosion.

TEM characterization of a Cr/Ti/TiC graded interlayer for magnetron-sputtered TiC/a-C:H nanocomposite coatings

International Nuclear Information System (INIS)

Galvan, D.; Pei, Y.T.; De Hosson, J.Th.M.

2005-01-01

A TiC/a-C:H nanocomposite coating is deposited on top of a Cr/Ti/TiC graded interlayer. Cross-section transmission electron microscopy is employed to investigate the detailed structure of the interlayer and the coating. Five different phases are formed as a consequence of the compositional gradient within the interlayer: pure Cr, a solid solution of Ti in Cr, a Ti/Cr amorphous/nanocrystalline phase, α-Ti and TiC. Solid state amorphization occurs during the interlayer deposition to give a dispersion of TiCr β-phase nanocrystals in an amorphous matrix. The TiC phase is textured and contains numerous stacking faults as a result of the growth in under-stoichiometric carbon concentration. C-enriched columnar boundaries are present within the coating, originating from the TiC column boundaries of the interlayer. The work indicates that an interlayer of amorphous/nanocrystalline Ti/Cr phase would reduce the presence of growth defects such as columnar boundaries within nanocomposite TiC/a-C:H coatings

Plasma analysis of inductively coupled impulse sputtering of Cu, Ti and Ni

Science.gov (United States)

Loch, D. A. L.; Aranda Gonzalvo, Y.; Ehiasarian, A. P.

2017-06-01

Inductively coupled impulse sputtering (ICIS) is a new development in the field of highly ionised pulsed PVD processes. For ICIS the plasma is generated by an internal inductive coil, replacing the need for a magnetron. To understand the plasma properties, measurements of the current and voltage waveforms at the cathode were conducted. The ion energy distribution functions (IEDFs) were measured by energy resolved MS and plasma chemistry was analysed by OES and then compared to a model. The target was operated in pulsed DC mode and the coil was energised by pulsed RF power, with a duty cycle of 7.5%. At a constant pressure (14 Pa) the set peak RF power was varied from 1000-4000 W. The DC voltage to the target was kept constant at 1900 V. OES measurements have shown a monotonic increase in intensity with increasing power. Excitation and ionisation processes were single step for ICIS of Ti and Ni and multi-step for Cu. The latter exhibited an unexpectedly steep rise in ionisation efficiency with power. The IEDFs measured by MS show the material- and time-dependant plasma potential in the range of 10-30 eV, ideal for increased surface mobility without inducing lattice defects. A lower intensity peak, of high energetic ions, is visible at 170 eV during the pulse.

Interdiffusion within model TiN/Cu and TiTaN/Cu systems synthesized by combinatorial thin film deposition

International Nuclear Information System (INIS)

Mühlbacher, M.

2015-01-01

Continued device miniaturization in microelectronics calls for a fundamental understanding of diffusion processes and damage mechanisms in the Cu metallization/TiN barrier layer system. Thus, the starting point of the present study is a combined experimental and theoretical examination of lattice diffusion in ideal single-crystal TiN/Cu stacks grown on MgO(001) by unbalanced DC magnetron sputter deposition. After a 12 h annealing treatment at 1000 °C, a uniform Cu diffusion layer of 7-12 nm is observed by scanning transmission electron microscopy and atom probe tomography (APT). Density-functional theory calculations predict a stoichiometry-dependent atomic diffusion mechanism of Cu in bulk TiN, with Cu diffusing on the N sublattice for the experimental N/Ti ratio of 0.92. These findings are extended to a comparison of grain boundary diffusion of Cu in dense polycrystalline TiN sputter-deposited on Si at 700 °C and underdense polycrystalline TiN grown on Si without external substrate heating. While the Cu diffusion path along dense TiN grain boundaries can be restricted to approximately 30 nm after a 1 h annealing treatment at 900 °C as visualized by 3D APT reconstructions, it already exceeds 500 nm after annealing at 700 °C in the underdense low-temperature TiN barrier. In this case, the formation of the Cu3Si phase, which characteristically grows along the close-packed directions in Si, is identified as the main damage mechanism leading to complete barrier failure. To meet the low-temperature processing needs of semiconductor industry and at the same time exploit the improved performance of dense polycrystalline barrier layers, deposition of TiTaN barriers on Si is demonstrated by a reactive hybrid high-power impulse/DC magnetron sputtering process, where barrier densification is achieved by pulsed irradiation of the growth surface with only a few at.% of energetic Ta ions without external substrate heating. These barrier layers delay the onset of Cu grain

NiTiCu/AlN/NiTiCu shape memory thin film heterostructures for vibration damping in MEMS

Energy Technology Data Exchange (ETDEWEB)

Kaur, Navjot; Kaur, Davinder, E-mail: dkaurfph@iitr.ernet.in

2014-03-25

Highlights: • Fabrication of NiTiCu/AlN/NiTiCu heterostructure using dc/rf magnetron sputtering. • Exhibits highest hardness (38 GPa) and elastic modulus (187 GPa). • Enhanced dissipation of mechanical energy (E{sub d} = 5.7 N J). • High damping capacity (0.052) and figure of merit (∼0.62). • Can be applied for vibration damping in MEMS. -- Abstract: Shape memory alloy (NiTiCu) thin films coupled with piezoelectric AlN layer produce an intelligent material for vibration damping. In the present study pure NiTiCu, NiTiCu/AlN and NiTiCu/AlN/NiTiCu heterostructures have been deposited on Si substrate using magnetron sputtering technique. By the use of the interfaces and shape memory effect provided by NiTiCu layers, the damping capacity can be increased along with increase in stiffness and mechanical hardness. The heterostructures were characterized in terms of structural, electrical, morphological and mechanical properties by X-ray diffraction (XRD), four probe resistivity method, atomic force microscopy, field emission scanning electron microscopy, and nanoindentation. The NiTiCu/AlN/NiTiCu heterostructure exhibit enhanced mechanical and damping properties as compared to NiTiCu/AlN and pure NiTiCu. This enhancement in hardness and damping of the heterostructure could be attributed to the shape memory effect of NiTiCu, intrinsic piezoelectricity of AlN and increased number of interfaces in heterostructure that help in dissipation of mechanical vibrations. The findings of this work provide additional impetus for the application of these heterostructures in emerging fields of nanotechnology and microelectro mechanical (MEMS) devices.

NiTiCu/AlN/NiTiCu shape memory thin film heterostructures for vibration damping in MEMS

International Nuclear Information System (INIS)

Kaur, Navjot; Kaur, Davinder

2014-01-01

Highlights: • Fabrication of NiTiCu/AlN/NiTiCu heterostructure using dc/rf magnetron sputtering. • Exhibits highest hardness (38 GPa) and elastic modulus (187 GPa). • Enhanced dissipation of mechanical energy (E d = 5.7 N J). • High damping capacity (0.052) and figure of merit (∼0.62). • Can be applied for vibration damping in MEMS. -- Abstract: Shape memory alloy (NiTiCu) thin films coupled with piezoelectric AlN layer produce an intelligent material for vibration damping. In the present study pure NiTiCu, NiTiCu/AlN and NiTiCu/AlN/NiTiCu heterostructures have been deposited on Si substrate using magnetron sputtering technique. By the use of the interfaces and shape memory effect provided by NiTiCu layers, the damping capacity can be increased along with increase in stiffness and mechanical hardness. The heterostructures were characterized in terms of structural, electrical, morphological and mechanical properties by X-ray diffraction (XRD), four probe resistivity method, atomic force microscopy, field emission scanning electron microscopy, and nanoindentation. The NiTiCu/AlN/NiTiCu heterostructure exhibit enhanced mechanical and damping properties as compared to NiTiCu/AlN and pure NiTiCu. This enhancement in hardness and damping of the heterostructure could be attributed to the shape memory effect of NiTiCu, intrinsic piezoelectricity of AlN and increased number of interfaces in heterostructure that help in dissipation of mechanical vibrations. The findings of this work provide additional impetus for the application of these heterostructures in emerging fields of nanotechnology and microelectro mechanical (MEMS) devices

Electrochemical characterization of V{sub x}Nb{sub y}C{sub z}/Bi{sub x}Ti{sub y}O{sub z} coatings produced through thermo-reactive diffusion and the sputtering technique

Energy Technology Data Exchange (ETDEWEB)

Castro H, S. A.; Alfonso, J. E.; Olaya, J. J., E-mail: jealfonso@unal.edu.co [Universidad Nacional de Colombia, Departamento de Fisica, Grupo de Ciencia de Materiales y Superficies, AA-14490 Bogota (Colombia)

2016-11-01

We present and experimental study of the structural evolution of a bilayer V{sub x}Nb{sub y}C{sub z}/Bi{sub x}Ti{sub y}O{sub z} coating produced via thermo-reactive diffusion (TRD) and the RF sputtering process on D-2 steel substrate. The TRD treatments were carried out in a molten mixture consisting of borax, ferro-niobium, ferro-vanadium, and aluminum, at 1313 K for 3 hours, using a resistance-heating furnace. Bi{sub x}Ti{sub y}O{sub z} coatings were deposited using RF magnetron sputtering on TRD coatings, in order to carry out a study of the corrosion behavior of this compound. The crystallographic structure of the coatings was determined via X-ray diffraction, the corrosion resistance was analyzed through the potentiodynamic polarization test (Tafel Extrapolation) and electrochemical impedance spectroscopic analysis (EIS). X-ray diffraction patterns showed that the ternary coating (VNbC{sub 2}) was preferentially oriented along the [200] direction with a cubic-centered face structure, and the Bi{sub x}Ti{sub y}O{sub z} coatings were amorphous. The electrochemical studies showed that the resistance corrosion of the coatings increased with respect to the bare substrate, and that polarization resistance in the bilayer coatings increased with respect to the ternary coatings, suggesting that the titanate has anti corrosive barrier effects. (Author)

Influence of an elevated nutrition risk score (NRS) on survival in patients following gastrectomy for gastric cancer.

Science.gov (United States)

Bachmann, J; Müller, T; Schröder, A; Riediger, C; Feith, M; Reim, D; Friess, H; Martignoni, M E

2015-07-01

In the last years, the impact of weight loss in patients with malignant tumors has come more and more into the focus of clinical research, as the occurrence of weight loss is often associated with a reduced survival. Weight loss can be a hint for metastases in patients suffering from malignant tumors; furthermore, these patients are usually not able to be treated with chemotherapy. The aim of the study was to show the influence of weight loss and an elevated nutrition risk score on survival following tumor resection in patients suffering from gastric cancer. In 99 patients in whom a gastrectomy due to gastric cancer was performed, the nutrition risk score was calculated and its influence on mortality, morbidity and survival was analyzed. Of the included patients, 45 % of the patients gave a history of weight loss; they had significantly more often a NRS ≥ 3. In UICC stage 1a/b, a NRS ≥ 3 was associated with a significantly reduced survival compared to patients with a NRS gastric cancer, the influence of a reduced NRS is negligible.

Ammonia Sensing Behaviors of TiO2-PANI/PA6 Composite Nanofibers

Directory of Open Access Journals (Sweden)

Fenglin Huang

2012-12-01

Full Text Available Titanium dioxide-polyaniline/polyamide 6 (TiO2-PANI/PA6 composite nanofibers were prepared by in situ polymerization of aniline in the presence of PA6 nanofibers and a sputtering-deposition process with a high purity titanium sputtering target. TiO2-PANI/PA6 composite nanofibers and PANI/PA6 composite nanofibers were fabricated for ammonia gas sensing. The ammonia sensing behaviors of the sensors were examined at room temperature. All the results indicated that the ammonia sensing property of TiO2-PANI/PA6 composite nanofibers was superior to that of PANI/PA6 composite nanofibers. TiO2-PANI/PA6 composite nanofibers had good selectivity to ammonia. It was also found that the content of TiO2 had a great influence on both the morphology and the sensing property of TiO2-PANI/PA6 composite nanofibers.

Controllable Charge Transfer in Ag-TiO2 Composite Structure for SERS Application

Directory of Open Access Journals (Sweden)

Yaxin Wang

2017-06-01

Full Text Available The nanocaps array of TiO2/Ag bilayer with different Ag thicknesses and co-sputtering TiO2-Ag monolayer with different TiO2 contents were fabricated on a two-dimensional colloidal array substrate for the investigation of Surface enhanced Raman scattering (SERS properties. For the TiO2/Ag bilayer, when the Ag thickness increased, SERS intensity decreased. Meanwhile, a significant enhancement was observed when the sublayer Ag was 10 nm compared to the pure Ag monolayer, which was ascribed to the metal-semiconductor synergistic effect that electromagnetic mechanism (EM provided by roughness surface and charge-transfer (CT enhancement mechanism from TiO2-Ag composite components. In comparison to the TiO2/Ag bilayer, the co-sputtered TiO2-Ag monolayer decreased the aggregation of Ag particles and led to the formation of small Ag particles, which showed that TiO2 could effectively inhibit the aggregation and growth of Ag nanoparticles.

H2O2 sensing using HRP modified catalyst-free ZnO nanorods synthesized by RF sputtering

Science.gov (United States)

Srivastava, Amit; Kumar, Naresh; Singh, Priti; Singh, Sunil Kumar

2017-06-01

Catalyst-free ( 00 l) oriented ZnO nanorods (NRs) -based biosensor for the H2O2 sensing has been reported. The (002) oriented ZnO NRs as confirmed by X-ray diffraction were successfully grown on indium tin oxide (ITO) coated glass substrate by radio frequency (RF) sputtering technique without using any catalyst. Horseradish peroxidase (HRP) enzyme was immobilized on ZnO NRs by physical adsorption technique to prepare the biosensor. In this HRP/ZnO NR/ITO bioelectrode, nafion solution was added to form a tight membrane on surface. The prepared bioelectrode has been used for biosensing measurements by electrochemical analyzer. The electrochemical studies reveal that the prepared HRP/ZnO NR/ITO biosensor is highly sensitive to the detection of H2O2 over a linear range of 0.250-10 μM. The ZnO NR-based biosensor showed lower value of detection limit (0.125 μM) and higher sensitivity (13.40 µA/µM cm2) towards H2O2. The observed value of higher sensitivity attributed to larger surface area of ZnO nanostructure for effective loading of HRP besides its high electron communication capability. In addition, the biosensor also shows lower value of enzyme's kinetic parameter (Michaelis-Menten constant, K m) of 0.262 μM which indicates enhanced enzyme affinity of HRP to H2O2. The reported biosensor may be useful for various applications in biosensing, clinical, food, and beverage industry.

