Thermomagnetic instability of metal-insulator phase boundary

We consider diffusion of a magnetic field into a substance, which undergoes a metal-insulator phase transition under Joule heating. A development of a thermomagnetic instability of the interphase boundary is studied analytically and numerically. Solid solution (V/sub 1-x/Cr/sub x/)/sub 2/O/sub 3/ is taken as a model substance. In the non-linear stage the instability development shows a universal behavior that is independent on a shape of the initial disturbance.