Strain-coupled domains in BaTiO3(111)−CoFeB heterostructures

Abstract

The coupling of ferroelectric and ferromagnetic order holds promise for the realization of low-energy voltage-controlled multiferroic devices. Here, the authors show that using a (111)-oriented BaTiO${}_{3}$ substrate it is possible to create two distinct strain-coupled regions in a deposited CoFeB film, in which the in-plane magnetic easy axis rotates by either 60 or 120 degrees. These regions, which exist side by side in a sample heterostructure, contain different magnetic domain wall structures that exhibit different dependences on magnetic field.