A simple model based upon dislocation theory allows the construction of a fully defined system of differential equations and the calculation of curves that correspond to different mechanical tests such as stress relaxation, the creep test and the imposed strain rate test. Various multiplication and exhaustion rates of mobile dislocations were considered. The numerical solution of the system reproduces satisfactorily experimental curves obtained in Ge single crystals at 750 K.

Searching for the Proper Law of Dislocation Multiplication in Covalent Crystals. J.Fikar, B.Viguier, T.Kruml, C.Dupas: Journal of Physics - Condensed Matter, 2002, 14[48], 12887-95