XPS Study of Pt/CexZr1−xO2/Si Composite Systems

1999 ◽  
Vol 581 ◽  
Author(s):  
A. Norman ◽  
R. Sporken ◽  
A. Galtayries ◽  
F. Mirabella ◽  
K. Keveney ◽  
...  
Keyword(s):  
Thin Films ◽  
Mixed Oxides ◽  
Incidence Angle ◽  
Grazing Incidence ◽  
Metallic State ◽  
Surface Reduction ◽  
Composite Systems ◽  
Reducing Conditions ◽  
Powder Samples ◽  
Xps Study

ABSTRACTThis work describes the study of the surface reduction of ceria zirconia mixed oxides (CeZrO) as either thin films or powders, both with and without Pt present. XPS was used to measure the composition of the surface and the oxidation states of all metals contained within the material. The thin films of CeZrO showed little reactivity towards the reducing conditions used. Grazing incidence angle XRD showed the presence of Ce0.75Zr0.25O2. The thin films prepared with Pt showed that surface reduction of Ce4+ occurred under reducing conditions. The size of the Pt clusters was also determined from the data. The Pt was found to always exist in the metallic state. The Zr4+ was not seen to change during all treatments. For the powder samples the Ce4+ was readily reduced to approximately 60%. Pt was found to be initially oxidised with the % of metallic Pt increasing with reduction temperature. Again no change in the Zr was observed.

Grazing incidence synchrotron x-ray diffraction method for analyzing thin films

1987 ◽  
Vol 2 (4) ◽  
pp. 471-477 ◽  
Author(s):  
G. Lim ◽  
W. Parrish ◽  
C. Ortiz ◽  
M. Bellotto ◽  
M. Hart
Keyword(s):  
Thin Films ◽  
Penetration Depth ◽  
Incidence Angle ◽  
Depth Profiling ◽  
Diffraction Method ◽  
Grazing Incidence ◽  
Parallel Beam ◽  
X Ray ◽  
Small Incidence ◽  
Iron Oxide Films

A method using synchrotron radiation parallel beam x-ray optics with a small incidence angle α on the specimen and 2Θ-detector scanning is described for depth profiling analysis of thin films. The instrumentation is the same as used for Θ:2Θ synchrotron parallel beam powder diffractometry, except that the specimen is uncoupled from the detector. There is no profile distortion. Below the critical angle for total reflection αc, the top tens of Angstroms are sampled. Depth profiling is controlled to a few Angstroms using a small α and 0.005° steps. The penetration depth increases to several hundred Angstroms as α approaches αc. Above αc there is a rapid increase in penetration depth to a thousand Angstroms or more and the profiling cannot be sensitively controlled. At grazing incidence the peaks are shifted several tenths of a degree by the x-ray refraction and an experimental procedure for calculating the shifts is described. The method is illustrated with an analysis of iron oxide films.

scholarly journals Déposition par Pulvé Risation Cathodique Radio Fréquence et Caracté Risation Électronique, Structurale et Optique de Couches Minces du Dioxyde de Titane

2004 ◽  
Vol 27 (3) ◽  
pp. 169-181 ◽  
Author(s):  
K. Hafidi ◽  
M. Azizan ◽  
Y. Ijdiyaou ◽  
E. L. Ameziane
Keyword(s):  
Thin Films ◽  
Titanium Oxide ◽  
Incidence Angle ◽  
Glass Structure ◽  
Grazing Incidence ◽  
Visible Range ◽  
Infrared Range ◽  
Oxide Thin Films ◽  
X Ray ◽  
Deposited Films

Deposited titanium oxide thin films are used as optical protector films for several materials and as energy converters for solar cells. In this work, titanium oxide thin films are deposited on c-Si and glass substrates by reactive radiofrequency sputtering. All the deposits are grown at ambient temperature and the sputtering gas is a mixture of oxygen and argon with an overall pressure of10−2mbar. The oxygen partial pressure ratios varies from 5% to 20%.Characterization of deposited films is made by grazing incidence X-ray diffraction (GIXD), grazing incidence X-ray reflection (GIXR), X-ray photoemission spectroscopy (XPS) and optical transmission spectroscopy. The characterization results reveal that deposited films of TiO2 are polycrystalline and present both rutile and anatase phases. The chemical composition of raw films in Ti:O ratio is equal to 1:2.02, and the titanium at surface is completely oxidized. In fact, the Ti2p core level behavior shows that the oxidization state of Ti is equal to+4.The specularily reflected intensity according to incidence angle of the X-ray on TiO2/glass structure shows one critical angle attributed to the TiO2 film equal to 0.283º. This angle value involves film density between rutile and anatase phases. The optical characterization shows that TiO2 thin films obtained are transparent in visible range, and have a refraction index value equal to 2.45 and when extrapolated to infrared range, it is equal to 2.23. The value of gap energy (3.35 eV) is deduced from variation of absorption coefficient versus incident radiation energy.