Influence of substrate bias voltage on the properties of TiO{sub 2} deposited by radio-frequency magnetron sputtering on 304L for biomaterials applications

Energy Technology Data Exchange (ETDEWEB)

Bait, L. [Division Milieux Ionisés et Lasers, Centre de Développement des Technologies Avancées, CDTA,Cité du 20 aout 1956, Baba Hassen, BP n°. 17, Alger (Algeria); Azzouz, L. [Université de Amar Telidji, Laghouat (Algeria); Madaoui, N. [Division Milieux Ionisés et Lasers, Centre de Développement des Technologies Avancées, CDTA,Cité du 20 aout 1956, Baba Hassen, BP n°. 17, Alger (Algeria); Saoula, N., E-mail: nsaoula@cdta.dz [Division Milieux Ionisés et Lasers, Centre de Développement des Technologies Avancées, CDTA,Cité du 20 aout 1956, Baba Hassen, BP n°. 17, Alger (Algeria)

2017-02-15

Highlights: • TiO{sub 2} films were deposited on stainless steel 304L RF magnetron sputtering at different substrate bias. • The hardness of TiO{sub 2} coated 304L are higher than those obtained for uncoated substrate. • TiO{sub 2} films provide good protection for stainless steel against corrosion in Ringer solution. - Abstract: The aim of this paper is to investigate the effect of the substrate bias, varied from 0 to −100 V, on the structure and properties of the TiO{sub 2} thin films for biomaterials applications. The TiO{sub 2} films were grown onto 304L stainless steel substrate using radio-frequency (rf) magnetron sputtering from a pure titanium target in Ar-O{sub 2} gas mixture. The variation of substrate bias voltage from 0 to −100 V produces variations of structure and mechanical properties of the films. The deposited films were characterized by X-rays diffraction, nanoindentation and potentiodynamic polarization. Also, the friction and wear properties of TiO{sub 2} films sliding against alumina ball in air were investigated. Experimental results showed that the thickness increases for non-biased substrate voltage to Vs = −100 V from 820 nm to 1936 nm respectively. The roughness is in the range of 50 nm and 14 nm. XRD results show that all structures of the films are crystalline and changed with varying the bias voltage. The anatase phase is predominant in the low negative bias range (0–50 V). The hardness significantly increased from 2.2 to 6.4 GPa when the bias voltage was increased from 0 to 75 V and then slightly decrease to 5.1 GPa as further increased to 100 V. At the same time, the results indicate that TiO{sub 2} films deposited at −100 V exhibited better wear resistance compared to the other samples, i.e. the minimum wear rates and the lower coefficient of friction of 0.16. In order to simulate natural biological conditions, physiological serum (pH = 6.3), thermostatically controlled at 37 °C, was used as the electrolyte for the

Improving the Tribological Properties of Spark-Anodized Titanium by Magnetron Sputtered Diamond-Like Carbon

OpenAIRE

Zhaoxiang Chen; Xipeng Ren; Limei Ren; Tengchao Wang; Xiaowen Qi; Yulin Yang

2018-01-01

Spark-anodization of titanium can produce adherent and wear-resistant TiO2 film on the surface, but the spark-anodized titanium has lots of surface micro-pores, resulting in an unstable and high friction coefficient against many counterparts. In this study, the diamond-like carbon (DLC) was introduced into the micro-pores of spark-anodized titanium by the magnetron sputtering technique and a TiO2/DLC composite coating was fabricated. The microstructure and tribological properties of TiO2/DLC ...

Effects of TiN coating on the corrosion of nanostructured Ti-30Ta-xZr alloys for dental implants

Science.gov (United States)

Kim, Won-Gi; Choe, Han-Cheol

2012-01-01

Electrochemical characteristics of a titanium nitride (TiN)-coated/nanotube-formed Ti-Ta-Zr alloy for biomaterials have been researched by using the magnetic sputter and electrochemical methods. Ti-30Ta-xZr (x = 3, 7 and 15 wt%) alloys were prepared by arc melting and heat treated for 24 h at 1000 °C in an argon atmosphere and then water quenching. The formation of oxide nanotubes was achieved by anodizing a Ti-30Ta-xZr alloy in H3PO4 electrolytes containing small amounts of fluoride ions at room temperature. Anodization was carried out using a scanning potentiostat, and all experiments were conducted at room temperature. The microstructure and morphology of nanotube arrays were characterized by optical microscopy (OM), field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD). The TiN coatings were obtained by the radio-frequency (RF) magnetron sputtering technique. The depositions were performed from pure Ti targets on Ti-30Ta-xZr alloys substrates. The corrosion properties of the specimens were examined using potentiodynamic test in a 0.9% NaCl solution by using potentiostat. The microstructures of Ti-30Ta-xZr alloys were changed from an equiaxed to a needle-like structure with increasing Zr content. The interspace between the nanotubes was approximately 20, 80 and 200 nm for Zr contents of 3, 7 and 15 wt%, respectively. The corrosion resistance of the TiN-coated on the anodized Ti-30Ta-xZr alloys was higher than that of the untreated Ti alloys, indicating a better protective effect.

Substantial difference in target surface chemistry between reactive dc and high power impulse magnetron sputtering

Science.gov (United States)

Greczynski, G.; Mráz, S.; Schneider, J. M.; Hultman, L.

2018-02-01

The nitride layer formed in the target race track during the deposition of stoichiometric TiN thin films is a factor 2.5 thicker for high power impulse magnetron sputtering (HIPIMS), compared to conventional dc processing (DCMS). The phenomenon is explained using x-ray photoelectron spectroscopy analysis of the as-operated Ti target surface chemistry supported by sputter depth profiles, dynamic Monte Carlo simulations employing the TRIDYN code, and plasma chemical investigations by ion mass spectrometry. The target chemistry and the thickness of the nitride layer are found to be determined by the implantation of nitrogen ions, predominantly N+ and N2+ for HIPIMS and DCMS, respectively. Knowledge of this method-inherent difference enables robust processing of high quality functional coatings.

Titanium dioxide fine structures by RF magnetron sputter method deposited on an electron-beam resist mask

Science.gov (United States)

Hashiba, Hideomi; Miyazaki, Yuta; Matsushita, Sachiko

2013-09-01

Titanium dioxide (TiO2) has been draw attention for wide range of applications from photonic crystals for visible light range by its catalytic characteristics to tera-hertz range by its high refractive index. We present an experimental study of fabrication of fine structures of TiO2 with a ZEP electron beam resist mask followed by Ti sputter deposition techniques. A TiO2 thin layer of 150 nm thick was grown on an FTO glass substrate with a fine patterned ZEP resist mask by a conventional RF magnetron sputter method with Ti target. The deposition was carried out with argon-oxygen gases at a pressure of 5.0 x 10 -1 Pa in a chamber. During the deposition, ratio of Ar-O2 gas was kept to the ratio of 2:1 and the deposition ratio was around 0.5 Å/s to ensure enough oxygen to form TiO2 and low temperature to avoid deformation of fine pattern of the ZPU resist mask. Deposited TiO2 layers are white-transparent, amorphous, and those roughnesses are around 7 nm. Fabricated TiO2 PCs have wider TiO2 slabs of 112 nm width leaving periodic 410 x 410 nm2 air gaps. We also studied transformation of TiO2 layers and TiO2 fine structures by baking at 500 °C. XRD measurement for TiO2 shows that the amorphous TiO2 transforms to rutile and anatase forms by the baking while keeping the same profile of the fine structures. Our fabrication method can be one of a promising technique to optic devices on researches and industrial area.

Enhanced supercapacitor performance using hierarchical TiO2 nanorod/Co(OH)2 nanowall array electrodes

International Nuclear Information System (INIS)

Ramadoss, Ananthakumar; Kim, Sang Jae

2014-01-01

Graphical abstract: - Highlights: • TiO 2 /Co(OH) 2 hierarchical nanostructure was prepared by a combination of hydrothermal and cathodic electrodeposition method. • Hierarchical nanostructure electrode exhibited a maximum capacitance of 274.3 mF cm −2 at a scan rate of 5 mV s −1 . • Combination of Co(OH) 2 nanowall with TiO 2 NR into a single system enhanced the electrochemical behavior of supercapacitor electrode. - Abstract: We report novel hierarchical TiO 2 nanorod (NR)/porous Co(OH) 2 nanowall array electrodes for high-performance supercapacitors fabricated using a two-step process that involves hydrothermal and electrodeposition techniques. Field-emission scanning electron microscope images reveal a bilayer structure consisting of TiO 2 NR arrays with porous Co(OH) 2 nanowalls. Compared with the bare TiO 2 NRs, the hierarchical TiO 2 NRs/Co(OH) 2 electrodes showed improved pseudocapacitive performance in a 2-M KOH electrolyte solution, exhibiting an areal specific capacitance of 274.3 mF cm −2 at a scan rate of 5 mV s −1 . The electrodes exhibited good stability, retaining 82.5% of the initial capacitance after 4000 cycles. The good pseudocapacitive performance of the hierarchical nanostructures is mainly due to the porous structure, which provides fast ion and electron transfer, a large surface area, short ion diffusion paths, and a favourable volume change during the cycling process

Effect of electroless nickel interlayer on the electrochemical behavior of single layer CrN, TiN, TiAlN coatings and nanolayered TiAlN/CrN multilayer coatings prepared by reactive dc magnetron sputtering

International Nuclear Information System (INIS)

Grips, V.K. William; Ezhil Selvi, V.; Barshilia, Harish C.; Rajam, K.S.

2006-01-01

The electrochemical behavior of single layer TiN, CrN, TiAlN and multilayer TiAlN/CrN coatings, deposited on steel substrates using a multi-target reactive direct current (dc) magnetron sputtering process, was studied in 3.5% NaCl solution. The total thickness of the coatings was about 1.5 μm. About 0.5 μm thick chromium interlayer was used to improve adhesion of the coatings. With an aim to improve the corrosion resistance, an additional interlayer of approximately 5 μm thick electroless nickel (EN) was deposited on the substrate. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) were used to study the corrosion behavior of the coatings. Scanning electron microscopy and energy dispersive X-ray analysis were used to characterize the corroded samples. The potentiodynamic polarization tests showed lower corrosion current density and higher polarization resistance (R p ) for the coatings with EN interlayer. For example, the corrosion current density of TiN coated steel was decreased by a factor of 10 by incorporating 5 μm thick EN interlayer. Similarly, multilayer coatings of TiAlN/CrN with EN interlayer showed about 30 times improved corrosion resistance as compared to the multilayers without EN interlayer. The porosity values were calculated from the potentiodynamic polarization data. The Nyquist and the Bode plots obtained from the EIS data were fitted by appropriate equivalent circuits. The pore resistance (R pore ), the charge transfer resistance (R ct ), the coating capacitance (Q coat ) and the double layer capacitance (Q dl ) of the coatings were obtained from the equivalent circuit. Multilayer coatings showed higher R pore and R ct values as compared to the single layer coatings. Similarly, the Q coat and Q dl values decreased from uncoated substrate to the multilayer coatings, indicating a decrease in the defect density by the addition of EN interlayer. These studies were confirmed by examining the corroded samples under

Structural evolution of Ti/TiC multilayers

International Nuclear Information System (INIS)

Dahan, I.; Frage, N.; Dariel, M.P.

2004-01-01

Hard coatings based on metal/ceramic multilayers with periods in the nanometer range have been shown to possess some potential for improved tribological and mechanical properties. The present work is concerned with the structural evolution of (Ti/TiC) multilayers. Two kinds of multilayers consisting of 30 equithick (40 nm)TiC layers and 20 and 60 nm thick Ti layers, respectively, were sputter deposited on Mo substrates. The structural and the compositional evolution of these multilayers were examined by x-ray diffraction, transition electron microscopy (TEM), high-resolution TEM, Auger electron microscopy spectroscopy and differential thermal analysis (DTA), in the as-deposited state and after various heat treatments up to 500 deg. C. Initially, the Ti layers had a crystalline columnar grain structure displaying a (002) texture. The TiC layers displayed weak crystallinity with a pronounced (111) texture. In the course of the heat treatments, carbon diffused from the carbide layer into the adjacent Ti layers transforming the latter into off-stoichiometric TiC x with x≅0.5 and simultaneously depleting the carbon content of the initial carbide layer. The formed TiC x layers maintained the textural relationship with the neighboring TiC layers, consistent with a transformation that involved only a ABAB to ABC stacking change of the Ti sublattice. Increased mobility of the Ti atoms in carbon-depleted original TiC layers led to their full or partial recrystallization. The thermal effects associated both with the transformation of Ti layers into TiC, due to the influx of carbon atoms, and with the recrystallization of the original TiC layers were clearly revealed by the DTA measurements

Titanium dioxide (TIO2) thin film and plasma properties in RF magnetron sputtering

International Nuclear Information System (INIS)

Ali, Riyaz Ahmad Mohamed; Nayan, Nafarizal

2013-01-01

Lately, titanium dioxide (TiO 2 ) films with anatase crystalline property received numerous attentions as unique material properties. There are wide applications of TiO 2 thin film such as for photocatalytic application in solar cell. In the present study, radio frequency (RF) magnetron sputtering technique has been used to produce high dense, homogeneously controllable film layer at low deposition temperature using titanium (Ti) target. The diameter of the Ti target is 3 inch with fixed discharge power of 400W. Magnetron sputtering plasma has been produced in high purity 99.99% Argon (Ar) and 99.99% Oxygen (O 2 ) environment pressure ranging from 5 to 20 mTorr. The TiO2 were growth on silicon and glass substrates. Substrate temperature during deposition was kept constant at 400°C. The distance between target and substrate holder was maintain at 14 cm with rotation of 10 rotation-per-minutes. Our X-ray diffraction result, shows anatase crystalline successfully formed with characterization peaks of plane (101) at 2θ = 25.28°, plane (202) at 2θ = 48.05° and plane (211) at 2θ = 55.06°. In addition, it is our interest to study the plasma properties and optical spectrum of Ti, Ti+ , O- , ArM and Ar+ in the chamber during the deposition process. Result of emission line intensities, electron density and temperature from optical spectroscope and Langmuir probe will be discuss further during the workshop. This works were supported by Graduate Incentive Scheme of Universiti Tun Hussein Onn Malaysia (UTHM) and Fundamental Research Grant Scheme of Ministry of Higher Education, Malaysia. (author)

Chemical Bonding States of TiC Films before and after Hydrogen Ion Irradiation

Institute of Scientific and Technical Information of China (English)

无

2007-01-01

TiC films deposited by rf magnetron sputtering followed by Ar+ ion bombardment were irradiated with a hydrogen ion beam. X-ray photoelectron spectroscopy (XPS) was used for characterization of the chemical bonding states of C and Ti elements of the TiC films before and after hydrogen ion irradiation, in order to understand the effect of hydrogen ion irradiation on the films and to study the mechanism of hydrogen resistance of TiC films. Conclusions can be drawn that ion bombardment at moderate energy can cause preferential physical sputtering of carbon atoms from the surface of low atomic number (Z) material. This means that ion beam bombardment leads to the formation of a non-stoichiometric composition of TiC on the surface.TiC films prepared by ion beam mixing have the more excellent characteristic of hydrogen resistance. One important cause, in addition to TiC itself, is that there are many vacant sites in TiC created by ion beam mixing.These defects can easily trap hydrogen and effectively enhance the effect of hydrogen resistance.

