X-Ray Diffraction Intensity Ratios I(111)/I(3¯11) of Natural Heulandites and Clinoptilolites

1998 ◽  
Vol 46 (6) ◽  
pp. 679-686 ◽  
Author(s):  
Fahri Esenli
1987 ◽  
Vol 2 (2) ◽  
pp. 96-98 ◽  
Author(s):  
Jacques Renault

AbstractXRF and XRD measurements made on a single pressed powder briquet can be combined to give more quantitative information than either technique employed alone. Speed of analysis and simplification of sample preparation are also enhanced. The algorithm presented here uses multiple linear regression of the concentrations of one or more elements on the corrected X-ray diffraction intensities of the phases containing them. The data reduction program runs on a microcomputer. Data are presented to show its application to mineralogical analysis of artificial mixtures of quartz, microcline (a feldspar) and calcite.


1999 ◽  
Vol 06 (05) ◽  
pp. 847-850 ◽  
Author(s):  
A. G. NORRIS ◽  
C. A. LUCAS ◽  
R. McGRATH ◽  
F. SCHEDIN ◽  
G. THORNTON ◽  
...  

Alkali metal coadsorption systems represent a step along the pathway from simple model adsorbate overlayers to more technologically relevant real systems. However, such is their complexity that very few systems have been structurally determined. Here we present a surface X-ray diffraction investigation of one of these systems, Ni (100)-(3×3)- (Cs+O) . Here a structural determination is particularly challenging due to the presence of three species in the surface layers and by the size of the unit cell. As a first step, anomalous scattering has been used to determine whether there is a contribution of the nickel substrate to the fractional order diffraction intensity. Measurements of the fractional order rods at 10 eV and 200 V below the nickel K edge (8333 eV) were used to probe the nickel contribution to the fractional order rods. It was found that the intensity of the scattering was unchanged, indicating that the fractional order peaks are caused by scattering from the coadsorbates only. This shows that the nickel surface layers are not changed by the adsorption and thus sets a useful constraint on the number of possible structures.


1997 ◽  
Vol 502 ◽  
Author(s):  
T. Guo ◽  
C. Rose-Petruck ◽  
R. X. Jimenez ◽  
J. A. Squier ◽  
B. C. Walker ◽  
...  

ABSTRACTX-ray diffraction, employing a table-top, laser-driven x-ray source, has been used to investigate laser-material interactions with simultaneous picosecond and subatomic range distance resolution. The x-ray source, consisting of a table-top terawatt laser system and a moving Cu wire target apparatus, generates ˜ 5 × 1010 photons (4π steradians s)−1 of Cu Kα radiation. The lattice dynamics of the (111) planes of GaAs single crystals has been studied after the crystal is exposed to intense femtosecond laser pulses. The diffraction results have yielded information about the timescale of the lattice dynamics in the picosecond range and an upper limit for the width of the xray pulses. Initial strain, defined as the percentage of lattice distortion resulted from the laser illumination, is as high as 0.25% and is followed by an exponential decay with a time constant of ˜ 150 ps. Increases in the diffraction intensity after the laser irradiation have also been observed, likely due to a transition from dynamic to kinematic diffraction associated with degradation of the crystal.


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