Anomalous peaks in grazing incidence thin film X-ray diffraction

1994 ◽  
Vol 9 (1) ◽  
pp. 44-49 ◽  
Author(s):  
Richard A. Vaia ◽  
Maura S. Weathers ◽  
William A. Bassett
Keyword(s):  
Thin Films ◽  
Incidence Angle ◽  
Incident Angle ◽  
Grazing Incidence ◽  
Sample Surface ◽  
X Ray ◽  
Polymeric Thin Films ◽  
Diffraction Geometry ◽  
Sample Orientation ◽  
Diffuse Surface

Numerous spurious X-ray peaks were encountered during grazing incidence angle diffractometer scans of ceramic and polymeric thin films on crystalline and amorphous substrate materials. At least three possible sources of spurious peaks are identified. (1) At (2θ) values greater than ∼ 10°, Laue reflections from characteristic and Bremsstrahlung continuum radiation produce spurious peaks with a (2θ) dependence on X-ray incident angle and sample orientation. At (2θ) values less than 10°, (2) specular X-ray reflection from a boundary between two media of different indices of refraction and (3) diffuse surface scattering produces spurious peaks with a dependence on X-ray incident angle and sample surface topography. From an understanding of the spurious peaks, improved experimental techniques may be developed. Because these peaks can interfere significantly with grazing incidence diffractometer scans, it is particularly important to those making studies of thin films by this asymmetric diffraction geometry to be aware of the existence and origins of these spurious peaks.

Evolution of short-range order in chemically and physically grown thin film bilayer structures for electronic applications

Nanoscale ◽  
2020 ◽  
Vol 12 (24) ◽  
pp. 13103-13112
Author(s):  
Ann-Christin Dippel ◽  
Olof Gutowski ◽  
Lars Klemeyer ◽  
Ulrich Boettger ◽  
Fenja Berg ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Short Range ◽  
Short Range Order ◽  
Incidence Angle ◽  
Grazing Incidence ◽  
Distribution Functions ◽  
Individual Layer ◽  
X Ray ◽  
Pair Distribution Functions

The local atomic structure of two stacked thin films is probed by applying grazing incidence x-ray total scattering at variable incidence angle and resolving pair distribution functions for each individual layer.

Characterization of Ferroelectric PZT Thin Films - Line Broadening Study (Using Grazing Incidence Geometry)

1991 ◽  
Vol 35 (A) ◽  
pp. 601-605
Author(s):  
Michael O. Eatough ◽  
Raymond P. Goehner ◽  
Thomas J. Headley ◽  
Bruce A. Tuttle
Keyword(s):  
Thin Films ◽  
Crystallite Size ◽  
Incidence Angle ◽  
Incident Angle ◽  
Grazing Incidence ◽  
Processing Parameters ◽  
Phase Changes ◽  
Incidence Geometry ◽  
Line Broadening

AbstractFerroelectric polycrystalline thin films are being pursued as materials for use in the next generation of radiation hardened nonvolatile semiconductor memories, optical switches and optical computers. Of particular interest are PZT films with a composition near the morphotropic phase boundary. In order to fully understand the the difference in electrical properties as a function of processing parameters it is necessary to fully characterize phase composition and crystallographic properties of these films. Since some films are produced by either spinning or dipping successive layers to obtain the desired thickness it was necessary to compare the properties of each layer.X-ray diffraction techniques employing parallel beam optics with grazing incidence angle geometry were used to characterize the films. Experimental procedures using sealed tube xray diffraction systems to determine differences in crystallite size and microstrain as a function of depth into the films are a rather unique application of this technique. Discerning the contribution to line broadening due to phase changes, grazing incident angle geometry, crystallite size and microstrain are key to the success of this technique.This paper discusses the experimental techniques employed and will demonstrate how we were able to successfully determine microstrain as a function of depth into the film. We use transmission electron microscopy (TEM) to aid in the characterization of the films. A brief description of the processing procedures used to produce the films is also provided.

Compositional depth profiling of polycrystalline thin films by grazing-incidence X-ray diffraction

2006 ◽  
Vol 39 (5) ◽  
pp. 683-696 ◽  
Author(s):  
I. M. Kötschau ◽  
H. W. Schock
Keyword(s):  
Thin Films ◽  
Incidence Angle ◽  
Grazing Incidence ◽  
Instrument Function ◽  
Cross Sectional ◽  
X Ray ◽  
Depth Profiles ◽  
Profile Matching ◽  
Diffraction Patterns ◽  
Modelling Approach

This paper uses an innovative peak profile matching method to determine compositional depth profiles of Cu(In,Ga)(S,Se)2thin films and other suitable solid-solution compounds. A layer absorption model allows the generation of grazing-incidence diffraction patterns on the basis of the known diffractometer instrument function, compositional depth profiles and the corresponding mass absorption characteristics. In contrast to other methods, the modelling approach exploits the information stored in the shape evolution of the peak profile as a function of incidence angle. A small number of diffraction patterns of the same peak are sufficient to track depth-dependent shifts of the principal lattice parameters. The method is adapted to the specific properties of the chalcopyrite Cu(In,Ga)(S,Se)2system. In fact, the multinary chalcopyrite compounds grown by physical vapour deposition have some remarkable properties which allow the successful application of the method. Issues like surface roughness, refraction at low incidence angles and their effects upon relative intensities can be successfully circumvented by the modelling approach. Ambiguities in the modelling results are very small and can be minimized by comparison with complementary depth profiles using secondary ion mass spectrometry or cross-sectional energy-dispersive X-ray analysis.

