Hardness anisotropy and polarity in indium antimonide

Abstract

Hardness tests were performed on {111} and {001} faces of InSb in the temperature range 20–400°C. A Vickers indenter was used on the {111} faces; it was found that the In face was harder than the Sb face at all temperatures. This behaviour is related to the different mobilities of the In(g) and Sb(g) dislocations and fits a model previously developed for hardness polarity in GaAs. On the {001} faces, hardness anisotropy tests were carried out, using a Knoop indenter. At low temperatures, an anisotropy between ⟨110⟩ and ⟨110⟩ directions was detected. This behaviour is also related to the different mobilities of the two dislocation types, and fits a new model for flow patterns around Knoop indenters originally developed for Ge and GaAs, which attributes hardness anisotropy to the different work-hardening characteristics of different families of slip planes.