Structural correlations of AsGeSe glasses

Bulk AsxGe40−xSe60 (with x=0, 10 and 20 at.%) glasses were prepared using the melt-quench technique. Short range order (SRO) was examined by X-ray diffraction using Cu(Kα) radiation in the wave vector interval 0.28⩽K⩽6.5 Å-1. For Ge40Se60 glass, the first sharp diffraction peak (FSDP) is located at K=1.0Å-1 and shifted to higher K-values with increasing As content. Consequently, the coherence length has a maximum value for the binary glass. The SRO parameters have been obtained from the total distribution function, T(r). The inter-atomic distances obtained from the first and second peak are, r1=2.37±0.01Å and r2=3.93±0.01Å, in good agreement with previous works. The fundamental structural unit of the studied glasses is the Ge-Se4/2 tetrahedral.