Grazing-incidence x-ray photoemission spectroscopy investigation of oxidized GaAs(100): A novel approach to nondestructive depth profiling

Author(s):  
M. J. Chester
Nanoscale ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 752-761 ◽  
Author(s):  
Axel Wilson ◽  
Aude Bailly ◽  
Romain Bernard ◽  
Yves Borensztein ◽  
Alessandro Coati ◽  
...  

Au–Cu bimetallic nanoparticles (NPs) grown on TiO2(110) have been followed in situ using grazing incidence X-ray diffraction and X-ray photoemission spectroscopy from their synthesis to their exposure to a CO/O2 mixture at low pressure (P < 10−5 mbar) and at different temperatures (300 K–470 K).


1991 ◽  
Vol 35 (A) ◽  
pp. 143-150 ◽  
Author(s):  
T. C. Huang

AbstractGrazing-incidence X-ray analysis techniques which are commonly used for the nondestructive characterization of surfaces and thin films are reviewed. The X-ray reflectivity technicue is used to study surface uniformity and oxidation, layer thickness and density, interface roughness and diffusion, etc. The grazing-incidence in-plane diffraction technique is used to determine in-plane crystallography of epitaxial films. The grazing-incidence asymmetric-Bragg diffraction is used for surface phase identification and structural depth profiling determination of polycrystalline films. Typical examples to illustrate the types of information that can be obtained by the techniques are presented.


1988 ◽  
Vol 3 (2) ◽  
pp. 351-356 ◽  
Author(s):  
Michael F. Toney ◽  
Ting C. Huang ◽  
Sean Brennan ◽  
Zophia Rek

A nominally γ-Fe2O3 thin film (oxidized from an Fe3O4 film) has been structurally depth profiled using x-ray scattering in a grazing incidence, asymmetric Bragg geometry. By varying the grazing incidence angle, the x-ray penetration depth is varied from tens of Angstroms to several thousand Angstroms, slightly larger than the film thickness. At small incidence angles a diffraction pattern characteristic of α-Fe2O3 is observed, while at larger angles the pattern is predominantly from γ-Fe2O3, showing that there is a surface layer of α-Fe2O3. These results are quantified and the thickness of the α phase found to be 90 Å. The presence of the α phase explains a nonferromagnetic layer observed previously. These data together with magnetic and chemical data suggest that the nonferromagnetic layer forms during oxidation of the Fe3O4 film due to outward diffusion of Fe ions and their subsequent oxidation to form α-Fe2O3


1987 ◽  
Vol 2 (4) ◽  
pp. 471-477 ◽  
Author(s):  
G. Lim ◽  
W. Parrish ◽  
C. Ortiz ◽  
M. Bellotto ◽  
M. Hart

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.


2008 ◽  
Vol 595-598 ◽  
pp. 797-804 ◽  
Author(s):  
Cezarina C. Mardare ◽  
Michael Spiegel ◽  
Alan Savan ◽  
Alfred Ludwig

Ternary Mn-Co-Fe metallic thin films were deposited by RF-magnetron co-sputtering on SiO2/Si wafers and on ZMG232L (Hitachi Metals®), a special ferritic stainless steel for Solid Oxide Fuel Cell applications. The deposition was followed by heat treatment in an oxidizing atmosphere in order to convert the metallic thin films to (Mn,Co,Fe)3O4 spinel oxides. Coated and uncoated steel samples were analyzed after 1 h heat treatment in order to confirm the presence of the spinel structure on top of the steel, as well as to investigate and characterize the growth of oxides, namely (Mn,Cr)3O4 and Cr2O3, at the internal steel/coating interface. From Grazing Incidence X-ray Diffraction (GI-XRD) investigations together with Energy Dispersive X-ray analysis – Scanning Electron Microscopy and Time of Flight – Secondary Ions Mass Spectroscopy sputtering depth profiling the presence of well adherent (Mn,Co,Fe)3O4 coatings with approximately 500 nm thickness and a grain size of about 150 nm was confirmed. After the preparation annealing, some samples were heat-treated in simulated cathodic atmospheres at 800 °C for 500 h in order to assess the stability of the coatings. GI-XRD spectra still showed the presence of the protective coatings, however sputtering depth profile analysis indicated the presence of Cr on the surface.


1993 ◽  
Vol 317 ◽  
Author(s):  
Sandra G. Malhotra ◽  
Z. Rek ◽  
M. Vill ◽  
O.P. Karpenko ◽  
S.M. Yalisove ◽  
...  

ABSTRACTIt is important that inherent strains (or stresses) be controlled during thin film processing. This study used grazing incidence x-ray scattering (G1XS) to determine the strain gradient present in a ∼1700 Å sputtered molybdenum thin film. In particular, the gradient in the hydrostatic strain was Measured. This observation corresponded to assessing the average change in the lattice parameter as a function of depth throughout the thickness of the film. In addition, the strain ellipsoids, which represent the state of strain in three dimensions, were calculated as a function of film depth. It was shown that the strain varied throughout the ∼1700 Å Mo film thickness and that the principal strains were anisotropic, with one principal strain much larger than the others in Magnitude.


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