Local control of magnetic anisotropy in transcritical permalloy thin films using ferroelectric BaTiO_3 domains

摘要

We investigated the local coupling between dense magnetic stripe domains in transcritical permalloy (tPy) thin films and ferroelectric domains of BaTiO_3 single crystals in a tPy/BaTiO_3 heterostructure. Two distinct changes in the magnetic stripe domains of tPy were observed from the magnetic force microscopy images after cooling the heterostructure from above the ferroelectric Curie temperature of BaTiO_3 (120 ℃) to room temperature. First, an abrupt break in the magnetic stripe domain direction was found at the ferroelectric a-c-domain boundaries due to an induced change in in-plane magnetic anisotropy. Second, the magnetic stripe domain period increased when coupled to a ferroelectric a-domain due to a change in out-of-plane magnetic anisotropy. Micromagnetic simulations reveal that local magnetic anisotropy energy from inverse magnetostriction is conserved between in-plane and out-of-plane components.