Application of Differential Anomalous X-Ray Scattering to Structural Studies of Amorphous Materials

Abstract

A differential anomalous x-ray scattering technique has been developed for structural studies of disordered and amorphous systems. The results on amorphous GeSe 2 are consistent with the twofold coordination of Se and the fourfold coordination of Ge. The results on amorphous GeSe are consistent with threefold-coordinated models of the structure but not with the fourfold-twofold models.

Reverse Monte Carlo simulations, Raman scattering, and thermal studies of an amorphous Ge30Se70 alloy produced by mechanical alloying

“…4 and 1, indicating that the IRO in the alloy produced by MA is less pronounced than in the MQ-GeSe 4 samples 1,4 . The FSDP is known to be much dependent on Ge-Ge and, to a lesser extent, on Ge-Se correlations 3,14,47,48 . Therefore these correlations have a different behavior in MA-a-GeSe 4 .…”

“…This peak is associated with the FSDP in the S(K) shown in Fig. 2 and, since the FSDP is known to be strongly dependent on the Ge-Ge correlations and, to a lesser extent, on the Ge-Se correlations 14,47,48 , the low intensity FSDP experimentally observed in Fig. 2 could be caused by weak Ge-Ge and Ge-Se correlations at its position.…”

An Improved Regularization Technique for Analysis of Anomalous X-ray Scattering Data; Platinum Uridine Blue Sulfate as an Example

“…The air scattering was quite prominent at k < 2 A-l but diminished rapidly at larger k. The experimental intensity curves were corrected for absorption and normalized to absolute scale with the large angle method. Normalization involved determination and subtraction of fluorescence in the data and subtraction of the calculated Compton intensity (KroghMoe, 1956;Norman, 1957;Fuoss et al, 1981). The energy-independent atomic form factors and incoherent scattering functions were taken from International Tables for X-ray Crystallography (1974).…”

“…Our aim was to obtain more precise information about the Pt-unit structure by solving the Pt-Pt partial structure factor. The differential anomalous scattering (DAS) technique (Shevchik, 1977;Fuoss, Eisenberg, Warburton & Bienenstock, 1981) was also applied for obtaining more accurate Pt-Pt distances by comparing the total and differential radial distribution functions (RDF, DDF).…”

Molecular bond selective x-ray scattering for nanoscale analysis of soft matter

“…Anomalous scattering has been extensively used in the hard x-ray spectral range to tune the strength and phase of scattering from specific elements to resolve the phase problem in crystallography (10) and separate pair distribution functions in binary systems (11), and to enhance magnetic scattering (12). In the soft x-ray range resonant scattering has been used up to now in hard condensed matter to enhance magnetic (13) and charge (14) scattering, and to study charge, orbital, and spin ordering in complex oxides (15).…”