Mechanical properties of pure and doped InP single crystals determined under local loading

The mechanical properties of pure and doped (Fe, Zn, Sn) InP single crystals have been investigated in the temperature range 293–600 K. It is shown that impurity hardening (increase in microhardness) is much more pronounced at high temperatures than at room temperature because of the retardation of moving dislocations by impurities, which is strongest at high temperatures. Appreciable scratch hardness anisotropy on the (001) face of the experimental crystals at 293 K was observed. It decreases rapidly as the temperature increases in the interval 293–600 K. It is shown that the 110] and directions on the (001) face of the experimental crystals are nonequivalent. The observed phenomena are explained by the different contributions of the two mechanisms of plastic deformation: slip and twinning in the process of scratch formation along the 〈100〉 and 〈110〉 directions, and along the 110] and directions. Fiz. Tekh. Poluprovodn. 31, 243–246 (February 1997)