The microstructure and properties of titanium dioxide films synthesized by unbalanced magnetron sputtering

International Nuclear Information System (INIS)

Leng, Y.X.; Chen, J.Y.; Yang, P.; Sun, H.; Huang, N.

2007-01-01

In this work, titanium oxide films were deposited on Ti6Al4V and Si (1 0 0) by DC unbalanced magnetron sputtering method at different oxygen pressure. X-ray diffraction (XRD), microhardness tests, pin-on-disk wear experiments, surface contact angle tests and platelet adhesion investigation were conducted to evaluate the properties of the films. The corrosion behavior of titanium dioxide films was characterized by potentiodynamic polarization. The results showed that titanium oxide films deposited by unbalance magnetron sputtering were compact and could obviously enhance microhardness, wear resistance of titanium alloy substrate. Potentiodynamic polarization curves showed that Ti-6Al-4V deposited with titanium dioxide films had lower dissolution currents than that of the uncoated one. The results of in vitro hemocompatibility analyses indicated that the blood compatibility of the titanium dioxide films with bandgap 3.2 eV have better blood compatibility

Radiolysis and sputtering of carbon dioxide ice induced by swift Ti, Ni, and Xe ions

Energy Technology Data Exchange (ETDEWEB)

Mejía, C. [Centre de Recherche sur les Ions, les Matériaux et la Photonique CIMAP (CEA-CNRS-ENSICAEN-UCN), CIMAP-Ganil, BP 5133, Boulevard Henri Becquerel, 14070 Caen Cedex 05 (France); Departamento de Física, Pontifícia Universidade Católica do Rio de Janeiro, Rua Marquês de São Vicente 225, 22453-900 Rio de Janeiro, RJ (Brazil); Bender, M.; Severin, D. [Materials Research Department, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt (Germany); Trautmann, C. [Materials Research Department, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt (Germany); Technische Universität, 64287 Darmstadt (Germany); Boduch, Ph. [Centre de Recherche sur les Ions, les Matériaux et la Photonique CIMAP (CEA-CNRS-ENSICAEN-UCN), CIMAP-Ganil, BP 5133, Boulevard Henri Becquerel, 14070 Caen Cedex 05 (France); Bordalo, V. [Centre de Recherche sur les Ions, les Matériaux et la Photonique CIMAP (CEA-CNRS-ENSICAEN-UCN), CIMAP-Ganil, BP 5133, Boulevard Henri Becquerel, 14070 Caen Cedex 05 (France); Observatório Nacional-MCTI, Rua General José Cristino 77, 20921-400 Rio de Janeiro, RJ (Brazil); Domaracka, A.; Lv, X.Y. [Centre de Recherche sur les Ions, les Matériaux et la Photonique CIMAP (CEA-CNRS-ENSICAEN-UCN), CIMAP-Ganil, BP 5133, Boulevard Henri Becquerel, 14070 Caen Cedex 05 (France); and others

2015-12-15

Solid carbon dioxide (CO{sub 2}) is found in several bodies of the solar system, the interstellar medium (ISM) and young stellar objects, where it is exposed to cosmic and stellar wind radiation. Here, the chemical and physical modifications induced by heavy ion irradiation of pure solid CO{sub 2} at low temperature (T = 15–30 K) are analyzed. The experiments were performed with Ti (550 MeV) and Xe (630 MeV) ions at the UNILAC of GSI/Darmstadt and with Ni ions (46 and 52 MeV) at IRRSUD of GANIL/Caen. The evolution of the thin CO{sub 2} ice films (deposited on a CsI window) was monitored by mid-infrared absorption spectroscopy (FTIR). The dissociation rate of CO{sub 2}, determined from the fluence dependence of the IR absorption peak intensity, is found to be proportional to the electronic stopping power S{sub e}. We also confirm that the sputtering yield shows a quadric increase with electronic stopping power. Furthermore, the production rates of daughter molecules such as CO, CO{sub 3} and O{sub 3} were found to be linear in S{sub e}.

Comportamiento de las herramientas de conformado con recubrimientos TiAlN crecido por Magnetrón Sputtering Tríodo

Directory of Open Access Journals (Sweden)

Diana Marcela Devia-Narváez

2015-01-01

Full Text Available Esta investigación se enfoca en el análisis tribológico de los recubrimientos de nitruro de titanio aluminio (TiAlN depositad os por la técnica Magnetrón Sputtering Tríodo, cuando se utilizan como ca pa protectora en herr amientas de conformado. El análisis se rea liza a partir de las propiedades microestructurales que influyen direc tamente en el comportamiento tribológico. Se observó que los me canismos de desgaste predominantes en la superficie son la delaminación y la tribo-oxidación; se determinó un incremento en la vida úti l de la herramienta siendo lo s recubrimientos duros u na excelente alter nativa en la industria metalmecánica.

Effective charge collection in dye-sensitized nanocrystalline TiO2

Science.gov (United States)

Yanagida, Masatoshi; Numata, Youhei; Yoshimatsu, Keiichi; Satoh, Shin; Han, Liyuan

2013-03-01

The effective charge collection in dye-sensitized solar cells (DSCs) is an important factor to improve the efficiency. Here, we report the comparison of three types of structures in DSCs. One type of structure is a sandwich-type DSC (SW-DSC), in which the TiO2 film is sandwiched between a TCO glass front electron-collection electrode and a sputtered Ti back collection electrode. The second is a normal DSC (N-DSC), which has no back electrode. The third is a back-contact-type DSC (BC-DSC), in which a sputtered Ti back electrode is deposited on a TiO2 film on the opposite side of the normal glass as an optical window. The photocurrent response of an SW-DSC is the fastest of the three structures due to using intensity modulated photocurrent spectroscopy, which can be explained by the electron diffusion model. The model shows that the SW-DSC is a favorable structure for effective charge collection in DSCs.

Effective charge collection in dye-sensitized nanocrystalline TiO2

International Nuclear Information System (INIS)

Yanagida, Masatoshi; Numata, Youhei; Yoshimatsu, Keiichi; Satoh, Shin; Han, Liyuan

2013-01-01

The effective charge collection in dye-sensitized solar cells (DSCs) is an important factor to improve the efficiency. Here, we report the comparison of three types of structures in DSCs. One type of structure is a sandwich-type DSC (SW-DSC), in which the TiO 2 film is sandwiched between a TCO glass front electron-collection electrode and a sputtered Ti back collection electrode. The second is a normal DSC (N-DSC), which has no back electrode. The third is a back-contact-type DSC (BC-DSC), in which a sputtered Ti back electrode is deposited on a TiO 2 film on the opposite side of the normal glass as an optical window. The photocurrent response of an SW-DSC is the fastest of the three structures due to using intensity modulated photocurrent spectroscopy, which can be explained by the electron diffusion model. The model shows that the SW-DSC is a favorable structure for effective charge collection in DSCs. (paper)

Huge increase in gas phase nanoparticle generation by pulsed direct current sputtering in a reactive gas admixture

Science.gov (United States)

Polonskyi, Oleksandr; Peter, Tilo; Mohammad Ahadi, Amir; Hinz, Alexander; Strunskus, Thomas; Zaporojtchenko, Vladimir; Biederman, Hynek; Faupel, Franz

2013-07-01

Using reactive DC sputtering in a gas aggregation cluster source, we show that pulsed discharge gives rise to a huge increase in deposition rate of nanoparticles by more than one order of magnitude compared to continuous operation. We suggest that this effect is caused by an equilibrium between slight target oxidation (during "time-off") and subsequent sputtering of Ti oxides (sub-oxides) at "time-on" with high power impulse.

Characteristics of Ti films for transition-edge sensor microcalorimeters

International Nuclear Information System (INIS)

Ukibe, M.; Koyanagi, M.; Ohkubo, M.; Pressler, H.; Kobayashi, N.

1999-01-01

We are developing X-ray microcalorimeters using superconducting transition-edge sensors (TESs), which can be operated at relatively high base temperatures of a 3 He cryostat. For this purpose, we have selected Ti films to be used as TESs. The Ti films were deposited on different substrates by RF-sputtering. It was found that the superconducting properties of the Ti films depended on Ar pressure, film thickness, and substrate surface roughness

The effect of TiO2 nanocrystal shape on the electrical properties of poly(styrene-b-methyl methacrylate) block copolymer based nanocomposites for solar cell application

International Nuclear Information System (INIS)

Cano, Laida; Gutierrez, Junkal; Di Mauro, A. Evelyn; Curri, M. Lucia; Tercjak, Agnieszka

2015-01-01

Titanium dioxide (TiO 2 ) nanocrystals were synthesized into two shapes, namely spherical and rod-like and used for the fabrication of polystyrene-block-poly(methyl methacrylate) (PSMMA) block copolymer based nanocomposites, which were employed as the active top layer of electro-devices for solar cell application. Electro-devices were designed using nanocomposites with high TiO 2 nanocrystal contents (50-70 wt%) and for comparison as-synthesized TiO 2 nanospheres (TiO 2 NSs) and TiO 2 nanorods (TiO 2 NRs) were also used. The morphology of the electro-devices was studied by atomic force microscopy showing good nanocrystal dispersion. The electrical properties of the devices were investigated by PeakForce tunneling atomic force microscopy and Keithley semiconductor analyzer, which showed higher electrical current values for devices containing TiO 2 NRs in comparison to TiO 2 NSs. Remarkably, the influence of the PSMMA block copolymer on the improvement of the conductivity of the electro-devices was also assessed, demonstrating that the self-assembling ability of block copolymer can be beneficial to improve charge transfer in the fabricated electro-devices, thus representing relevant systems to be potentially developed for photovoltaic applications. Moreover, the absorbance of the prepared electro-devices in solar irradiation range was confirmed by UV–vis spectroscopy characterization.

Thermal oxidation of tungsten-based sputtered coatings

International Nuclear Information System (INIS)

Louro, C.; Cavaleiro, A.

1997-01-01

The effect of the addition of nickel, titanium, and nitrogen on the air oxidation behavior of W-based sputtered coatings in the temperature range 600 to 800 C was studied. In some cases these additions significantly improved the oxidation resistance of the tungsten coatings. As reported for bulk tungsten, all the coatings studied were oxidized by layers following a parabolic law. Besides WO 3 and WO x phases detected in all the oxidized coatings, TiO 2 and NiWO 4 were also detected for W-Ti and W-Ni films, respectively. WO x was present as an inner protective compact layer covered by the porous WO 3 oxide. The best oxidation resistance was found for W-Ti and W-N-Ni coatings which also presented the highest activation energies (E a = 234 and 218 kJ/mol, respectively, as opposed to E a ∼ 188 kJ/mol for the other coatings). These lower oxidation weight gains were attributed to the greater difficulty of the inward diffusion of oxygen ions for W-Ti films, owing to the formation of fine particles of TiO 2 , and the formation of the external, more protective layer of NiWO 4 for W-N-Ni coatings

Photocatalytic TiO2 and Doped TiO2 Coatings to Improve the Hygiene of Surfaces Used in Food and Beverage Processing—A Study of the Physical and Chemical Resistance of the Coatings

Directory of Open Access Journals (Sweden)

Parnia Navabpour

2014-07-01

Full Text Available TiO2 coatings deposited using reactive magnetron sputtering and spray coating methods, as well as Ag- and Mo-doped TiO2 coatings were investigated as self-cleaning surfaces for beverage processing. The mechanical resistance and retention of the photocatalytic properties of the coatings were investigated over a three-month period in three separate breweries. TiO2 coatings deposited using reactive magnetron sputtering showed better mechanical durability than the spray coated surfaces, whilst the spray-deposited coating showed enhanced retention of photocatalytic properties. The presence of Ag and Mo dopants improved the photocatalytic properties of TiO2 as well as the retention of these properties. The spray-coated TiO2 was the only coating which showed light-induced hydrophilicity, which was retained in the coatings surviving the process conditions.

