Detailed investigations on short- and intermediate-range structures of Ge-Se glasses near the stiffness transition composition

細川 伸也*; 川北 至信; Pusztai, L.*; 池田 一貴*; 大友 季哉*

Journal of the Physical Society of Japan, 90(2), p.024601_1 - 024601_12, 2021/02

https://doi.org/10.7566/JPSJ.90.024601

In order to improve the reliability of short- and intermediate-range atomic structures of GeSe glasses, high quality neutron diffraction data, in both the real and reciprocal spaces, were added to the existing anomalous X-ray scattering and X-ray diffraction datasets [Hosokawa et al., Phys. Rev. B 84, 014201 (2011)] for reverse Monte Carlo modeling. This addition proved to be highly effective for obtaining well-refined structural data and for revealing a close relationship between the compositional stiffness transition occurring at about = 0.20-0.26 and the partial structures. Although the and functions gradually change with varying , important indications on the stiffness transition are confirmed on the basis of the intermediate-range element-selective atomic structures () more clearly than it was possible by previous results. An abrupt decrease in terms of the the prepeak intensity of , a rapid disappearance of the Ge-Ge homopolar bonds, anomalies in the ratio of edge- and corner-sharing Ge(Se) tetrahedra, and characteristic changes in the tetrahedral connections with decreasing X across the so-called intermediate phase have all been observed.