Voltage-Induced Changes in Magnetism of FeCo/BaTiO₃ Thin Films Studied by X-Ray Absorption Spectroscopy

Abstract

Voltage-induced changes in the magnetic properties of FeCo thin films grown on a BaTiO₃ substrate are investigated by means of the X-ray magnetic circular dichroism (XMCD). The magnetization curves show different effects of the applied voltages depending on the Fe-Co compositions, which are ranging from Fe₆₇Co₃₃ to Fe₂₅Co₇₅. The XMCD spectra suggest that magnetization of the Fe₅₀Co₅₀ film at the saturation state are different between the positive and negative applied voltages, while those for other compositions have no detectable dependence on the applied voltage. The peculiar behavior for Fe₅₀Co₅₀ could be related to the abrupt change in the density of state at the Fermi level. [DOI: 10.1380/ejssnt.2015.465]