Microstructure and optical properties of Ba0.65Sr0.35TiO3 thin films prepared by RF magnetron sputtering

International Nuclear Information System (INIS)

Zhang Tianjin; Li Songzhan; Zhang Baishun; Pan Ruikun; Jiang Juan; Huang Weihua

2005-01-01

Ba 0.65 Sr 0.35 TiO 3 thin films have been prepared by RF magnetron sputtering. The crystallization and microstructure of the films were characterized by X-ray diffraction (XRD), scan electronic microstructure (SEM) and atom force microstructure (AFM). As-deposited thin films were found to be amorphous. The more intense characteristic diffraction peaks and improved crystallization can be observed in (Ba,Sr)TiO 3 (BST) thin films deposited at high temperatures and annealed at higher than 650degC. Optical constants were determined from transmittance spectra by using the envelope method. The refractive index increased from 1.778 to 1.961 as the substrate temperature increased from 560 to 650degC. Both the refractive index and extinction coefficient increased with annealing temperature. The refractive index and extinction coefficient increased when the oxygen-to-argon ratio increased from 1:4 to 1:1. The dispersion of relation of the extinction coefficient vs wavelength was also investigated. The optical band gap of BST thin films was found to be about 3.56 eV, which decreased apparently with increasing annealing temperature. (author)

Structural and tribological properties of CrTiAlN coatings on Mg alloy by closed-field unbalanced magnetron sputtering ion plating

International Nuclear Information System (INIS)

Shi Yongjing; Long Siyuan; Yang Shicai; Pan Fusheng

2008-01-01

In this paper, a series of multi-layer hard coating system of CrTiAlN has been prepared by closed-field unbalanced magnetron sputtering ion plating (CFUBMSIP) technique in a gas mixture of Ar + N 2 . The coatings were deposited onto AZ31 Mg alloy substrates. During deposition step, technological temperature and metallic atom concentration of coatings were controlled by adjusting the currents of different metal magnetron targets. The nitrogen level was varied by using the feedback control of plasma optical emission monitor (OEM). The structural, mechanical and tribological properties of coatings were characterized by means of X-ray photoelectron spectrometry, high-resolution transmission electron microscope, field emission scanning electron microscope (FESEM), micro-hardness tester, and scratch and ball-on-disc tester. The experimental results show that the N atomic concentration increases and the oxide on the top of coatings decreases; furthermore the modulation period and the friction coefficient decrease with the N 2 level increasing. The outstanding mechanical property can be acquired at medium N 2 level, and the CrTiAlN coatings on AZ31 Mg alloy substrates outperform the uncoated M42 high speed steel (HSS) and the uncoated 316 stainless steel (SS)

Knowledge Management in Scientific and Technical Support Organizations for Regulatory Bodies: SEC NRS Experience

International Nuclear Information System (INIS)

Saulskaya, N.

2016-01-01

Full text: Nuclear industry, similar to other high-tech industries, is based on knowledge and to a great extent depends on personnel qualification, their skills and abilities. Knowledge management processes were recognized of the utmost importance for the IAEA. The IAEA GA adopted a number of resolutions on nuclear knowledge. In this context, knowledge management is considered as an integrated, systematic approach to the process of assessment, obtaining, development, distribution, use, transfer and maintenance of knowledge related to achievement of strategic targets of organization development. KM makes it possible to learn lessons from its own experience. The report presents a long-term experience of SEC NRS in knowledge management and capacity building, which is critically important for SEC NRS as scientific and technical support organization for Rostechnadzor. KM in SEC NRS is performed through the HRM, primarily through HRD, assessment, motivation of the labor activity, and regulation of social-psychological processes. The practice of implementation of NKM through the functions of human resources management is of particular interest for embarking countries. The best practices will be reflected in the IAEA Safety Report “Knowledge Management for Regulatory Bodies and TSO”, which is currently being developed by a team of the IAEA experts. (author

Preparation, properties, and application characteristics of metastable layers of the Ti-Si-C-N system

International Nuclear Information System (INIS)

Fella, R.

1992-10-01

In the Ti-Si-C and Ti-Si-C-N systems, metastable layers were precipitated by means of non-reactive magnetron sputtering of hot-pressed two-phase TiC/SiC and TiN/SiC targets with 20 mole% and 50 mole% SiC. The preparation parameters were varied as follows: ion bombardment during precipitation (bias sputtering), substrate temperature, and annealing times when annealing amorphous 50%:50% TiC/SiC and 50%:50% TiN/SiC layers. Sputtering of targets containing 20% SiC was found to result in monophase fcc layers (NaCl structure). This was documented on the basis of X-ray and electron diffraction patterns. Direct precipitation of targets with 50 mole% SiC resulted in amorphous layers. Increasing the ion bombardment during accretion, raising the substrate temperature, and annealing amorphous 50%:50% TiC/SiC and 50%:50% TiN/SiC (layers precipitated directly) resulted in the crystallization of TiC and TiN nanocrystallites, respectively, imbedded in an amorphous SiC matrix. These crystallites were detected both by X-ray and by electron diffractions and by XPS studies. The XPS measurements of crystalline TiC and amorphous SiC reference layers demonstrated the existence of new kinds of carbon interface phases ('pseudocarbide layers') around TiC and amorphous SiC regions, respectively, which have a positive impact on the mechanical properties of the layers. The hardness of the layers can be correlated with the degrees of crystallization and texture. Adhesion and toughness are worse in SiC-bearing layers than PVD TiC and TiN layers, respectively. The application characteristics of the layers were determined by model wear tests relative to 100Cr6 by means of a pin/disk tribometer. N-bearing layers were found to have clearly higher friction coefficients and greater wear than layers without N. (orig.)

Transparent front contact optimization in dye sensitized solar cells: use of cadmium stannate and titanium oxide by sputtering

Energy Technology Data Exchange (ETDEWEB)

Braga, A., E-mail: antonio.braga@iit.it [CNR-IDASC SENSOR Lab and Department of Chemistry and Physics, Brescia University, Via Valotti 9, 25131 Brescia (Italy); Baratto, C. [CNR-IDASC SENSOR Lab and Department of Chemistry and Physics, Brescia University, Via Valotti 9, 25131 Brescia (Italy); Bontempi, E. [INSTM and Chemistry for Technologies Laboratory, University of Brescia, Via Branze 28, 25133 Brescia (Italy); Colombi, P. [Centro Coating C.S.M.T. Gestione S.c.a.r.l., Via Branze, 45 25123 Brescia (Italy); Sberveglieri, G. [CNR-IDASC SENSOR Lab and Department of Chemistry and Physics, Brescia University, Via Valotti 9, 25131 Brescia (Italy)

2014-03-31

A reliable transparent front contact of cadmium stannate (CTO) and titanium oxide (TiO{sub 2}) entirely deposited by magnetron sputtering has been studied and applied to build standard dye-sensitized solar cell. CTO gives very high average optical transmittance (T{sub avg} ≥ 90%) along with competitive sheet resistance (R{sub sheet} ≤ 15 Ω/sq), while a very thin layer of TiO{sub 2} (thickness < 5 nm) acts as buffer layer to prevent charge recombination. The matched materials allow achievement of good performances of the cells, in terms of short circuit current and power conversion efficiency. UV-visible spectrophotometry, glancing incident X-rays diffraction and X-rays reflectivity techniques were used to characterize thin films before cell realization; sealed solar cells were tested under simulated solar irradiance at 1 Sun to determine functional properties. - Highlights: • Double layer cadmium stannate–TiO{sub 2} transparent front contact by sputtering. • Very thin TiO{sub 2} buffer layer for charge recombination prevention. • Application of novel transparent contact in standard dye sensitized solar cells.

Transparent front contact optimization in dye sensitized solar cells: use of cadmium stannate and titanium oxide by sputtering

International Nuclear Information System (INIS)

Braga, A.; Baratto, C.; Bontempi, E.; Colombi, P.; Sberveglieri, G.

2014-01-01

A reliable transparent front contact of cadmium stannate (CTO) and titanium oxide (TiO 2 ) entirely deposited by magnetron sputtering has been studied and applied to build standard dye-sensitized solar cell. CTO gives very high average optical transmittance (T avg ≥ 90%) along with competitive sheet resistance (R sheet ≤ 15 Ω/sq), while a very thin layer of TiO 2 (thickness < 5 nm) acts as buffer layer to prevent charge recombination. The matched materials allow achievement of good performances of the cells, in terms of short circuit current and power conversion efficiency. UV-visible spectrophotometry, glancing incident X-rays diffraction and X-rays reflectivity techniques were used to characterize thin films before cell realization; sealed solar cells were tested under simulated solar irradiance at 1 Sun to determine functional properties. - Highlights: • Double layer cadmium stannate–TiO 2 transparent front contact by sputtering. • Very thin TiO 2 buffer layer for charge recombination prevention. • Application of novel transparent contact in standard dye sensitized solar cells

Structure adhesion and corrosion resistance study of tungsten bisulfide doped with titanium deposited by DC magnetron co-sputtering

Energy Technology Data Exchange (ETDEWEB)

De La Roche, J. [Laboratorio de Física del Plasma, Universidad Nacional de Colombia Sede Manizales, Km. 9 vía al aeropuerto, Campus La Nubia, Manizales (Colombia); González, J.M. [Laboratorio de Recubrimientos Duros y Aplicaciones Industriales – RDAI, Universidad del Valle, Calle 13 N° 100-00 Ciudadela Meléndez, Cali (Colombia); Restrepo-Parra, E., E-mail: erestrepop@unal.edu.co [Laboratorio de Física del Plasma, Universidad Nacional de Colombia Sede Manizales, Km. 9 vía al aeropuerto, Campus La Nubia, Manizales (Colombia); Sequeda, F. [Laboratorio de Recubrimientos Duros y Aplicaciones Industriales – RDAI, Universidad del Valle, Calle 13 N° 100-00 Ciudadela Meléndez, Cali (Colombia); Alleh, V.; Scharf, T.W. [The University of North Texas, Department of Materials Science and Engineering, Denton, TX 76203 (United States)

2014-11-30

Highlights: • Ti-doped WS{sub 2} films were grown via the magnetron co-sputtering technique. • At a high Ti percentage, the crystalline structure of WS{sub 2} coatings tends to be amorphous. • As the Ti percentage increases in WS{sub 2} coatings, nanocomposites tend to form. • Ti-doped WS{sub 2} films have elastic behavior compared with the plastic response of pure WS{sub 2} films. • A high Ti percentage increases the corrosion resistance of WS{sub 2} films. - Abstract: Titanium-doped tungsten bisulfide thin films (WS{sub 2}-Ti) were grown using a DC magnetron co-sputtering technique on AISI 304 stainless steel and silicon substrates. The films were produced by varying the Ti cathode power from 0 to 25 W. Using energy dispersive spectroscopy (EDS), the concentration of Ti in the WS{sub 2} was determined, and a maximum of 10% was obtained for the sample grown at 25 W. Moreover, the S/W ratio was calculated and determined to increase as a function of the Ti cathode power. According to transmission electron microscopy (TEM) results, at high titanium concentrations (greater than 6%), nanocomposite formation was observed, with nanocrystals of Ti embedded in an amorphous matrix of WS{sub 2}. Using the scratch test, the coatings’ adhesion was analyzed, and it was observed that as the Ti percentage was increased, the critical load (Lc) also increased. Furthermore, the failure type changed from plastic to elastic. Finally, the corrosion resistance was evaluated using the electrochemical impedance spectroscopy (EIS) technique, and it was observed that at high Ti concentrations, the corrosion resistance was improved, as Ti facilitates coating densification and generates a protective layer.

Reactive Ni/Ti nanolaminates

International Nuclear Information System (INIS)

Adams, D. P.; Bai, M. M.; Rodriguez, M. A.; McDonald, J. P.; Jones, E. Jr.; Brewer, L.; Moore, J. J.

2009-01-01

Nickel/titanium nanolaminates fabricated by sputter deposition exhibited rapid, high-temperature synthesis. When heated locally, self-sustained reactions were produced in freestanding Ni/Ti multilayer foils characterized by average propagation speeds between ∼0.1 and 1.4 m/s. The speed of a propagating reaction front was affected by total foil thickness and bilayer thickness (layer periodicity). In contrast to previous work with compacted Ni-Ti powders, no preheating of Ni/Ti foils was required to maintain self-propagating reactions. High-temperature synthesis was also stimulated by rapid global heating demonstrating low ignition temperatures (T ig )∼300-400 deg. C for nanolaminates. Ignition temperature was influenced by bilayer thickness with more coarse laminate designs exhibiting increased T ig . Foils reacted in a vacuum apparatus developed either as single-phase B2 cubic NiTi (austenite) or as a mixed-phase structure that was composed of monoclinic B19 ' NiTi (martensite), hexagonal NiTi 2 , and B2 NiTi. Single-phase, cubic B2 NiTi generally formed when the initial bilayer thickness was made small.

Ion Beam Analysis, structure and corrosion studies of nc-TiN/a-Si{sub 3}N{sub 4} nanocomposite coatings deposited by sputtering on AISI 316L

Energy Technology Data Exchange (ETDEWEB)

García, J. [Departamento de Ingeniería de Proyectos, CUCEI, Universidad de Guadalajara, J. Guadalupe Zuno 48, Los Belenes, Zapopan, Jal. 45101 (Mexico); Canto, C.E. [Instituto de Física, UNAM, Avenida de la Investigación S/N, Coyoacán, México, D.F. 04510 (Mexico); Flores, M. [Departamento de Ingeniería de Proyectos, CUCEI, Universidad de Guadalajara, J. Guadalupe Zuno 48, Los Belenes, Zapopan, Jal. 45101 (Mexico); Andrade, E., E-mail: andrade@fisica.unam.mx [Instituto de Física, UNAM, Avenida de la Investigación S/N, Coyoacán, México, D.F. 04510 (Mexico); Rodríguez, E.; Jiménez, O. [Departamento de Ingeniería de Proyectos, CUCEI, Universidad de Guadalajara, J. Guadalupe Zuno 48, Los Belenes, Zapopan, Jal. 45101 (Mexico); Solis, C.; Lucio, O.G. de [Instituto de Física, UNAM, Avenida de la Investigación S/N, Coyoacán, México, D.F. 04510 (Mexico); Rocha, M.F. [ESIME-Z, Instituto Politécnico Nacional, ALM Zacatenco, México, D.F. 07738 (Mexico)

2014-07-15

In this work, nanocomposite coatings of nc-TiN/a-Si{sub 3}N{sub 4}, were deposited on AISI 316L stainless steel substrate by a DC and RF reactive magnetron co-sputtering technique using an Ar–N{sub 2} plasma. The structure of the coatings was characterized by means of XRD (X-ray Diffraction). The substrate and coating corrosion resistance were evaluated by potentiodynamic polarization using a Ringer solution as electrolyte. Corrosion tests were conducted with the purpose to evaluate the potential of this coating to be used on biomedical alloys. IBA (Ion Beam Analysis) techniques were applied to measure the elemental composition profiles of the films and, XPS (X-ray Photoelectron Spectroscopy) were used as a complementary technique to obtain information about the compounds present in the films. The nanocomposite coatings of nc-TiN/a-Si{sub 3}N{sub 4} show crystalline (TiN) and amorphous (Si{sub 3}N{sub 4}) phases which confer a better protection against the corrosion effects compared with that of the AISI 316L.

