MAGNETOPLASTIC EFFECT IN NONMAGNETIC CRYSTALS

The main features of the magnetoplastic effect displaying itself in di slocation displacements in nonmagnetic crystals under the action of ex ternal magnetic field are briefly discussed. The influences of externa l electric held and X-ray irradiation on the magnetoplastic effect are demonstrated for NaCl and LiF crystals. A magnetic induction threshol d B-c below which the magnetoplastic effect does not exist is predicte d and experimentally observed in Al, NaCl and LIF crystals. The existe nce of a threshold is associated with the fact that for B < B-c the sp in-lattice relaxation time tau(sl) in a system is less than the time r equired for a spin evolution in a magnetic held resulting in the remov al of the spin forbiddenness of a process that 'switches off'' the dis location-pinning-center interaction. It is shown that the threshold fi eld B-c is sensitive to temperature and X-ray irradiation of the sampl es. (C) 1997 Elsevier Science S.A.