Fig. 1. (a) Schematic of Cu/CoO_1–δ/Co/Cu stack grown on PMN-PT(110) substrate and the configuration used for applying an electric field. (b) Cross-sectional TEM image of the stack.

Fig. 2. (a) The ZFC magnetic hysteresis loops measured with magnetic fields applied along the [1 – 10] and [001] directions. (b) A schematic of the strain induced in the PMN-PT (110) substrate with the applied electric field. (c) The dependence of the ZFC magnetic hysteresis loops along the [1 – 10] direction upon the applied electric fields. (d) The electric field dependence of the H_C extracted from the hysteresis loops in (c).

Fig. 3. (a) Angular dependence of hysteresis loops of the CoO_1–δ/Co bilayer. (b) The extracted H_E and H_C as functions of the angle. (c) and (d) The angular dependence of the hysteresis loops and the extracted H_E(C) calculated with the M–B model.

Fig. 4. The voltage dependence of hysteresis loops after the FC procedure along (a), (b) the [1 – 10] direction and (c), (d) the [001] direction. The hysteresis loops at positive voltages show similar behavior with those at negative voltages.