共查询到10条相似文献,搜索用时 62 毫秒
1.
The oxygen interaction with Ni silicide surfaces in a wide range of composition, from NiSi2 to Ni3Si, has been investigated at room temperature by AES and XPS techniques. It has been found that the Si oxidation is enhanced over that of pure Si in all the Ni-Si compounds, and that the strongest oxidation occurs in Ni richer silicides. In general, oxygen bonds with Si leaving the metal unoxidized, but in Ni3Si evidence for the occurrence of Ni oxidation has been found at high exposures. 相似文献
2.
Nd-Fe-B is a promising material system for the preparation of thin films with good hard magnetic properties. One problem of this material class is the sensitivity against oxidation, resulting in a degradation of the magnetic properties. Using XPS depth profiling in combination with peak-shape analysis it is shown that already after several hours oxygen can diffuse deep into the thin laser-deposited films and that Nd is mainly responsible for the oxidation. Local element analysis with AES revealed boron inhomogeneities from droplet formation during laser deposition. These problems can be solved by using a capping Cr layer and an FeB target for thin film preparation, respectively. 相似文献
3.
In this paper we present the results of the XPS atomic depth profile analysis, using ion beam sputtering, of L-CVD SnO2 thin films grown on an atomically clean SiO2 substrate after annealing at 400 °C in dry atmospheric air. From the evolution of the Sn 3d5/2, O 1s, Si 2p and C 1s core level peaks our experiments allowed the determination of the in depth atomic concentration of the main components of the SnO2/SiO2 interface. Thin (few nm) nearly stoichiometric SnO2 films are present at the topmost layer of the thin films, and progressive intermixing with SnO and silicon oxide is observed at deeper layer. The interface between the Sn and the Si oxide layers (i.e. the effective Sn oxide thickness) is measured at 13 nm. 相似文献
4.
Amorphous Zr-Cu-Ni-Al-[Ti, Nb] ribbons prepared by melt spinning under argon atmosphere were subjected to electrochemical investigations. Passive films developed at potentiostatic anodic polarization in sulphuric acid solution were investigated by Auger electron spectroscopy (AES) and sputter depth profiling.Changes in the shape of the Auger peaks have been analyzed by factor analysis of the spectra obtained during depth profiling. Pronounced changes in shape and position occur for the Zr, Al, and Ti Auger transitions, but not for Cu and Ni. At least three different peak shapes for O(KVV) were found and attributed to different oxygen binding states. The alloy composition has no significant effect on the thickness and composition of the oxide layer.In multi-element alloys preferential sputtering is a common phenomenon. In the steady state of sputtering, a significant depletion in Cu is found. At the oxide/metal interface, a distinct enrichment of copper is found for all alloys and treatments. The degree of this Cu enrichment depends on the pretreatment. It is higher for the electrochemically-passivated samples than for samples with oxide layers grown during melt spinning. 相似文献
5.
A.A. Wronkowska A. Wronkowski A. Bukaluk M. Trzciński K. Okulewicz 《Applied Surface Science》2007,253(7):3367-3371
In/Pd and Pd/In/Pd thin films were prepared by thermal evaporation on the SiO2 substrate in a vacuum. The structural and optical properties of the films were investigated by means of X-ray diffractometry (XRD), Auger electron spectroscopy (AES) and spectroscopic ellipsometry (SE). Auger depth profile studies were performed in order to determine the composition of elements in the Pd-In systems. Interdiffusion of metals was detected at room temperature. Optical properties of Pd-In composite layers formed due to the interdiffusion were derived from ellipsometric quantities Ψ and Δ measured in the photon energy range 0.75-6.50 eV at different angles of incidence. The effective optical spectra show absorption peaks dependent on the composition of nonuniform films. The XRD patterns indicated formation of Pd1−xInx intermetallic phases in the samples. 相似文献
6.