Nitrogen implantation of Ti and Ti+Al films deposited on tool steel

International Nuclear Information System (INIS)

Huang, C.-T.; Duh, J.-G.

1995-01-01

Titanium and aluminum thin films were deposited onto A2 steel by rf magnetron sputtering with various Al contents. The coated assembly was then implanted with nitrogen ions at 92 kV and 1 mA for 4.5 h. The thickness of the implanted Ti and Ti+Al films deposited for 1 h was around 0.4-0.5 μm. With the aid of X-ray diffraction by the grazing-incidence technique, secondary ion mass spectrum (SIMS) and X-ray photoelectron spectroscopy (XPS), the titanium oxide and titanium nitride were identified on the top and inner surface in the implanted Ti film. For Ti+Al films after nitrogen implantation, Ti 3 O 5 was formed on the top surface beneath which is a (Ti, Al) N solid solution. There was Ti 2 N compound formed in the implanted Ti film, while only a minor amount of Ti 2 N phase was observed in the inner region in the implanted Ti+Al film. The nitrogen distribution was flattened and spread in the implanted Ti film, while a concentration gradient was observed in the Ti+Al film after implantation. The measured surface hardness of implanted Ti film was higher than those of Ti+Al films and the hardness of implanted Ti+39%Al film was enhanced as compared to the Ti+50%Al film. (Author)

Mechanical Properties of TiTaHfNbZr High-Entropy Alloy Coatings Deposited on NiTi Shape Memory Alloy Substrates

Science.gov (United States)

Motallebzadeh, A.; Yagci, M. B.; Bedir, E.; Aksoy, C. B.; Canadinc, D.

2018-04-01

TiTaHfNbZr high-entropy alloy (HEA) thin films with thicknesses of about 750 and 1500 nm were deposited on NiTi substrates by RF magnetron sputtering using TiTaHfNbZr equimolar targets. The thorough experimental analysis on microstructure and mechanical properties of deposited films revealed that the TiTaHfNbZr films exhibited amorphous and cauliflower-like structure, where grain size and surface roughness increased concomitant with film thickness. More importantly, the current findings demonstrate that the TiTaHfNbZr HEA films with mechanical properties of the same order as those of the NiTi substrate constitute promising biomedical coatings effective in preventing Ni release.

Mechanical Properties of TiTaHfNbZr High-Entropy Alloy Coatings Deposited on NiTi Shape Memory Alloy Substrates

Science.gov (United States)

Motallebzadeh, A.; Yagci, M. B.; Bedir, E.; Aksoy, C. B.; Canadinc, D.

2018-06-01

TiTaHfNbZr high-entropy alloy (HEA) thin films with thicknesses of about 750 and 1500 nm were deposited on NiTi substrates by RF magnetron sputtering using TiTaHfNbZr equimolar targets. The thorough experimental analysis on microstructure and mechanical properties of deposited films revealed that the TiTaHfNbZr films exhibited amorphous and cauliflower-like structure, where grain size and surface roughness increased concomitant with film thickness. More importantly, the current findings demonstrate that the TiTaHfNbZr HEA films with mechanical properties of the same order as those of the NiTi substrate constitute promising biomedical coatings effective in preventing Ni release.

Characteristics of Ti films for transition-edge sensor microcalorimeters

CERN Document Server

Ukibe, M; Ohkubo, M; Pressler, H; Kobayashi, N

1999-01-01

We are developing X-ray microcalorimeters using superconducting transition-edge sensors (TESs), which can be operated at relatively high base temperatures of a sup 3 He cryostat. For this purpose, we have selected Ti films to be used as TESs. The Ti films were deposited on different substrates by RF-sputtering. It was found that the superconducting properties of the Ti films depended on Ar pressure, film thickness, and substrate surface roughness.

Investigation of the Optoelectronic Properties of Ti-doped Indium Tin Oxide Thin Film.

Science.gov (United States)

Pu, Nen-Wen; Liu, Wei-Sheng; Cheng, Huai-Ming; Hu, Hung-Chun; Hsieh, Wei-Ting; Yu, Hau-Wei; Liang, Shih-Chang

2015-09-21

: In this study, direct-current magnetron sputtering was used to fabricate Ti-doped indium tin oxide (ITO) thin films. The sputtering power during the 350-nm-thick thin-film production process was fixed at 100 W with substrate temperatures increasing from room temperature to 500 °C. The Ti-doped ITO thin films exhibited superior thin-film resistivity (1.5 × 10 - ⁴ Ω/cm), carrier concentration (4.1 × 10 21 cm - ³), carrier mobility (10 cm²/Vs), and mean visible-light transmittance (90%) at wavelengths of 400-800 nm at a deposition temperature of 400 °C. The superior carrier concentration of the Ti-doped ITO alloys (>10 21 cm - ³) with a high figure of merit (81.1 × 10 - ³ Ω - ¹) demonstrate the pronounced contribution of Ti doping, indicating their high suitability for application in optoelectronic devices.

The microstructure investigation of GeTi thin film used for non-volatile memory

International Nuclear Information System (INIS)

Shen Jie; Liu Bo; Song Zhitang; Xu Cheng; Liang Shuang; Feng Songlin; Chen Bomy

2008-01-01

GeTi thin film has been found to have the reversible resistance switching property in our previous work. In this paper, the microstructure of this material with a given composition was investigated. The film was synthesized by magnetron sputtering and treated by the rapid temperature process. The results indicate a coexist status of amorphous and polycrystalline states in the as-deposited GeTi film, and the grains in the film are extremely fine. Furthermore, not until the film annealed at 600 deg. C, can the polycrystalline state be detected by X-ray diffraction. Based on the morphological analysis, the sputtered GeTi has the column growth tendency, and the column structure vanishes with the temperature increasing. The microstructure and thermal property analysis indicate that GeTi does not undergo evident phase change process during the annealing process, which makes the switching mechanism of GeTi different from that of chalcogenide memory material, the most widely used phase change memory material

CFD for Nuclear Reactor Safety Applications (CFD4NRS-4) - Workshop Proceedings

International Nuclear Information System (INIS)

2014-01-01

Following the CFD4NRS workshops held in Garching, Germany (Sept. 2006), Grenoble, France (Sep. 2008) and Washington D.C., USA (Sept. 2010), this Workshop is intended to extend the forum created for numerical analysts and experimentalists to exchange information in the application of CFD and CMFD to NRS issues and in guiding nuclear reactor design thinking. The workshop includes single-phase and multi-phase CFD applications, and offers the opportunity to present new experimental data for CFD validation. More emphasis has been given to the experiments, especially on two-phase flow, for advanced CMFD modelling for which sophisticated measurement techniques are required. Understanding of the physics has been depen before starting numerical analysis. Single-phase and multi-phase CFD simulations with a focus on validation were performed in areas such as: single-phase heat transfer, boiling flows, free-surface flows, direct contact condensation and turbulent mixing. These relate to NRS-relevant issues, such as pressurised thermal shock, critical heat flux, pool heat exchangers, boron dilution, hydrogen distribution in containments, thermal striping, etc. The use of systematic error quantification and the application of BPGs were strongly encouraged. Experiments providing data suitable for CFD or CMFD validation were also presented. These included local measurements using multi-sensor probes, laser-based techniques (LDV, PIV or LIF), hot-film/wire anemometry, imaging, or other advanced measuring techniques. There were over 150 registered participants at the CFD4NRS-4 workshop. The programme consisted of 48 technical papers. Of these, 44 were presented orally and 4 as posters. An additional 8 posters related to the OECD/NEA-KAERI sponsored CFD benchmark exercise on turbulent mixing in a rod bundle with spacers (MATiS-H) were presented and a special session was allocated for 6 video presentations. In addition, five keynote lectures were given by distinguished experts. The

Nb and Ta Co-Doped TiO2 Transparent Conductive Thin Films by Magnetron Sputtering: Fabrication, Structure, and Characteristics

Science.gov (United States)

Liu, Yang; Peng, Qian; Qiao, Yadong; Yang, Guang

2018-06-01

Nb and Ta co-doped anatase titanium dioxide (NTTO) nanocrystalline thin films were deposited on quartz and Si (100) substrates by RF magnetron sputtering. The influence of RF power on the growth, structure, morphology, and properties of the samples are discussed in detail. X-ray diffraction measurements show that the films are polycrystalline with anatase tetragonal structure, which is further confirmed by Raman spectroscopy analysis. Meanwhile, Raman spectroscopy results indicate that the peak width of E g(1) mode, which is directly correlated to the carrier density, changes obviously with RF power. It is found that the substitution of Nb5+ and Ta5+ at Ti site is significantly improved with the increase of RF power from 150 W to 210 W. For the sample deposited at 210 W, the optical transmittance is above 82% in the visible range and the electrical resistivity is as low as 1.3 × 10-3 Ω cm with carrier density of 1.1 × 1021 cm-3 and Hall mobility of 4.5 cm2 V-1 s-1. The optical and electrical properties of NTTO thin films can be compared to those of Nb or Ta doped anatase TiO2. However, co-doping with Nb and Ta gives a possible platform to complement the limitations of each individual dopant.

Thermal conductivities of thin, sputtered optical films

International Nuclear Information System (INIS)

Henager, C.H. Jr.; Pawlewicz, W.T.

1991-05-01

The normal component of the thin film thermal conductivity has been measured for the first time for several advanced sputtered optical materials. Included are data for single layers of boron nitride (BN), aluminum nitride (AIN), silicon aluminum nitride (Si-Al-N), silicon aluminum oxynitride (Si-Al-O-N), silicon carbide (SiC), and for dielectric-enhanced metal reflectors of the form Al(SiO 2 /Si 3 N 4 ) n and Al(Al 2 O 3 /AIN) n . Sputtered films of more conventional materials like SiO 2 , Al 2 O 3 , Ta 2 O 5 , Ti, and Si have also been measured. The data show that thin film thermal conductivities are typically 10 to 100 times lower than conductivities for the same materials in bulk form. Structural disorder in the amorphous or very fine-grained films appears to account for most of the conductivity difference. Conclusive evidence for a film/substrate interface contribution is presented

Structures and magnetic behaviours of TiO2–Mn–TiO2 multilayers

International Nuclear Information System (INIS)

Fa-Min, Liu; Peng, Ding; Jian-Qi, Li

2010-01-01

The TiO 2 -Mn-TiO 2 multilayers are successfully grown on glass and silicon substrates by alternately using radio frequency reactive magnetron sputtering and direct current magnetron sputtering. The structures and the magnetic behaviours of these films are characterised with x-ray diffraction, transmission electron microscope (TEM), vibrating sample magnetometer, and superconducting quantum interference device (SQUID). It is shown that the multi-film consists of a mixture of anatase and rutile TiO 2 with an embedded Mn nano-film. It is found that there are two turning points from ferromagnetic phase to antiferromagnetic phase. One is at 42 K attributed to interface coupling between ferromagnetic Mn 3 O 4 and antiferromagnetic Mn 2 O 3 , and the other is at 97 K owing to the interface coupling between ferromagnetic Mn and antiferromagnetic MnO. The samples are shown to have ferromagnetic behaviours at room temperature from hysteresis in the M-H loops, and their ferromagnetism is found to vary with the thickness of Mn nano-film. Moreover, the Mn nano-film has a critical thickness of about 18.5 nm, which makes the coercivity of the multi-film reach a maximum of about 3.965×10 −2 T. (cross-disciplinary physics and related areas of science and technology)

Thin NiTi Films Deposited on Graphene Substrates

Science.gov (United States)

Hahn, S.; Schulze, A.; Böhme, M.; Hahn, T.; Wagner, M. F.-X.

2017-03-01

We present experimental results on the deposition of Nickel Titanium (NiTi) films on graphene substrates using a PVD magnetron sputter process. Characterization of the 2-4 micron thick NiTi films by electron microscopy, electron backscatter diffraction, and transmission electron microscopy shows that grain size and orientation of the thin NiTi films strongly depend on the type of combination of graphene and copper layers below. Our experimental findings are supported by density functional theory calculations: a theoretical estimation of the binding energies of different NiTi-graphene interfaces is in line with the experimentally determined microstructural features of the functional NiTi top layer.

Pb(Zr,TiO3 (PZT Thin Film Sensors for Fully-Integrated, Passive Telemetric Transponders

Directory of Open Access Journals (Sweden)

Richard X. FU

2011-04-01

Full Text Available The great potential of taking advantages of PZT in a single chip to achieve inexpensive, fully-integrated, passive telemetric transponders has been shown in this paper. The processes for the sputter deposition of Pb(Zr,TiO3 (PZT thin films from two different composite targets on both Si and c-plane sapphire substrates have been demonstrated. PZT thin films have been deposited by sputter technique. PZT films were deposited onto substrates (Si [(100 Cz wafer] and c-plane sapphire (0001//Ti//Pt followed by sputter-deposited Pt top electrodes. X-ray diffraction results showed that both sputtered PZT films were textured along the [110] direction. The degree of preference for the [110] direction was greater on sapphire substrate where the intensity of that peak is seen to be larger compared to the intensity one Si substrate. TEM data revealed that both sputtered PZT films were polycrystalline in nature. Selected area diffraction (SAD pattern showed that the degree of disorientation between the crystallites was smaller on sapphire substrate compared to on Si substrate, which confirmed the results from the XRD. The remnant polarization Pr on sapphire substrate was larger than on Si’s. The leakage current for the 11 % Pb target sputtered film was much less than 22 % Pb target sputtered film. The breakdown voltage on sapphire substrate was the best. However, for the 11 % Pb target sputtered film’s breakdown voltage was much higher than 22 % Pb target sputtered film.

