Structure of Alpha GeTe

Abstract

The parameters in the crystal structure of α-GeTe were determined by least-squares analysis of intensity data obtained with an automatic x-ray powder diffractometer. The rhombohedral cell containing 4 Ge and 4 Te atoms has a=5.996±0.001 Å, α=88.18°, and the single atom-position parameter x=0.237±0.002. The displacement of one sublattice with respect to the other from the relative position that would correspond to the NaCl structure (i.e., x=0.250) corroborates the predictions, based on band calculations, of Cohen, Falicov, and Golin.