Ionic and electronic transport in In2S3 studied via perturbed angular correlation spectroscopy

We report on Perturbed Angular Correlation measurements in polycrystalline In2S3 samples in the temperature range from 8 K to 1000 K where two different crystallographic phases beta and alpha occur. As probes, implanted In-111 nuclei have been used. The three observed EFGs are attributed to probes residing substitutionally in the different sulfur-octahedra and -tetrahedra of beta-In2S3. A strong damping between 150 K and 300 K has been attributed to EFG fluctuations following the In-111(EC)Cd-111 decay. The alpha-phase (above 680 K) is characterized by a different dynamical damping of the perturbation functions, caused by mobile In atoms. Therefore, the semiconductor In2S3 shows, in two different temperature ranges, dynamical PAC-spectra which correspond to different types of mobile charge carriers. Since In-111 is a self atom in In2S3, this compound is an ideal substance to study the charge transport phenomena by the PAC technique.