Berkovich nanoindentation on InP

In this study, the pressure-induced deformation mechanisms of single-crystal InP(1 0 0) are investigated by using nanoindentation with a Berkovich diamond indenter, micro-Raman spectroscopy and the cross-sectional transmission electron microscopy (XTEM) techniques. The load-displacement curves show the multiple "pop-ins" phenomena during nanoindentation loading. The cracking patterns are found from the scanning electron microscopy (SEM) observations within the mechanically deformed regions. In addition, no evidence of nanoindentation-induced phase transformation is observed up to a maximum indentation load of 200 mN, as revealed from the micro-Raman spectra. Therefore, it is demonstrated that dislocations dominate the deformation mechanisms and, no phase transformation occurs. Form XTEM observations, the slip bands are oriented at an angle of 45° to the sample surface (1 0 0), indicating that slip deformation of InP occurs within the {1 1 1} planes. The mechanical deformation processes are observed in InP closely related to the coupling of the dislocation-mediated; plasticity, nucleation and propagation of slip (twinning).