Interaction of anti-site defects with Ge impurity atoms in Sb2Te3 single crystals

Sb2Te3 single crystals are synthetized doped with germanium in the concentration range up to 13%. The lattice parameters of these crystals are measured and found to show anomalous behaviour in the range of low Ge concentrations. On the basis of changes observed in the bonding parameters and using the variations of the plasma resonance frequency values of the crystals with Ge content, the anomalous behaviour of the lattice parameters is accounted for as a consequence of the interaction of anti-site Sb′Te defects with Ge atoms built into the lattice.