Interpretation of the vacancy-ordering controlled growth morphology of Hg5In2Te8 precipitates in Hg3In2Te6 single crystals by TEM observation and crystallographic calculation

The growth morphology and detailed crystallography of Hg5In2Te8 precipitates in Hg3In2Te6 matrix to has been interpreted by means of transmission electron microscopy and invariant element deformation model. Three crystallographic equivalent variants of Hg5In2Te8 precipitates in Hg3In2Te6 matrix were found to have different growth directions and habit planes. Such growth morphology is fully attributed to the lattice shrinkage induced by vacancy ordering under high temperature in Hg5In2Te8. Through near coincident site lattice and invariant strain calculation, the morphology and crystallographic features of the precipitate has been successfully interpreted.