Low Fatigue in Epitaxial Pb(Zr0.2Ti0.8)O3 on Si Substrates with LaNiO3 Electrodes by RF Sputtering

Science.gov (United States)

Wang, Chun; Kryder, Mark H.

2009-09-01

Epitaxial PZT (001) thin films with a LaNiO3 bottom electrode were deposited by radio-frequency (RF) sputtering onto Si(001) single-crystal substrates with SrTiO3/TiN buffer layers. Pb(Zr0.2Ti0.8)O3 (PZT) samples were shown to consist of a single perovskite phase and to have an (001) orientation. The orientation relationship was determined to be PZT(001)[110]∥LaNiO3(001)[110]∥SrTiO3 (001)[110]∥TiN(001)[110]∥Si(001)[110]. Atomic force microscope (AFM) measurements showed the PZT films to have smooth surfaces with a roughness of 1.15 nm. The microstructure of the multilayer was studied using transmission electron microscopy (TEM). Electrical measurements were conducted using both Pt and LaNiO3 as top electrodes. The measured remanent polarization P r and coercive field E c of the PZT thin film with Pt top electrodes were 23 μC/cm2 and 75 kV/cm, and were 25 μC/cm2 and 60 kV/cm for the PZT film with LaNiO3 top electrodes. No obvious fatigue after 1010 switching cycles indicated good electrical endurance of the PZT films using LaNiO3 electrodes, compared with the PZT film with Pt top electrodes showing a significant polarization loss after 108 cycles. These PZT films with LaNiO3 electrodes could be potential recording media for probe-based high-density data storage.

Ion-induced sputtering

International Nuclear Information System (INIS)

Yamamura, Yasumichi; Shimizu, Ryuichi; Shimizu, Hazime; Ito, Noriaki.

1983-01-01

The research on ion-induced sputtering has been continued for a long time, since a hundred or more years ago. However, it was only in 1969 by Sigmund that the sputtering phenomena were theoretically arranged into the present form. The reason why the importance of sputtering phenomena have been given a new look recently is the application over wide range. This paper is a review centering around the mechanism of causing sputtering and its characteristics. Sputtering is such a phenomenon that the atoms in the vicinity of a solid surface are emitted into vacuum by receiving a part of ion energy, or in other words, it is a kind of irradiation damage in the vicinity of a solid surface. In this meaning, it can be considered that the sputtering based on the ions located on the clean surface of a single element metal is simple, and has already been basically understood. On the contrary, the phenomena can not be considered to be fully understood in the case of alloys and compounds, because these surface conditions under irradiation are not always clear due to segregation and others. In the paper, the physical of sputtering, single element sputtering, the sputtering in alloys and compounds, and the behaviour of emitted particles are explained. Finally, some recent topics of the sputtering measurement by laser resonant excitation, the sputtering by electron excitation, chemical sputtering, and the sputtering in nuclear fusion reactors are described. (Wakatsuki, Y.)

Effect of ZnO decoration on the photovoltaic performance of TiO{sub 2} based dye sensitized solar cells

Energy Technology Data Exchange (ETDEWEB)

Yang, Long; Zhai, Bao-gai [School of Mathematics and Physics, Changzhou University, Jiangsu 213164 (China); Ma, Qing-lan [School of Electronics and Information, Nantong University, Jiangsu 226019 (China); Huang, Yuan Ming, E-mail: dongshanisland@126.com [School of Electronics and Information, Nantong University, Jiangsu 226019 (China)

2014-08-25

Highlights: • Various ZnO morphologies coated TiO{sub 2} photoanodes are formed and applied to DSSCs. • The effect of photoanode morphology on performance of DSSCs was studied. • ZnO NRs@TiO{sub 2} electrode provides more dye absorption and fast transfer pathway. • The η of DSSC with ZnO NRs@TiO{sub 2} is increased over fourfold than other DSSCs. - Abstract: ZnO nanoparticles and one-dimensional vertically aligned ZnO nanorods were grown on the TiO{sub 2} layers in the photoanodes via the hydrothermal method at 60 and 90 °C, respectively. The effect of ZnO decoration on the photovoltaic performance of TiO{sub 2} based dye sensitized solar cells (DSSCs) was investigated. The morphologies, crystalline structures and optical properties of the synthesized ZnO nanoparticles and ZnO nanorods were characterized by field-emission scanning electron microscope, X-ray diffractometer and photoluminescence spectroscopy, respectively. The photocurrent–voltage curves of the fabricated DSSCs showed that the ZnO nanorods decorated DSSCs exhibited better photovoltaic performance than the ZnO nanoparticles decorated DSSCs. The improved performance of the ZnO nanorods decorated DSSCs can be ascribed to the fact that the vertically aligned ZnO nanorods provide high specific surface area for dye adsorption and the efficient pathway for electron transportation.

Morphology controlled ultrafine BaTiO3 based PVDF-HFP ...

Indian Academy of Sciences (India)

21

... for real applications. Kew Words: Polygonal, Barium Titanate, Hydrothermal, Dielectric and Sensor. 1. 2 ... structure and can be tuned further by substituting various dopants (Sr, Ca and Zr). .... Modified BaTiO3 induces less displacement of Ti and O ions along c- axis and .... sputter coated on both sides with gold. The films ...

Antibacterial activity of single crystalline silver-doped anatase TiO{sub 2} nanowire arrays

Energy Technology Data Exchange (ETDEWEB)

Zhang, Xiangyu, E-mail: zhangxiangyu@tyut.edu.cn; Li, Meng; He, Xiaojing; Hang, Ruiqiang; Huang, Xiaobo; Wang, Yueyue; Yao, Xiaohong; Tang, Bin, E-mail: tangbin@tyut.edu.cn

2016-05-30

Graphical abstract: The silver-doped TiO{sub 2} nanowire arrays on titanium foil substrate were synthesized via a two-step process. It includes: deposition of AgTi films on titanium foil by magnetron sputtering; preparation of AgNW arrays on AgTi films via alkali (NaOH) hydrothermal treatment and ion-exchange with HCl, followed by calcinations. - Highlights: • Ag-doped TiO{sub 2} nanowire arrays have been prepared by a duplex-treatment. • The duplex-treatment consisted of magnetron sputtering and hydrothermal growth. • Ag-doped nanowire arrays show excellent antibacterial activity against E. coli. - Abstract: Well-ordered, one-dimensional silver-doped anatase TiO{sub 2} nanowire (AgNW) arrays have been prepared through a hydrothermal growth process on the sputtering-deposited AgTi layers. Electron microscope analyses reveal that the as-synthesized AgNW arrays exhibit a single crystalline phase with highly uniform morphologies, diameters ranging from 85 to 95 nm, and lengths of about 11 μm. Silver is found to be doped into TiO{sub 2} nanowire evenly and mainly exists in the zerovalent state. The AgNW arrays show excellent efficient antibacterial activity against Escherichia coli (E. coli), and all of the bacteria can be killed within 1 h. Additionally, the AgNW arrays can still kill E. coli after immersion for 60 days, suggesting the long-term antibacterial property. The technique reported here is environmental friendly for formation of silver-containing nanostructure without using any toxic organic solvents.

Investigation of the Optoelectronic Properties of Ti-doped Indium Tin Oxide Thin Film

Directory of Open Access Journals (Sweden)

Nen-Wen Pu

2015-09-01

Full Text Available : In this study, direct-current magnetron sputtering was used to fabricate Ti-doped indium tin oxide (ITO thin films. The sputtering power during the 350-nm-thick thin-film production process was fixed at 100 W with substrate temperatures increasing from room temperature to 500 °C. The Ti-doped ITO thin films exhibited superior thin-film resistivity (1.5 × 10−4 Ω/cm, carrier concentration (4.1 × 1021 cm−3, carrier mobility (10 cm2/Vs, and mean visible-light transmittance (90% at wavelengths of 400–800 nm at a deposition temperature of 400 °C. The superior carrier concentration of the Ti-doped ITO alloys (>1021 cm−3 with a high figure of merit (81.1 × 10−3 Ω−1 demonstrate the pronounced contribution of Ti doping, indicating their high suitability for application in optoelectronic devices.

Sputtered catalysts

International Nuclear Information System (INIS)

Tyerman, W.J.R.

1978-01-01

A method is described for preparing a supported catalyst by a sputtering process. A material that is catalytic, or which is a component of a catalytic system, is sputtered on to the surface of refractory oxide particles that are compatible with the sputtered material and the sputtered particles are consolidated into aggregate form. The oxide particles before sputtering should have a diameter in the range 1000A to 50μ and a porosity less than 0.4 ml/g, and may comprise MgO, Al 2 O 3 or SiO 2 or mixtures of these oxides, including hydraulic cement. The particles may possess catalytic activity by themselves or in combination with the catalytic material deposited on them. Sputtering may be effected epitaxially and consolidation may be effected by compaction pelleting, extrusion or spray drying of a slurry. Examples of the use of such catalysts are given. (U.K.)

Intensity of evaporation fields of metals in an electrical field and sputtering of metals at an ionic bombardment

International Nuclear Information System (INIS)

Kajbichev, A.V.; Pastukhov, Eh.A.; Kajbichev, I.A.; Aleshina, S.N.

2001-01-01

The electric field intensity for liquid metal evaporation is calculated. The correlation is established between the evaporating field intensity, ion sputtering and boiling temperatures for a number of metals (W, Nb, Mo, Ti, Co, Ni) with accounting for the fact that above-mentioned parameters characterize the expenditure of energy for removal of one-charge ions. It is shown that the dependence of evaporating field intensity on the number of the metal in the Periodic system is of oscillating nature. The disagreement between evaporating field intensity and Ar + ion sputtering for such metals as Cr, Ag, Cu can be explained by multi-charge type of sputtered particles [ru

Hydrogen insertion in titanium carbide based thin films (nc-TiC{sub x}/a-C:H) - comparison with bulk TiC{sub x}

Energy Technology Data Exchange (ETDEWEB)

Nguyen, Julien; Jaoul, Cédric, E-mail: jaoul@ensil.unilim.fr; Glandut, Nicolas; Lefort, Pierre

2016-08-01

Nanocomposites composed of titanium carbide nanosized grains embedded in an amorphous hydrogenated carbon matrix (nc-TiC{sub x}/a-C:H) are prepared by hybrid Magnetron Sputtering - PECVD process using a titanium metal target and gaseous C{sub 6}H{sub 6}. By controlling the benzene flow rate, thin films with different carbon content are obtained. The structures of nc-TiC{sub x}/a-C:H materials are analyzed by X-ray diffraction, X-ray photoelectron and Raman spectroscopic methods. The electrochemical hydrogen insertion, as studied by cyclic voltammetry, strongly depends on the carbon content in the thin films. The correlation between the hydrogen insertion ability and the structure of materials are discussed. Furthermore, we show that the hydrogen insertion in these thin films reaches values much more significant than in bulk substoichiometric titanium carbide obtained by reactive sintering. - Highlights: • nc-TiC{sub x}/a-C:H thin films are prepared hybrid Magnetron Sputtering - PECVD process. • Different carbon contents are obtained by changing the hydrocarbon flowrate. • Expanded lattice parameter of the TiC{sub x} phase and a-C:H phase are observed. • Electrochemical hydrogen insertion strongly depends on the carbon content. • The maximum insertion is 22 times more important than bulk TiC{sub x}.

Information for forest process models: a review of NRS-FIA vegetation measurements

Science.gov (United States)

Charles D. Canham; William H. McWilliams

2012-01-01

The Forest and Analysis Program of the Northern Research Station (NRS-FIA) has re-designed Phase 3 measurements and intensified the sample intensity following a study to balance costs, utility, and sample size. The sampling scheme consists of estimating canopy-cover percent for six vegetation growth habits on 24-foot-radius subplots in four height classes and as an...

Application of TiN/TiO2 coatings on stainless steel: composition and mechanical reliability

Science.gov (United States)

Nikolova, M. P.; Genov, A.; Valkov, S.; Yankov, E.; Dechev, D.; Ivanov, N.; Bezdushnyi, R.; Petrov, P.

2018-03-01

The paper reports on the effect of the substrate temperature (350 °C, 380 °C and 420 °C) during reactive magnetron sputtering of a TiN film on the phase composition, texture and mechanical properties of TiN/TiO2 coatings on 304L stainless steel substrates. Pure Ti was used as a cathode source of Ti. The texture and unit cell parameters of both TiN and TiO2 phases of the coating are discussed in relation with the tribological properties and adhesion of the coating. The scratch tests performed showed that the nitride deposited at 380 °C, having the highest unit cell parameter and a predominant (111) texture, possessed the lowest friction coefficient (μ), tangential force and brittleness. The anatase-type TiO2 with predominant (101) pole density and increased c unit cell parameter showed the highest stability on the nitride deposited at 420 °C. The results indicated that the friction coefficient, tangential force and critical forces of fracture could be varied by controlling the coating deposition temperature.

