Investigation of the activation parameters of low-temperature slip in anthracene single crystals

Abstract

In 1990 Kojima and Okada reported their observations on the temperature dependence of the yield-stress and of the activation-volume in anthracene single crystals for (001) [010] and (001) [110] slip systems in the range 80 to 370 K. Their data have been examined within the framework of the kink-pair nucleation model of plastic flow, which was originally proposed by Fletham for body-centred cubic metals, and has recently been improved and further developed by Butt. The observed interdependences of yield stress, activation volume and temperature for anthracene single crystals in the range 80 to 200 K are found to be fully explicable in terms of the model referred to, in which slip is considered to be induced by stress-assisted thermally activated formation of arcs of screw dislocations trapped in Peierls troughs.