G. Bouyssoux M. Romand H.D. Polaschegg J.T. Calow 《Journal of Electron Spectroscopy and Related Phenomena》1977,11(2):185-196
The surface composition and the thickness of anodic passive films formed on chromium electrodes in sulphuric acid baths have been studied by XPS and AES using Ar+—ion sputtering. The results are consistent with a 13–16-Å thick oxide layer of composition close to Cr2O3. Some evidence is also given concerning hydrated species located in the outermost part of the passive film. 相似文献
7.
The evolution of the interface between organosilicate glass (OSG) and sputter deposited Ta or TaN films has been characterized by X-ray phototelectron spectroscopy (XPS). Cross-sectional TEM (XTEM) was also used to analyze Ta/OSG and TaN/OSG/interfaces for samples formed under different deposition conditions. XPS data show that Ta deposition onto OSG results in formation of an interphase between 1 and 2 nm thick composed of oxidized Ta and C. Metallic Ta is then formed on top of the interfacial region. In contrast, Ta-rich TaN formation occurs with some nitridation of the substrate, but with no significant interphase formation. The XPS data are consistent with the XTEM data. The XTEM results for Ta/OSG indicate a spatially irregular interface over a length scale of ∼2 nm, while results for TaN/OSG indicate a spatially abrupt region. 相似文献
8.
9.
Davor Pavuna Daniel Ariosa Dominique Cloetta Claudia Cancellieri Mike Abrecht 《Pramana》2008,70(2):237-243
Since 1997 we systematically perform direct angle resolved photoemission spectroscopy (ARPES) on in-situ grown thin (<30 nm) cuprate films. Specifically, we probe low-energy electronic structure and properties of high-T
c superconductors (HTSC) under different degrees of epitaxial (compressive vs. tensile) strain. In overdoped and underdoped
in-plane compressed (the strain is induced by the choice of substrate) ≈15 nm thin La2 − x
Sr
x
CuO4 (LSCO) films we almost double T
c to 40 K, from 20 K and 24 K, respectively. Yet the Fermi surface (FS) remains essentially two-dimensional. In contrast, ARPES
data under tensile strain exhibit the dispersion that is three-dimensional, yet T
c drastically decreases. It seems that the in-plane compressive strain tends to push the apical oxygen far away from the CuO2 plane, enhances the two-dimensional character of the dispersion and increases T
c, while the tensile strain acts in the opposite direction and the resulting dispersion is three-dimensional. We have established
the shape of the FS for both cases, and all our data are consistent with other ongoing studies, like EXAFS. As the actual
lattice of cuprates is like a ‘Napoleon-cake’, i.e. rigid CuO2 planes alternating with softer ‘reservoir’, that distort differently under strain, our data rule out all oversimplified two-dimensional
(rigid lattice) mean field models. The work is still in progress on optimized La-doped Bi-2201 films with enhanced T
c.
相似文献
10.
Angle resolved XPS (ARXPS) is a powerful tool for the determination of the thickness of ultra-thin films. In the case of high-k dielectric layers, the technique is capable of measuring the thickness of both the high-k layer and intermediate layers of silicon dioxide or metal silicate. The values for layer thickness are in close agreement with those generated by a variety of other techniques. As well as knowing the thickness of these layers, it is important to determine whether the layers are continuous or whether the coverage of the high-k layer is only partial. Using ARXPS, a method has been developed to determine whether the coverage of the high-k material is continuous and, if not, to calculate the fraction of the surface that is covered. The method is described with reference to the layers of Al2O3 grown on SiO2 using atomic layer deposition (ALD). The method is then applied to HfO2 layers produced using ALD on silicon wafers whose surfaces had received three different types of surface treatment. The way in which the layers grow and the nature of the resulting layer were found to depend upon the pre-treatment method. For example, growth on a thermal silicon dioxide surface resulted in complete coverage of HfO2 after fewer ALD cycles than layers grown on an H-terminated surface. The results from ARXPS are compared with those obtained from ToF SIMS that have been shown earlier to be a valuable alternative to the LEIS analysis [1]. 相似文献