Direct measurement of magnetoelectric exchange in self-assembled epitaxial BiFeO_3-CoFe_2O_4 nanocomposite thin films

摘要

We report the direct measurement of a magnetoelectric (ME) exchange between magnetostrictive CoFe_2O_4 nanopillars in a piezoelectric BiFeO_3 matrix for single-layer nanocomposite epitaxial thin films grown on (001) SrTiO_3 substrates with SrRuO_3 bottom electrodes. The ME coefficient was measured by a magnetic cantilever method and had a maximum value of ～20 mV/cm Oe. The films possessed saturation polarization (60 μC/cm~2) and magnetization (410 emu/cc) properties equivalent to bulk values, with typical hysteresis loops.