Study on the Amorphous Structure of Se-GeSe2 Alloys by X-ray Diffraction

The amorphous structure of Se-GeSe2 alloys quenched from the melt was investigated by means of X-ray diffraction method. The structure factor a(K) and the radial distribution function (RDF) of the alloys were calculated from the intensity function I(K). The following conclusions are drawn from these results.(1) The interatomic distance and the coordination number of pure Se agree well with those of Henninger et al.(2) In the a(K) of 33.3 at% Ge alloy, there is a strong peak corresponding to the strongest reflexion of the crystalline GeSe2, which indicates the close relation between the amorphous and the crystal structure of GeSe2.(3) Interatomic distances of the first and the second nearest neighbours slightly depend on the alloy composition. The coordination number increases gradually from 1.9 for pure Se to 2.6 for 33.3 at% Ge with Ge concentration.(4) Spiral atomic chain in the crystal of pure Se and Se alloys seems to persist in their amorphous structures.