Search results for "sputter deposition"
showing 10 items of 93 documents
Changes in the local structure of nanocrystalline electrochromic films of hydrated nickel vanadium oxide upon ozone-induced coloration
2005
Hydrated thin films of nickel vanadium oxide (Ni1−xVxOy), made by reactive DC magnetron sputtering, were studied by x-ray absorption spectroscopy at the Ni and V K-edges using synchrotron radiation. The XANES signals were analysed within the full-multiple-scattering formalism, whereas EXAFS data were modelled within the multi-shell multiple-scattering approach. We found that transparent films exhibit a nanocrystalline NiO-type structure with homogeneous distribution of V ions substituting Ni ions. Exposure of the films to ozone resulted in dark brown coloration associated with an appearance of Ni3+ ions and accompanied by a modification of the local electronic and atomic structures of the V…
Fabrication and characterization of ZnO/Zn2TiO4/ZnAl2O4 composite films by using magnetron sputtering with ceramic targets
2022
Abstract Transparent conducting oxides (TCO), including ZnO/Zn2TiO4/ZnAl2O4 composite films, are of considerable importance in optoelectronic applications. We fabricated composite film assisted with DC magnetron sputtering using ceramic target material (ZnO, TiO2, and Al2O3 powders mixture). The influence of processing gases composition (0–50% O2–Ar) on film characteristics, including structural, optical, and electronic properties, is assessed. All films contain hexagonal wurtzite ZnO structure and ZnAl2O4, Zn2TiO4 spinel phases, with (002), (100), and (101) as dominant orientation by increasing oxygen contents. The transmittance of deposited films is above 81% (except for 50% oxygen), and …
In-situ electrochemical atomic force microscopy study of aging of magnetron sputtered Pt-Co nanoalloy thin films during accelerated degradation test
2016
Abstract A Pt-Co nanoalloy thin film catalyst was prepared by using simultaneous magnetron sputtering of Pt and Co. The catalyst was characterized during accelerated degradation test using in-situ electrochemical atomic force microscopy complemented with ex-situ techniques such as energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy and synchrotron radiation photoelectron spectroscopy. The combined results gave the full step-by-step picture of the catalyst behavior during the aging test.
Li intercalation in transparent Ti–Ce oxide films: Energetics and ion dynamics
1997
Films of Ti dioxide, mixed Ti–Ce oxide, and Ce dioxide were produced by reactive dc magnetron sputtering. Electrochemical lithiation was probed by chronopotentiometry, cyclic voltammetry together with optical transmittance recording, and impedance spectroscopy. Evidence was found for inserted electrons being accommodated in Ce 4f states; this contention was supported by preliminary results from x-ray absorption fine-structure spectroscopy. These electrons do not produce luminous electrochromism. The variation of the chemical diffusion coefficient of Li, with film composition and Li content, was also studied.
Investigation of La2O3 and/or (Co,Mn)3O4 deposits on Crofer22APU for the SOFC interconnect application
2009
International audience; Chromia forming alloys (stainless steels) are among the best candidates for SOFC interconnects. However, problems of decreasing electronic conductivity during high temperature service and volatility of chromium oxide scales need to be solved. Electronically conductive surface coatings, which also reduce oxide scale growth and chromium volatility, are needed to improve stainless steel interconnects. The goal of this study is to investigate combinations of lanthanum oxide (La2O3) and cobalt manganese oxide ((Co,Mn)3O4) coatings on Crofer22APU stainless steel. Thin film coatings of La2O3 (~200 nm) and Co,Mn (1:1) (~2 mm) were deposited via metal organic chemical vapor d…
Controlling the intralayer structure of Co/Pt superlattices
1999
Abstract The effect of the surface quality of MgO (1 1 1) substrates seeded by a 3 nm thick Pt layer on the intralayer and interlayer structure of Co/Pt (1 1 1) superlattices was investigated. The superlattices were grown by DC magnetron sputtering. Pre-growth processing of the MgO shows that intensive polishing using a specific H 2 O/SiO 2 suspension prior to growth is mandatory for obtaining long-range structural coherence in the films. The comparison between superlattices grown on re-polished and as-supplied substrates shows that the substrate treatment enhances the crystalline in-plane orientation and suppresses abc / acb twin formation. Magnetization measurements were performed using t…
Structural analysis of W3O/WO3 and TiO/TiO2 periodic multilayer thin films sputter deposited by the reactive gas pulsing process
2012
International audience; DC reactive sputtering was used to deposit titanium and tungsten-based metal/oxide periodic nanometric multilayers using pure metallic targets and Ar + O-2 gas mixture as reactive atmosphere. The innovative technique namely, the reactive gas pulsing process allows switching between the metal and oxide to prepare a periodic multilayered structure with various metalloid concentrations and nanometric dimensions. The same pulsing period was used for each deposition to produce metal-oxide periodic alternations close to 10 nm. Structure, crystallinity and chemical composition of these films were systematically investigated by Raman spectroscopy, X-ray diffraction and Energ…
Epitaxial films of the magnetic shape memory material
2007
Abstract By DC-sputtering from a stoichiometric target onto sapphire substrates we prepared epitaxial films of Ni 2 MnGa . X-ray diffraction in two circle geometry shows only the Ni 2 MnGa peaks corresponding to a (1 1 0) oriented growth on the (1 1 0) oriented sapphire substrate. Rocking curve scans shows that the out of plane orientation has a width of only 1 . 1 ∘ . By four circle X-ray diffraction we find an in-plane aligned growth. The Curie temperature as determined by SQUID magnetometry is 368 K. On cooling down the low field magnetization drops at around 260–280 K indicating the austenite to martensite transition. The presence of two different phases at high and low temperature also…
<title>Micromechanical properties of AIN, TiN, and AIN/TiN nanostructured multilayer coatings</title>
2003
Coatings of AlN, TiN and nanostructured multilayer AlN/TiN have been deposited by reactive sputtering on sapphire, tungsten carbide (WC) and stainless steel substrates. The microhardness, adhesion and formation of cracks under indentation tests, were investigated. It was found that the adhesion of coatings on steel was higher, than on WC for all investigated samples. Nanostructured multilayer AlN/TiN films have the best adhesion and fracture toughness both on the hard (WC) and on the soft (stainless steel) substrates if compared with that for AlN and TiN "single layer" coatings. The effect of γ-radiation on mechanical properties of transparent AlN films was investigated. After the exposure …
Growth and size distribution of Au nanoparticles in annealed Au/TiO2 thin films
2014
Abstract Nanocomposites consisting of noble metal nanoparticles (NPs) embedded in TiO2 thin films are of great interest for applications in optoelectronics, photocatalysis and solar-cells for which the plasmonic properties of the metal NPs play a major role. This work investigates the first stages of the formation of gold NPs by thermal annealing of Au-doped TiO2 thin films grown by magnetron sputtering. A low concentration of gold in the films is considered (5 at.%) in order to study the first stages of the formation of the NPs. Raman spectroscopy is used to follow the crystallization of TiO2 when increasing the annealing temperature. In addition, low-frequency Raman scattering (LFRS) is u…