The effect of a magnetic field upon dislocation de-pinning from paramagnetic obstacles was studied. It was suggested that the de-pinning could take place according to a mechanism in which, when a kink passed an obstacle, the unsaturated electron bonds of the kink and the obstacle formed a radical pair. Magnetic field-induced intercombination transitions, from a binding to anti-binding state, of the radical pair led to an additional population of high-spin anti-binding states with a lower binding energy. This resulted in increased plasticity. A strong dependence of the amplitude-dependent internal function of dislocations upon the magnetic field was predicted.

Spin Effects in Plasticity. M.Molotskii, V.Fleurov: Physical Review Letters, 1997, 78[14], 2779-82