Analysis of high-energy x-ray diffraction data at high pressure: the case of vitreous As2O3 at 32 GPa

作者：Mei Q^*; Benmore C J; Soignard E; Amin S; Yarger J L

来源：Journal of Physics: Condensed Matter , 2007, 19(41): 415103.

DOI：10.1088/0953-8984/19/41/415103

The x-ray structure factor of vitreous As2O3 has been measured at 32 GPa in a laser-perforated diamond anvil cell using a monochromatic, micro-focused high-energy x-ray beam. The experimental correction procedures are discussed in detail, and they yield reliable data over the range Q = 0.3-13.5 angstrom(-1). The use of modified form factors to analyse the scattering data is presented to account for charge transfer. Analysis of the radial distribution function yields an increase in the coordination number from 3.1 +/- 0.3 oxygen atoms surrounding an arsenic atom at normal pressure to 4.8 +/- 0.5 at 32 GPa with only a slight change in the As - O bond length. Substantial structural changes are observed at higher distances, extending up to 18 angstrom in real space.

• 出版日期2007-10-17