Mutual regulation of polarization and magnetization in BFCNT/BFCO heterostructure via stress analysis of dipoles

The ability to mutually regulate polarization and magnetization, highly desirable for future multifunctional devices, remains elusive despite extensive investigations. In this work, a concept of mutual regulation of ferroelectric and ferromagnetic orders via stress analysis of dipoles was proposed and the idea was demonstrated in a 2-2 type multiferroic Bi6Fe1.6Co0.2Ni0.2Ti3O18/Bi2FeCrO6 heterostructure fabricated by a sol-gel technique followed with a rapid thermal proces. Both ferroelectricity, ferromagnetism and magnetoelectric coupling of the composite thin film were studied by macro- and microscale measurements. It demonstrated that a reversible change in domain structure does occur while exerting a stress on dipoles by different applied fields, wherein the (inverse)-piezoelectric effect, magnetostriction, Lorentz force, and Hall effect play an important role in deflection of dipoles and evolution of domains, and thus the regulation of polarization and magnetization, making it attractive for novel memories.