Skip to main content

Short and intermediate range order of Ge20Se80−xTex glasses

Research Authors
A. H. Moharram,M. A. Hefni, A. M. Abdel-Baset
Research Abstract

The total structure factor, S(K), have been obtained for the chalcogenide Ge20Se80−xTex (where x =0, 10, 20, and 30 at. %) glasses using x-ray diffraction in the wave vector interval 0.28<=K
<=6.87 Å−1. The appearance of the first sharp diffraction peak in the structure factor indicates the presence of the intermediate range order. The radii of the first- and second-coordination shells
(r1 , r2) are increased linearly with Te addition. The large covalent radius of Te atom in compare with that of Se atom was behind the above linear increase. The first coordination number shows
insignificant changes with Te content. The obtained values of r1 / r2 ratio and the corresponding bond angle (theta) indicate that the structural units inside the present alloys are Ge(Se1/2)4 tetrahedra
connected by chains of the chalcogen atoms. Raman spectra confirm the above conclusion and in the same time exclude the existence of Ge(Te1/2)4 tetrahedra. Based on the chemical ordered network mode, Te–Te bonds are responsible for the different behavior of Te-rich (30 at. %) glass from others.

Research Department
Research Journal
JOURNAL OF APPLIED PHYSICS
Research Publisher
American Institute of Physics
Research Rank
1
Research Vol
108
Research Year
2010
Research Pages
073505