Anisotropy of Selected Mechanical Properties of PbTe

Abstract

Selected mechanical properties are investigated for single PbTe crystals using the nanoindentation method. A few values of maximum load from 5 to 50 mN were selected for the measurements using the Berkovich form of the indenter. The nanohardness and Young's modulus for (100), (110), and (111)‐oriented planes are determined for the bulk crystal grown by self‐selecting vapor growth (SSVG) and characterized by X‐ray diffraction. The values of nanohardness and Young's modulus for a thick, MBE‐grown, (111)‐oriented PbTe layer deposited onto BaF2 substrate obtained for the comparison, using maximum load from 1 to 20 mN, indicate a difference between the mechanical properties of bulk crystal and thick MBE‐grown layer of the same material. The results suggest a much higher nanohardness value of the MBE‐grown layer than that of the bulk crystal. The values resulting from all measurements are compared with those given by theoretical predictions and a few existing experimental data.