Schottky defect energies in CsCl structure type crystals

Abstract

The Schottky defect formation energies (hs) of seven CsCl structure crystals have been calculated, following the Mott and Littleton method, considering the second neighbour repulsions and the van der Waals interactions explicitly. The computed hs values (in eV) for CsCl, CsBr, CsI, TlCl, TlBr, NH4Cl and NH4Br are 1.860, 1.744, 1.407, 1.269, 1.204, 1.205 and 1.171 respectively. The results indicate that with a satisfactory model of cohesive parameters, the Mott and Littleton procedure yields reliable estimates of defect energies which are compatible with experiments.