Structural analysis of a coating of TiN over a Cu-Ti-Cr alloy: Study of the Cu-Ti interphase

International Nuclear Information System (INIS)

Villegas Vejar, C; Suazo, A; Radtk, H; Carrasco, C

2004-01-01

The crystalline structure of a thin film of TiN deposited by DC planar magnetron sputtering over a ternary copper alloy was studied. A fine film of titanium was deposited between the coating and the substrate for better adherence. The samples were analyzed with a transmission electron microscope to determine the structure of each of the components as well as the network distortion in the Cu-Ti interphase. The results were complemented with previous X-ray diffraction analyses to identify the network parameter for each of the study components and the respective residual tensions. This study shows the agreement between the network distortion and the residual tensions that were measured, and also relates the theory of crystalline coherence with the experimentally calculated break down by electron diffraction in the Cu-Ti interphase (CW)

Fabrication and characterizations of ZnO nanorods/Au nanoparticle composites on the electropolished Ti substrate

Energy Technology Data Exchange (ETDEWEB)

Chen, Hsiang, E-mail: hchen@ncnu.edu.tw [National Chi Nan University, No.1, Daxue Rd., Puli Township, Nantou County 545, Taiwan, ROC (China); Yeh, Yih-Min [WuFeng University, No. 117, Sec 2, Chiankuo Rd, Minhsiung, Chiayi County 62153, Taiwan, ROC (China); Chen, Jian-Zhi [National Chi Nan University, No.1, Daxue Rd., Puli Township, Nantou County 545, Taiwan, ROC (China); Liu, Song-Ming [WuFeng University, No. 117, Sec 2, Chiankuo Rd, Minhsiung, Chiayi County 62153, Taiwan, ROC (China); Huang, Bo Yun; Wu, Zhi-Huei; Tsai, Shaung-Lin; Chang, Hung-Wei; Chu, Yu-Cheng; Liao, Chuan Hao [National Chi Nan University, No.1, Daxue Rd., Puli Township, Nantou County 545, Taiwan, ROC (China)

2013-12-31

Au nanoparticles (NPs) were spread on ZnO nanorods (NRs) on the polished Ti substrate to form Au/ZnO nanocomposites. Multiple material analyses including field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) analyses, Fourier-transform infrared spectrometer (FTIR) and images taken by optical microscope were performed on Au NPs of 2 nm and 20 nm on ZnO NRs. The FESEM and optical images under optical microscope indicate that 20 nm NPs can form more and larger clusters than 2 nm NPs on ZnO nanorod. Furthermore, more Au can be detected by EDS and XRD. We studied the behaviors of Au NPs on ZnO NR applications for future potential biosensing and antiseptic devices. - Highlights: • Nanocomposites of Au nanoparticles were spread on ZnO nanorods on Ti substrate. • Multiple material analyses were performed on 2 nm and 20 nm nanoparticles. • 20 nm nanoparticles formed more and larger clusters. • Optical images show well-distributed nanoparticle ZnO nanorods.

Preparation and study of nanostructured TiAlSiN thin films

Directory of Open Access Journals (Sweden)

Jakab-Farkas L.

2011-12-01

Full Text Available TiAlSiN thin film coatings were deposited by DC reactive magnetron sputtering of TiAlSi target with 40 at.% Ti, 40 at.% Al and 20 at.% Si, performed in N2-Ar gas mixture. The sputtering power used in these experiments was controlled for 400 W. The bias voltage of the substrates was kept at -20 V DC and the temperature at 500 0C. All the samples were prepared with a constant flow rate of Ar and different nitrogen flow rates, which were selected from 1.25 sccm to 4.0 sccm. Nanostructured TiAlSiN coatings were developed on Si(100 and HSS substrates. Microstructure investigation of the coatings was performed by transmission electron microscopy investigation, structure investigation was performed by XRD analysis, and the mechanical properties of the coatings have been tested by ball-on-disk tribological investigation and micro-Vickers hardness measurements. In this paper will be shown that for optimized nitrogen concentration the microstructure of TiAlSiN coating evolve from a competitive columnar growth to a dendritic growth one with very fine nano-lamellae like morphology. The developed nanostructured TiAlSiN coatingshave hardness HV exceeding 40 GPa and show an increased abrasive wear resistance

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.

Ga lithography in sputtered niobium for superconductive micro and nanowires

International Nuclear Information System (INIS)

Henry, M. David; Wolfley, Steve; Monson, Todd; Lewis, Rupert

2014-01-01

This work demonstrates the use of focused ion beam (FIB) implanted Ga as a lithographic mask for plasma etching of Nb films. Using a highly collimated Ga beam of a FIB, Nb is implanted 12 nm deep with a 14 nm thick Ga layer providing etch selectivity better than 15:1 with fluorine based etch chemistry. Implanted square test patterns, both 10 μm by 10 μm and 100 μm by 100 μm, demonstrate that doses above than 7.5 × 10 15  cm −2 at 30 kV provide adequate mask protection for a 205 nm thick, sputtered Nb film. The resolution of this dry lithographic technique is demonstrated by fabrication of nanowires 75 nm wide by 10 μm long connected to 50 μm wide contact pads. The residual resistance ratio of patterned Nb films was 3. The superconducting transition temperature (T c ) = 7.7 K was measured using a magnetic properties measurement system. This nanoscale, dry lithographic technique was extended to sputtered TiN and Ta here and could be used on other fluorine etched superconductors such as NbN, NbSi, and NbTi.

Rutherford backscattering analysis of glass surfaces and TiOsub(x) thin films

Energy Technology Data Exchange (ETDEWEB)

Fischer, H; Hacker, E; Schirmer, G

1981-11-20

The composition of sputter-etched substrate surfaces is critically dependent on the conditions in the sputtering system before etching, on the position of the sample within this system and on the chemical sample cleaning. The stoichiometric values for thin TiOsub(x) films are greater than 2 (up to 2.9). Additional oxygen is physisorbed in the layers. Argon atoms are embedded in the substrate-layer interface region of bias-sputtered films. Gas entrapments can be explained from the formation of the initial film structure in the interface region.

Peculiarities in film growth of ferroelectric complex oxides in ion-plasma sputtering

International Nuclear Information System (INIS)

Mukhortov, V.M.; Golovko, Yu.I.; Mukhortov, Vl.M.; Dudkevich, V.P.

1981-01-01

Experimental investigation into the process of complex oxide film growth (using BaTiO 3 and (Ba,Sr)TiO 3 as an example) during ion-plasma sputtering has been carried out. It is shown that neutral excited atoms are knocked out of a ceramic target during its ion bombardment. Removing from the target they loss energy at the expence of collisions and at some distance hsub(cr) the oxidation reaction (BaO, TiO, TiO 2 , SrO) becomes possible. So the ''construction'' material comes in either in the form of atoms or in the form of molecules of simple oxides depending on a distance between cathode and substrate. Two mechanisms of synthesis and crystallization distinguished with dependences of growth rate, elementary cell parameters and other structure characteristics on precipitation temperature correspond to two precipitation mechanisms. Part of re-evaporation and reduction processes is discussed [ru

Structural and sensing characteristics of Gd2Ti2O7, Er2TiO5 and Lu2Ti2O7 sensing membrane electrolyte–insulator–semiconductor for bio-sensing applications

International Nuclear Information System (INIS)

Pan, Tung-Ming; Liao, Pei-You; Chang, Kung-Yuan; Chi, Lifeng

2013-01-01

Highlights: ► The structural and sensing properties of Gd 2 Ti 2 O 7 , Er 2 TiO 5 and Lu 2 Ti 2 O 7 sensing films grown on Si substrates by reactive co-sputtering. ► The EIS device incorporating a Lu 2 Ti 2 O 7 sensing film exhibited a higher sensitivity, a larger drift rate, a higher hysteresis voltage, and a larger hysteresis gap than other sensing films. ► The impedance effect of EIS sensors has been investigated using C–V method. -- Abstract: This paper describes the structural and sensing characteristics of Gd 2 Ti 2 O 7 , Er 2 TiO 5 , and Lu 2 Ti 2 O 7 sensing membranes deposited on Si substrates through reactive co-sputtering for electrolyte–insulator–semiconductor (EIS) pH sensors. In this work, the structural properties of Gd 2 Ti 2 O 7 , Er 2 TiO 5 , and Lu 2 Ti 2 O 7 membranes were investigated by X-ray diffraction, atomic force microscopy and X-ray photoelectron spectroscopy. The observed structural properties were then correlated with the resulting pH sensing performances. The EIS device incorporating a Lu 2 Ti 2 O 7 sensing film exhibited a higher sensitivity (59.32 mV pH −1 ), a larger drift rate (0.55 mV h −1 ), a higher hysteresis voltage (5 mV), and a larger hysteresis gap (∼70 mV) compared to those of the other sensing films. This result is attributed to the higher surface roughness and the formation of a thicker interfacial layer at the oxide–Si interface. Furthermore, the impedance effect of EIS sensors has been investigated using capacitance–voltage (C–V) method (frequency-dependent C–V curves). From the impedance spectroscopy analysis, we find that the diameter of a semicircle of an EIS sensor becomes smaller due to a gradual decrease in the bulk resistance of the device with degree of pH value

AlTiN layer effect on mechanical properties of Ti-doped diamond-like carbon composite coatings

International Nuclear Information System (INIS)

Pang Xiaolu; Yang Huisheng; Gao Kewei; Wang Yanbin; Volinsky, Alex A.

2011-01-01

Ti/Ti-doped diamond-like carbon (DLC) and Ti/AlTiN/Ti-DLC composite coatings were deposited by magnetron sputtering on W18Cr4V high speed steel substrates. The effect of the AlTiN support layer on the properties of these composite coatings was investigated through microstructure and mechanical properties characterization, including hardness, elastic modulus, coefficient of friction and wear properties measured by scanning electron microscopy, Raman spectroscopy, scratch and ball-on-disk friction tests. Ti and AlTiN interlayers have a columnar structure with 50-80 nm grains. The hardness and elastic modulus of Ti/Ti-DLC and Ti/AlTiN/Ti-DLC coatings is 25.9 ± 0.4, 222.2 ± 6.3 GPa and 19.3 ± 1, 205.6 ± 6.7 GPa, respectively. Adhesion of Ti-DLC, Ti/AlTiN/Ti-DLC and AlTiN/Ti-DLC coatings expressed as the critical lateral force is 26.5 N, 38.2 N, and 47.8 N, respectively. Substrate coefficient of friction without coatings is 0.44, and it is 0.1 for Ti/Ti-DLC and Ti/AlTiN/Ti-DLC coatings. Wear resistance of Ti/AlTiN/Ti-DLC composite coatings is much higher than Ti/Ti-DLC coatings based on the wear track width of 169.8 and 73.2 μm, respectively, for the same experimental conditions.

Vacuum Pumping Performance Comparison of Non-Evaporable Getter Thin Films Deposited Using Argon and Krypton as Sputtering Gases

CERN Document Server

Liu, Xianghong; He, Yun; Li, Yulin

2005-01-01

Owing to the outstanding vacuum performance and the low secondary electron yield, non-evaporable getter (NEG) thin film deposited onto interior walls has gained widespread acceptance and has been incorporated into many accelerator vacuum system designs. The titanium-zirconium-vanadium (T-Zr-V) NEG thin films were deposited onto the interior wall of stainless steel pipes via DC magnetron sputtering method using either argon or krypton gas as sputtering gas. Vacuum pumping evaluation tests were carried out to compare vacuum pumping performances of the Ti-Zr-V NEG thin films deposited using argon or krypton. The results showed much higher initial pumping speed for the Kr-sputtered NEG film than the Ar-sputtered film, though both films have similar activation behavior. The compositions and textures of both thin films were measured to correlate to the pumping performances.

A Low Temperature Synthetic Route to Nanocrystalline TiN

African Journals Online (AJOL)

NICO

This method may be extended to the synthesis of other metal nitrides. ... direct current magnetron sputtering17, and mechanical mill- ... recent years, autoclaved synthesis of TiN nanomaterials from ... 3.2 XPS Characterization of the Samples.

Magnetic and spin-dependent transport properties of reactive sputtered epitaxial Ti 1-xCr xN films

KAUST Repository

Duan, Xiaofei; Mi, Wenbo; Guo, Zaibing; Bai, Haili

2012-01-01

Reactive-sputtered epitaxial Ti 1-xCr xN films are ferromagnetic in the range of 0.17 ≤ x ≤ 0.51 due to the Cr-N-Cr double-exchange interaction below the Curie temperature (T C). The T C first increases, then decreases as x increases, and a maximum of 120 K appears at x = 0.47. All of the films are metallic with a transition near T C. A resistivity minimum ρ min is observed below 60 K in the films with 0.10 ≤ x ≤ 0.51 due to the effects of the weak localization and electron-electron interaction. The negative magnetoresistance (MR) is caused by the double-exchange interaction below T C and the weak localization can also contribute to MR below T min where ρ min appears. The x-dependent electron carrier densities reveal that the ferromagnetism is not from the carrier-mediated mechanism. The anomalous Hall resistivity follows the relation of ρxyA∝ρxx2, which is from the side-jump mechanism. © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Magnetic and spin-dependent transport properties of reactive sputtered epitaxial Ti 1-xCr xN films

KAUST Repository

Duan, Xiaofei

2012-05-01

Reactive-sputtered epitaxial Ti 1-xCr xN films are ferromagnetic in the range of 0.17 ≤ x ≤ 0.51 due to the Cr-N-Cr double-exchange interaction below the Curie temperature (T C). The T C first increases, then decreases as x increases, and a maximum of 120 K appears at x = 0.47. All of the films are metallic with a transition near T C. A resistivity minimum ρ min is observed below 60 K in the films with 0.10 ≤ x ≤ 0.51 due to the effects of the weak localization and electron-electron interaction. The negative magnetoresistance (MR) is caused by the double-exchange interaction below T C and the weak localization can also contribute to MR below T min where ρ min appears. The x-dependent electron carrier densities reveal that the ferromagnetism is not from the carrier-mediated mechanism. The anomalous Hall resistivity follows the relation of ρxyA∝ρxx2, which is from the side-jump mechanism. © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Isotope puzzle in sputtering

International Nuclear Information System (INIS)

Zheng Liping

1998-01-01

Mechanisms affecting multicomponent material sputtering are complex. Isotope sputtering is the simplest in the multicomponent materials sputtering. Although only mass effect plays a dominant role in the isotope sputtering, there is still an isotope puzzle in sputtering by ion bombardment. The major arguments are as follows: (1) At the zero fluence, is the isotope enrichment ejection-angle-independent or ejection-angle-dependent? (2) Is the isotope angular effect the primary or the secondary sputter effect? (3) How to understand the action of momentum asymmetry in collision cascade on the isotope sputtering?

