Magnetoplastic effect in nonmagnetic crystals

The main features of the magnetoplastic effect displaying itself in dislocation displacements in nonmagnetic crystals under the action of external magnetic field are briefly discussed. The influences of external electric field and X-ray irradiation on the magnetoplastic effect are demonstrated for NaCl and LiF crystals. A magnetic induction threshold B-c below which the magnetoplastic effect does not exist is predicted and experimentally observed in Al, NaCl and LIF crystals. The existence of a threshold is associated with the fact that for B < B-c the spin-lattice relaxation time tau(sl) in a system is less than the time required for a spin evolution in a magnetic field resulting in the removal of the spin forbiddenness of a process that 'switches off'' the dislocation-pinning-center interaction. It is shown that the threshold field B-c is sensitive to temperature and X-ray irradiation of the samples. (C) 1997 Elsevier Science S.A.