Study of etch pits on (111) surface of Hg₃In₂Te₆ crystal

Etch pits on the (111) face of Hg₃In₂Te₆ sample etched by modified Chen solution are investigated by means of scanning electron microscopy, scanning probe microscopy and electron backscatter diffraction instrument. The experimental results show that there are three basic etch pits: line shape, shuttle shape and date shape. In addition, black lines which are (111) plane projections of grooves in the latter two etch pits are oriented in three directions which are at 120° angles to one another. Further analyses show that the formation process of the three etch pits can be explained by the model of double cross-slip of screw dislocation.