Optimizing Pt/TiO2 templates for textured PZT growth and MEMS devices

Science.gov (United States)

Potrepka, Daniel; Fox, Glenn; Sanchez, Luz; Polcawich, Ronald

2013-03-01

Crystallographic texture of lead zirconate titanate (PZT) thin films strongly influences piezoelectric properties used in MEMS applications. Textured growth can be achieved by relying on crystal growth habit and can also be initiated by the use of a seed-layer heteroepitaxial template. Template choice and the process used to form it determine structural quality, ultimately influencing performance and reliability of MEMS PZT devices such as switches, filters, and actuators. This study focuses on how 111-textured PZT is generated by a combination of crystal habit and templating mechanisms that occur in the PZT/bottom-electrode stack. The sequence begins with 0001-textured Ti deposited on thermally grown SiO2 on a Si wafer. The Ti is converted to 100-textured TiO2 (rutile) through thermal oxidation. Then 111-textured Pt can be grown to act as a template for 111-textured PZT. Ti and Pt are deposited by DC magnetron sputtering. TiO2 and Pt film textures and structure were optimized by variation of sputtering deposition times, temperatures and power levels, and post-deposition anneal conditions. The relationship between Ti, TiO2, and Pt texture and their impact on PZT growth will be presented. Also affiliated with U.S. Army Research Lab, Adelphi, MD 20783, USA

Preparation of hydrogenated-TiO2/Ti double layered thin films by water vapor plasma treatment

International Nuclear Information System (INIS)

Pranevicius, L.L.; Milcius, D.; Tuckute, S.; Gedvilas, K.

2012-01-01

Highlights: ► We investigated reaction of water plasma with nanocrystalline TiO 2 films. ► Simultaneous oxidation and hydrogenation of Ti was observed during plasma treatment. ► Water plasma treatment forms hydrogenated nanocrystalline TiO 2 in the shallow surface. - Abstract: We have investigated the structural and compositional variations in 200–500 nm thick Ti films deposited by magnetron sputter-deposition technique and treated in water vapor plasma at different processing powers. It was found that the upper layer of treated film with the thickness of 110 nm was changed into the black hydrogenated-TiO 2 with around 16 nm sized nanocystals during 10 min for dissipated power 200 W at room temperature. Analysis of the experimental results is used to obtain insights into the effects of water layer adsorbed on hydrophilic oxidized titanium surfaces exposed to plasma radiation.

Preheat effect on titanium plate fabricated by sputter-free selective laser melting in vacuum

Science.gov (United States)

Sato, Yuji; Tsukamoto, Masahiro; Shobu, Takahisa; Yamashita, Yorihiro; Yamagata, Shuto; Nishi, Takaya; Higashino, Ritsuko; Ohkubo, Tomomasa; Nakano, Hitoshi; Abe, Nobuyuki

2018-04-01

The dynamics of titanium (Ti) melted by laser irradiation was investigated in a synchrotron radiation experiment. As an indicator of wettability, the contact angle between a selective laser melting (SLM) baseplate and the molten Ti was measured by synchrotron X-rays at 30 keV during laser irradiation. As the baseplate temperature increased, the contact angle decreased, down to 28° at a baseplate temperature of 500 °C. Based on this result, the influence of wettability of a Ti plate fabricated by SLM in a vacuum was investigated. It was revealed that the improvement of wettability by preheating suppressed sputtering generation, and a surface having a small surface roughness was fabricated by SLM in a vacuum.

Study of atomic excitations in sputtering with targets partially covered with oxygen

International Nuclear Information System (INIS)

Weng, J.; Veje, E.

1984-01-01

We have bombarded pure, elemental targets of Be, B, Mg, Al, Si, Ti, and Au with 80 keV Ar + ions and studied excitation of sputtered atoms or ions under UHV conditions as well as with oxygen present at the target surface. The measurements on Mg, Al, Si, and Ti have been done at projectile incidence angles from 0 0 to 85 0 . Excitation probabilities for gold were found to be only very little influenced by oxygen, but for Be, B, Mg, Al, Si, and Ti, the excitation probabilities were in many, but not all, cases found to depend strongly on the oxygen pressure as well as on the beam current density. This indicates that the excitation mechanism is strongly dependent on the initial electronic conditions of the solid. (orig.)

Sputter deposited titanium disilicide at high substrate temperatures

Science.gov (United States)

Tanielian, M.; Blackstone, S.; Lajos, R.

1984-08-01

Titanium disilicide films were sputter deposited from a composite TiSi2.1 target on bare silicon wafers both at room temperature and at 600 °C. The room temperature as-deposited films require a 900 °C sintering step to reduce their resistivity. On the other hand, the as-deposited 600 °C films are fully reacted, polycrystalline, have no oxygen contamination, large grain sizes, and are oxidation resistant. Further annealing of these films at 900 °C produces no changes in their crystal structure, composition, resistivity, or grain size.

Hydroxyapatite formation on biomedical Ti–Ta–Zr alloys by magnetron sputtering and electrochemical deposition

Energy Technology Data Exchange (ETDEWEB)

Kim, Hyun-Ju [Department of Dental Materials, Research Center of Nano-Interface Activation for Biomaterials, and Research Center for Oral Disease Regulation of the Aged, School of Dentistry, Chosun University, Gwangju (Korea, Republic of); Jeong, Yong-Hoon [Biomechanics and Tissue Engineering Laboratory, Division of Orthodontics, College of Dentistry, The Ohio State University, Columbus, OH (United States); Choe, Han-Cheol, E-mail: hcchoe@chosun.ac.kr [Department of Dental Materials, Research Center of Nano-Interface Activation for Biomaterials, and Research Center for Oral Disease Regulation of the Aged, School of Dentistry, Chosun University, Gwangju (Korea, Republic of); Brantley, William A. [Division of Prosthodontics and Restorative Science, College of Dentistry, The Ohio State University, Columbus, OH (United States)

2014-12-01

The purpose of this study was to investigate hydroxyapatite formation on Ti-25Ta-xZr titanium alloys resulting from radio-frequency magnetron sputtering and electrochemical deposition. Electrochemical deposition of hydroxyapatite (HA) was first carried out using a cyclic voltammetry (CV) method at 80 °C in 5 mM Ca (NO{sub 3}){sub 2} + 3 mM NH{sub 4}H{sub 2}PO{sub 4}. Then a physical vapor deposition (PVD) coating was obtained by a radio-frequency (RF) magnetron sputtering technique. The microstructures, phase transformations, and morphologies of the hydroxyapatite films deposited on the titanium alloys were analyzed by optical microscopy (OM), X-ray diffractometer (XRD), energy dispersive X-ray spectroscopy (EDS) and field-emission scanning electron microscopy (FE-SEM). The morphologies of electrochemically deposited HA showed plate-like shapes on the titanium alloys, and the morphologies of the RF-sputtered HA coating had the appearance droplet particles on the plate-like precipitates that had formed by electrochemical deposition. For the RF-sputtered HA coatings, the Ca/P ratio was increased, compared to that for the electrochemically deposited HA surface. Moreover, the RF-sputtered HA coating, consisting of agglomerated droplet particles on the electrochemically deposited HA surface, had better wettability compared to the bulk titanium alloy surface. - Highlights: • Hydroxyapatite (HA) was deposited on Ti–Ta–Zr alloys by radio-frequency (RF) magnetron sputtering and a cyclic voltammetry. • The morphologies of the RF-sputtered HA coating on electrochemical deposits presented plate-like shapes with a droplet particle. • The Ca/P ratio for RF-sputtered HA coatings was greater than that for electrochemical deposited HA coatings. • The RF-sputtered and electrochemical HA coatings had superior wettability compared to the electrochemically deposited coatings.

Hydroxyapatite formation on biomedical Ti–Ta–Zr alloys by magnetron sputtering and electrochemical deposition

International Nuclear Information System (INIS)

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

2014-01-01

The purpose of this study was to investigate hydroxyapatite formation on Ti-25Ta-xZr titanium alloys resulting from radio-frequency magnetron sputtering and electrochemical deposition. Electrochemical deposition of hydroxyapatite (HA) was first carried out using a cyclic voltammetry (CV) method at 80 °C in 5 mM Ca (NO 3 ) 2 + 3 mM NH 4 H 2 PO 4 . Then a physical vapor deposition (PVD) coating was obtained by a radio-frequency (RF) magnetron sputtering technique. The microstructures, phase transformations, and morphologies of the hydroxyapatite films deposited on the titanium alloys were analyzed by optical microscopy (OM), X-ray diffractometer (XRD), energy dispersive X-ray spectroscopy (EDS) and field-emission scanning electron microscopy (FE-SEM). The morphologies of electrochemically deposited HA showed plate-like shapes on the titanium alloys, and the morphologies of the RF-sputtered HA coating had the appearance droplet particles on the plate-like precipitates that had formed by electrochemical deposition. For the RF-sputtered HA coatings, the Ca/P ratio was increased, compared to that for the electrochemically deposited HA surface. Moreover, the RF-sputtered HA coating, consisting of agglomerated droplet particles on the electrochemically deposited HA surface, had better wettability compared to the bulk titanium alloy surface. - Highlights: • Hydroxyapatite (HA) was deposited on Ti–Ta–Zr alloys by radio-frequency (RF) magnetron sputtering and a cyclic voltammetry. • The morphologies of the RF-sputtered HA coating on electrochemical deposits presented plate-like shapes with a droplet particle. • The Ca/P ratio for RF-sputtered HA coatings was greater than that for electrochemical deposited HA coatings. • The RF-sputtered and electrochemical HA coatings had superior wettability compared to the electrochemically deposited coatings

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

Photoelectrocatalytic property of microporous Pt-TiO2/Ti electrodes

International Nuclear Information System (INIS)

Hung, Chung-Hsuang; Wu, Kee-Rong; Yeh, Chung-Wei; Sun, Jui-Ching; Hsu, Chuan-Jen

2013-01-01

This study investigates the photoelectrocatalytic (PEC) property of microporous WO 3 -loaded TiO 2 /Ti layer, prepared via micro-arc oxidation (MAO) of Ti plate, followed by sputtering deposition of a thin Pt layer as a Pt-TiO 2 /Ti electrode. The WO 3 -loaded TiO 2 layer which is associated with a more acidic surface forms many local electrochemical cells on its micro-pores immersed in cationic dye solution. The electrocatalytic (EC) reactions can take place in the local cells by the applied electrons. A low resistivity that is accomplished by MAO technique and by platinization offers an easy path for the electron motions in the Pt-TiO 2 /Ti electrode. All these features make the EC oxidation of aqueous dye pollutants practically feasible without using counter electrodes and supporting electrolytes. Our experiments demonstrate that, under PEC condition, the Pt-TiO 2 /Ti shows the highest degradation rate constant of 0.83 h − 1 at an applied bias of 1.0 V and exhibits significantly high PEC and EC oxidation activities at a low applied bias of 0.25 V. This is attributable to high anodic currents generated in the Pt-TiO 2 /Ti even at low bias. The modified microporous electrodes conclusively reveal a very interesting EC property as a two double-sided device that functions the PEC and EC oxidation simultaneously without a need of supporting electrolyte and expensive Pt cathode. - Highlights: ► Pt-TiO 2 /Ti exhibits enhanced photoelectrocatalytic (PEC) activity at low applied bias. ► The proposed device uses low applied bias (< 1.0 V) with no explicit cathode. ► PEC oxidation can be performed without supporting electrolyte and Pt cathode

Optical properties of zinc titanate perovskite prepared by reactive RF sputtering

Science.gov (United States)

Müllerová, Jarmila; Šutta, Pavol; Medlín, Rostislav; Netrvalová, Marie; Novák, Petr

2017-12-01

In this paper we report results from optical transmittance spectroscopy complemented with data on structure from XRD measurements to determine optical properties of a series of ZnTiO3 perovskite thin films deposited on glass by reactive magnetron co-sputtering. The members of the series differ by the titanium content that was revealed as an origin of the changes not only in structure but also in dispersive optical properties. Low porosity has been discovered and calculated using the Bruggeman effective medium approximation. An apparent blue-shift of the optical band gap energies with increasing titanium content was observed. The observed band gap engineering is a good prospective for eg optoelectronic and photocatalytic applications of ZnTiO3.

Two-Functional Direct Current Sputtered Silver-Containing Titanium Dioxide Thin Films

Directory of Open Access Journals (Sweden)

Ditta IB

2009-01-01

Full Text Available Abstract The article reports on structure, mechanical, optical, photocatalytic and biocidal properties of Ti–Ag–O films. The Ti–Ag–O films were reactively sputter-deposited from a composed Ti/Ag target at different partial pressures of oxygen on unheated glass substrate held on floating potentialU fl. It was found that addition of ~2 at.% of Ag into TiO2film has no negative influence on UV-induced hydrophilicity of TiO2film. Thick (~1,500 nm TiO2/Ag films containing (200 anatase phase exhibit the best hydrophilicity with water droplet contact angle (WDCA lower than 10° after UV irradiation for 20 min. Thick (~1,500 nm TiO2/Ag films exhibited a better UV-induced hydrophilicity compared to that of thinner (~700 nm TiO2/Ag films. Further it was found that hydrophilic TiO2/Ag films exhibit a strong biocidal effect under both the visible light and the UV irradiation with 100% killing efficiency ofEscherichia coliATCC 10536 after UV irradiation for 20 min. Reported results show that single layer of TiO2with Ag distributed in its whole volume exhibits, after UV irradiation, simultaneously two functions: (1 excellent hydrophilicity with WDCA < 10° and (2 strong power to killE. colieven under visible light due to direct toxicity of Ag.

Characteristics of growth of complex ferroelectric oxide films by plasma-ion sputtering

Science.gov (United States)

Mukhortov, V. M.; Golovko, Yu. I.; Mukhortov, Vl. M.; Dudkevich, V. P.

1981-02-01

An experimental investigation was made of the process of growth of a complex oxide film, such as BaTiO3 or (Ba, Sr)TiO3, by plasma-ion sputtering. It was found that ion bombardment of a ceramic target knocked out neutral excited atoms. These atoms lost energy away from the target by collisions and at a certain critical distance hcr they were capable of oxidation to produce BaO, TiO, TiO2, and SrO. Therefore, depending on the distance between the cathode and the substrate, the “construction” material arrived in the form of atoms or molecules of simple oxides. These two (atomic and molecular) deposition mechanisms corresponded to two mechanisms of synthesis and crystallization differing in respect of the dependences of the growth rate, unit cell parameters, and other structural properties on the deposition temperature. The role of re-evaporation and of oxidation-reduction processes was analyzed.

Effect of Ti seed and spacer layers on structure and magnetic properties of FeNi thin films and FeNi-based multilayers