Efficient Electrical Manipulation of the Magnetization Process in an Epitaxially Controlled Co2FeSi/BaTiO3 Multiferroic Interface

We investigate the magnetic properties of an epitaxial full-Heusler ${\mathrm{Co}}_{2}\mathrm{Fe}\mathrm{Si}$ film with an atomically controlled multiferroic interface coupled with a ${\mathrm{Ba}\mathrm{Ti}\mathrm{O}}_{3}$ substrate. The real-space observation of the magnetic domain structure using a magneto-optical Kerr microscope reveals perfect domain-pattern transfer from the ferroelectric substrate, indicating strong interface magnetoelectric coupling. The unique anisotropic magnetization reversal process was found to be induced by lateral modulation of the magnetic anisotropy constant through the strain-induced magnetoelectric coupling effect. The strong interface coupling yields efficient electrical manipulation of the magnetic property with the appropriate initial ferroelectric domain pattern. Our finding indicates that the interface multiferroic structure based on an epitaxially grown Heusler thin film is a promising approach for efficient electrical manipulation of magnetization.