Temperature dependence of the flow stress of III-V compounds.

An interpretation for the temperature dependence of the plastic flow stress of III-V compounds is presented, invoking only non-dissociated screw dislocations. With the aid of the Stillinger-Weber potential for the interatomic interaction, the Peierls potential of a non-dissociated screw dislocation is deduced in twodimensional space normal to the dislocation line. A saddle-point configuration and the formation energy of a kink pair are calculated in three-dimensional space. The relation obtained between the flow stress τ[sub c] and temperature T under a constant strain rate describes the experimental τ[sub c] T relation of III-V compound well: a strong T dependence at high τ[sub c] and low T, a stronger T dependence at low τ[sub c] and high T, and a plateau-like τ[sub c] at intermediate T. The hump in the τ[sub c] T relation is interpreted as a transition between different paths of the non-dissociated screw dislocation: a planar path and a zigzag path in the (111) plane. [ABSTRACT FROM AUTHOR]