Voltage control of magnetic single domains in Ni discs on ferroelectric BaTiO 3

For 1 mu m-diameter Ni discs on a BaTiO3 substrate, the local magnetization direction is determined by ferroelectric domain orientation as a consequence of growth strain, such that single-domain discs lie on single ferroelectric domains. On applying a voltage across the substrate, ferroelectric domain switching yields non-volatile magnetization rotations of 90 degrees, while piezoelectric effects that are small and continuous yield non-volatile magnetization reversals that arc non-deterministic. This demonstration of magnetization reversal without ferroelectric domain switching implies reduced fatigue, and therefore represents a step towards applications.