A study was made of the effect of the Ca impurity concentration in NaCl crystals, and of the X-irradiation of NaCl and LiF crystals, upon the magnetic saturation field, B0. The latter characterized a transition from the normal proportionality, l  B2, of the dislocation mean path length to l = constant, where B was the magnetic induction. The value of B0 was shown to increase with the Ca concentration in NaCl crystals, and with the X-irradiation dose of NaCl and LiF. This indicated that dislocation breakaway from local defects in weak magnetic fields was controlled by longitudinal spin relaxation in a system of radical pairs that formed due to interactions between dislocation cores and paramagnetic centers.

Effect of Point Defect Concentration in NaCl and LiF Crystals on the Saturation Field of the Magnetoplastic Effect. E.V.Darinskaya, E.Hartmann: Physics of the Solid State, 2003, 45[11], 2115-8