EXAFS and negative thermal expansion in CdTe

CdTe is affected by a low-temperature negative thermal expansion (NTE) of the lattice parameter, whose strength and temperature interval are intermediate between those of the iso-structural crystals Ge and CuCl. EXAFS measurements have been performed on CdTe from 19 to 300 K. The first-shell analysis has led to an accurate evaluation of the bond thermal expansion and of the parallel and perpendicular MSRDs. The values of the relevant parameters measured by EXAFS for CdTe are intermediate between the corresponding values previously found for Ge and CuCl.