Magnetomigration in granular cobalt-copper films deposited by the ion-plasma method

We have studied the effect of a constant magnetic field on the structure and composition of cobalt-copper (Co-Cu) granular alloy films deposited by the ion-plasma method. The phenomenon of magnetomigration of the main components and impurities has been observed. A necessary condition for this effect is a high mobility of adatoms, which has been achieved by ion-plasma deposition onto hot (200°C) substrates at high energies of incident metal ions. Under the action of an external magnetic field with strength above 300 Oe, both diamagnetic and paramagnetic adatoms migrate in opposite directions perpendicular to the field lines. Using this effect, it is possible to obtain thin magnetic films possessing high diamagnetic susceptibility and having a low content of undesired impurities (chlorine, hydrogen, carbon, argon, etc.).