Direct observation of a lattice instability in heavily in-doped CdTe

The nearest-neighbor environment around Cd atoms in CdTe and CdTe doped with 5 and 8 at. % indium was determined from Cd K-edge x-ray-absorption fine-structure measurements. The first shell of neighbors is split into two distances R(1) = 2.58 +/- 0.02 Angstrom, and R(2) = 2.81 +/- 0.01 Angstrom, for the doped samples. The presence of the short distance R(1) = 2.58 Angstrom is related to the existence of lattice relaxations produced by the introduction of indium.