X-Ray Diffraction under Specular Reflection Conditions on Crystals with an Amorphous Surface Film

1984 ◽  
Vol 81 (1) ◽  
pp. 47-53 ◽  
Author(s):  
P. A. Aleksandrov ◽  
A. M. Afanasiev ◽  
M. K. Melkonyan ◽  
S. A. Stepanov
1997 ◽  
Vol 30 (1-2) ◽  
pp. 71-79 ◽  
Author(s):  
Liu Yu-Shu ◽  
Zhao Yu

A simple and convenient X-ray diffraction method is proposed to determine the thickness of surface film for textured specimens. The analysis result for a synthetic specimen with surface film has proved that the method is applicable and reliable.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
M. Shahabi-Navid ◽  
Y. Cao ◽  
J. E. Svensson ◽  
A. Allanore ◽  
N. Birbilis ◽  
...  

AbstractThe surface film on pure magnesium and two aluminium-containing magnesium alloys was characterised after 96 h at 95% RH and 22 °C. The concentration of CO2 was carefully controlled to be either 0 or 400 ppm. The exposed samples were investigated using X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and electron microscopy. The results showed that when the alloys were exposed to the CO2-containing environment, aluminium cations (Al3+) was incorporated into a layered surface film comprising a partially “hydrated” MgO layer followed by Mg(OH)2, and magnesium hydroxy carbonates. The results indicated that aluminium-containing magnesium alloys exhibited considerably less localised corrosion in humid air than pure magnesium. Localised corrosion in the materials under investigation was attributed to film thinning by a dissolution/precipitation mechanism.


2002 ◽  
Vol 716 ◽  
Author(s):  
N. Hata ◽  
Y. Oku ◽  
K. Yamada ◽  
T. Kikkawa

AbstractWe propose and demonstrate experimentally a structural characterization technique for ultra-low-dielectric-constant thin films with periodic porous structures [1-3] by employing X-ray diffraction / scattering measurements. The analytical approach that we propose here takes into account specular reflection, incoherent scattering from random distribution of electron density, and coherent scattering from periodically modulated distribution of electron density. From the analysis, inter-pore distances and pore diameters in the directions perpendicular and parallel to the film surface are determined with which the film porosity is calculated. Thus obtained porosity is then used to discuss the film density and dielectric constant in comparison to those of non-porous reference sample.


1996 ◽  
Vol 452 ◽  
Author(s):  
D. Buttard ◽  
G. Dolino ◽  
D. Bellet ◽  
T. Baumbach

AbstractHigh resolution X-ray diffraction and reflectivity have been used for the structural characterization of thin porous silicon layers of p and p+ doping type. Thin porous silicon layers studied either by diffraction or reflectivity, in the range of 10–1000 nm, exhibit several thickness fringes, corresponding to a lateral homogeneity of the layer thickness. The comparison between the experimental results with simulations enables one to deduce structural information relative to the porosity, thickness, lattice parameter as well as interface thickness. For p+ type samples a double fringe system was observed, showing the existence of a surface film probably at the porous silicon layer top surface.


1985 ◽  
Vol 18 (1) ◽  
pp. 27-32 ◽  
Author(s):  
P. A. Aleksandrov ◽  
A. M. Afanas'ev ◽  
A. L. Golovin ◽  
R. M. Imamov ◽  
D. V. Novikov ◽  
...  

1988 ◽  
Vol 108 (1) ◽  
pp. 129-133 ◽  
Author(s):  
G. Wallner ◽  
E. Burkel ◽  
H. Metzger ◽  
J. Peisl

2002 ◽  
Vol 17 (3) ◽  
pp. 712-717 ◽  
Author(s):  
Rosa M. Torres Sánchez ◽  
A. Boix ◽  
R. C. Mercader

After gibbsite was milled for 5 min in a Cr-steel oscillating mill, corundum was obtained by heating the powder for 3 h at 800 °C. We found that iron contamination, produced by the milling process, is essential to attain the transformation at this low temperature and is located at the surface of the gibbsite particles. The knowledge of the oxidation state and location of the contaminant elements, necessary to control the solid-state reactions and/or phase transformations induced by the milling, was realized in this work by a characterization performed by chemical analysis, x-ray photoelectron spectroscopy, Mössbauer spectroscopy, and isoelectric point determination. The iron contamination amounted to about 3% (as Fe2O3) for the sample milled for 60 min. That the iron contamination that occurred mainly on the gibbsite amorphous surface was concluded after a comparison of the isoelectric point determination of the milled samples with that of a mechanical mixture of gibbsite and hematite. X-ray diffraction studies showed that gibbsite looses its crystallinity after the first 5 min of milling.


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