Interfacial Coupling in Multiferroic-Ferromagnet Heterostructures

Abstract

We report local probe investigations of the magnetic interaction between BiFeO3 films and a ferromagnetic Co0.9Fe0.1 layer. Within the constraints of intralayer exchange coupling in the Co0.9Fe0.1, the multiferroic imprint in the ferromagnet results in a collinear arrangement of the local magnetization and the in-plane BiFeO3 ferroelectric polarization. The magnetic anisotropy is uniaxial, and an in-plane effective coupling field of order 10 mT is derived. Measurements as a function of multiferroic layer thickness show that the influence of the multiferroic layer on the magnetic layer becomes negligible for 3 nm thick BiFeO3 films. We ascribe this breakdown in the exchange coupling to a weakening of the antiferromagnetic order in the ultrathin BiFeO3 film based on our X-ray linear dichroism measurements. These observations are consistent with an interfacial exchange coupling between the CoFe moments and a canted antiferromagnetic moment in the BiFeO3.

References in corpus (5)

• Weak ferromagnetism and magnetoelectric coupling in bismuth ferrite
• Mechanisms of exchange bias with multiferroic BiFeO3 epitaxial thin films
• Tunnel magnetoresistance and robust room temperature exchange bias with multiferroic BiFeO3 epitaxial thin films
• Exchange bias driven by the Dzyaloshinskii-Moriya interaction and ferroelectric polarization at G-type antiferromagnetic perovskite interfaces
• Thickness-dependent polarization of strained BiFeO3 films with constant tetragonality

Cited by in corpus (5)

• 180 degree Ferroelectric Stripe Nanodomains in BiFeO3 Thin Films
• Deterministic manipulation of multi-state polarization switching in multiferroic thin films
• Symmetry-Tunable Environment in Functional Ferroic Heterostructures
• Coupling of ferromagnetic and antiferromagnetic spin dynamics in Mn${}_2$Au/NiFe thin-film bilayers
• Magnetic fingerprint of interfacial coupling between CoFe and nanoscale ferroelectric domain walls