Impact of magnetization and hyperfine field distribution on high magnetoelectric coupling strength in BaTiO${}_3$-BiFeO${}_3$ multilayers

Abstract

Understanding the mechanisms of magnetoelectric (ME) coupling within multiferroic structures is paramount from a fundamental as well as an applied point of view. We report here that the magnetoelectric properties, as well as the magnetization, of BaTiO${}_3$-BiFeO${}_3$ superlattices can be tuned by varying the BiFeO${}_3$ layer thickness. The magnetoelectric voltage coefficient (${\alpha }_{ME}$) reaches its maximum of 60.2 Vcm${}^{-1}$Oe${}^{-1}$ at 300 K, one of the highest values reported so far, for a sample with a BiFeO${}_3$ thickness of 5 nm and a BaTiO${}_3$ thickness of 10 nm. To gain deeper insight into the increased magnetoelectric coupling, and both the local and macroscopic magnetic properties, samples with varying BiFeO${}_3$ thicknesses have been investigated. Correlations were established between the hyperfine field (HFF), the magnetoelectric voltage coefficient and the magnetization. The possible mechanisms responsible for the strong magnetoelectric coupling are discussed.

References in corpus (2)

• Room temperature coexistence of large electric polarization and magnetic order in BiFeO3 single crystals
• Periodicity-dependence of the ferroelectric properties in BiFeO3/SrTiO3 multiferroic superlattices