PLASTIC-DEFORMATION, EXTENDED STACKING-FAULTS AND DEFORMATION TWINNING IN SINGLE-CRYSTALLINE INDIUM-PHOSPHIDE .1. UNDOPED INP

Undoped InP single crystals were deformed by compression in dual and multislip conditions at low shear strain rate (approximately 2 x 10(-5) s-1) and moderate temperature (approximately 0.4 T(m)). Transmission electron microscope observations of samples deformed to a few per cent strain have shown extended faulted areas in the activated slip planes. Intrinsic as well as extrinsic and mixed character stacking faults were observed. No twins were detected. Intrinsic faults could result from the anisotropic mobility of Shockley partials, but the applied stress level was too low for extended faults to be formed without internal stresses. Extrinsic faults were probably nucleated at triple nodes when attractive junctions formed as a result of dual slip. Their development could be explained by assuming that the partials which limit them have a very low mobility, because of their core structure distributed over two adjacent atomic planes. It seems that, like in other III-V compounds, stacking fault energy is smaller for extrinsic than for intrinsic faults.