TDPAC Study of the In2Se3 Crystal Structure

摘要

The time-differential perturbed angular correlation (TDPAC) technique has been used to investigate the temperature dependence of the electric field gradient (EFG) at Cd impurities in the semiconducting compound In2Se3. Between room temperature and the melting point, four different phases could be observed. Most crystal structures which have been proposed for the alpha and beta phases are shown to be incorrect. The beta prime phase (550-720 C) has not been reported previously. The data suggests that the beta phase may be a Peierls distortion of the beta prime phase. The EFG in the alpha phase is well described by a simple point charge model suggesting that the electronic part of the EFG is alpha - In2Se3 is small.