New results on the phase transformations of In2Se3

The various phases and the phase transformations of In2Se3 are studied by electron microscopy and electron diffraction methods. Specimens from crystal slices perpendicular to the hexagonal basal plane were used. The results were combined with those reported by J. van Landuytet al. (1) for specimens parallel to the basal plane. It is found that the various α(n)-polytypic forms of In2Se3 follow similar transformation paths by heating above room temperature. The ultimate δ-phase is cation disordered with a wurtzite-like average structure. Apart from the γ-phase, the intermediate phases are characterized by highly faulted sequences of structure sheets along thec-axis.