Frequency dependence of magnetoelectric effect in epitaxial La0.7Sr0.3MnO3/BaTiO3 bilayer film

The epitaxial La0.7Sr0.3MnO3/BaTiO3 bilayer film was deposited on (0 0 1) oriented SrTiO3 single-crystal substrate by pulsed laser deposition. The bilayer film possessed inherent ferromagnetic, ferroelectric properties. The frequency dependence of magnetoelectric (ME) voltage coefficient revealed a strong ME coupling from 0.1 kHz to 100 kHz. The value of ME voltage coefficient (αE) was around 213 mV/cm Oe at 1 kHz, which was at least one order of magnitude higher than other reports in the similar structure due to the rather low dielectric constant of BTO film. The measured value of αE corresponded to the theoretical expectation when interface coupling coefficient was 0.88.