Quantifying Multiple Crystallite Orientations and Crystal Heterogeneities in Complex Thin Film Materials

2019 ◽  
Author(s):  
Jonathan Ogle ◽  
Daniel Powell ◽  
Eric Amerling ◽  
Detlef Matthias Smilgies ◽  
Luisa Whittaker-Brooks
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Structural Design ◽  
Grazing Incidence ◽  
Crystallite Orientation ◽  
Miller Index ◽  
X Ray ◽  
X Ray Scattering ◽  
Orientation Distributions ◽  
Orientation Information

<p>Thin film materials have become increasingly complex in morphological and structural design. When characterizing the structure of these films, a crucial field of study is the role that crystallite orientation plays in giving rise to unique electronic properties. It is therefore important to have a comparative tool for understanding differences in crystallite orientation within a thin film, and also the ability to compare the structural orientation between different thin films. Herein, we designed a new method dubbed the mosaicity factor (MF) to quantify crystallite orientation in thin films using grazing incidence wide-angle X-ray scattering (GIWAXS) patterns. This method for quantifying the orientation of thin films overcomes many limitations inherent in previous approaches such as noise sensitivity, the ability to compare orientation distributions along different axes, and the ability to quantify multiple crystallite orientations observed within the same Miller index. Following the presentation of MF, we proceed to discussing case studies to show the efficacy and range of application available for the use of MF. These studies show how using the MF approach yields quantitative orientation information for various materials assembled on a substrate.<b></b></p>

scholarly journals Is Reduced Strontium Titanate a Semiconductor or a Metal?

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 744
Author(s):  
Christian Rodenbücher ◽  
Christo Guguschev ◽  
Carsten Korte ◽  
Sebastian Bette ◽  
Kristof Szot
Keyword(s):  
Point Defect ◽  
Decisive Role ◽  
Thermal Reduction ◽  
Defect Chemistry ◽  
Oxygen Activity ◽  
Metallic State ◽  
Metallic Behavior ◽  
Reducing Conditions ◽  
History Play ◽  
Semiconducting Behavior

In recent decades, the behavior of SrTiO3 upon annealing in reducing conditions has been under intense academic scrutiny. Classically, its conductivity can be described using point defect chemistry and predicting n-type or p-type semiconducting behavior depending on oxygen activity. In contrast, many examples of metallic behavior induced by thermal reduction have recently appeared in the literature, challenging this established understanding. In this study, we aim to resolve this contradiction by demonstrating that an initially insulating, as-received SrTiO3 single crystal can indeed be reduced to a metallic state, and is even stable against room temperature reoxidation. However, once the sample has been oxidized at a high temperature, subsequent reduction can no longer be used to induce metallic behavior, but semiconducting behavior in agreement with the predictions of point defect chemistry is observed. Our results indicate that the dislocation-rich surface layer plays a decisive role and that its local chemical composition can be changed depending on annealing conditions. This reveals that the prediction of the macroscopic electronic properties of SrTiO3 is a highly complex task, and not only the current temperature and oxygen activity but also the redox history play an important role.

Evolution of Interfacial Roughness Correlations of Fe Au Films Grown on Mgo(001) Substrates

1996 ◽  
Vol 440 ◽  
Author(s):  
P. C. Chow ◽  
R. Paniago ◽  
R. Forrest ◽  
S. C. Moss ◽  
S. S. P. Parkin ◽  
...  
Keyword(s):  
Thin Films ◽  
Diffuse Scattering ◽  
Perfect Match ◽  
Grazing Incidence ◽  
Interface Roughness ◽  
Metallic Structures ◽  
X Ray ◽  
Dimensional Image ◽  
X Ray Scattering ◽  
Image Plate Detector

AbstractThe growth by sputtering of a series of thin films of Fe/Au on MgO(001) substrates was analyzed using Bragg and diffuse X-ray scattering. The Fe (bcc) layer grows rotated by 45° with respect to the MgO – Au(fcc) (001) epitaxial orientation, resulting in an almost perfect match between the two metallic structures. By collecting the X-ray diffuse scattering under grazing incidence using a 2-dimensional image plate detector, we mapped the reciprocal space of these films. We characterized the correlated interface roughness starting with a buffer of Fe in which only three interfaces are present. The propagation of the roughness was subsequently characterized for Fe/Au multilayers with 40 and 100 bilayers. We observe an enlargement of the surface features as a function of time, evidenced by the longer lateral cutoff length measured for thicker films.

Effects of rotation and ion incidence angle on sputter depth resolution in thin films of NiFe/Ta

1992 ◽  
Vol 19 (1-12) ◽  
pp. 55-59 ◽  
Author(s):  
Matthias M. Henneberg ◽  
Daryl J. Pocker ◽  
Michael A. Parker
Keyword(s):  
Thin Films ◽  
Incidence Angle ◽  
Depth Resolution ◽  
Effects Of Rotation
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