The present paper puts forward the hypothesis that the yield point and dislocation velocity of tetrahedrally coordinated semiconductors exhibited two different temperature domains, with a transition from the low-temperature to the high-temperature regime at approximately 60% of the absolute melting point. In the literature this aspect has not received much attention, and model parameters obtained in both domains were traditionally mixed together. The reason may be sought in the fact that, for experimental demands in most cases, the yield point was generally measured in the high-temperature regime, while the dislocation velocity was investigated in the low-temperature domain. This leads to a problem insofar as the lower yield stress (in the high-temperature regime) usually obeys an exponential temperature and a power-law strain-rate dependence, while the dislocation velocity (in the low-temperature regime) showed a more complicated dependence on stress and temperature in several cases, with activation energy and stress exponent depending on stress and temperature respectively. In the present paper the available measurements were reanalysed by taking into account that only data obtained in the same temperature range were compared. In this context, investigations of the dislocation velocities of Si, Ge and InSb extending to homologous temperatures well above 0.6, which had not attracted much interest in the literature, play a decisive role.

Yield Point and Dislocation Velocity of Diamond and Zincblende Semiconductors at Various Temperatures. H.Siethoff: Philosophical Magazine A, 2002, 82[7], 1299-316