Spatially resolved strain-imprinted magnetic states in an artificial multiferroic

Abstract

Artificial multiferroic systems, in which novel properties can emerge from elastic coupling between piezoelectric and magnetostrictive phases, are a promising route to obtain significant room-temperature magnetoelectric coupling at the nanoscale. In this work, we have used element-specific soft x-ray photoemission electron microscopy to spatially resolve the effects of ferroelectric BaTiO 3 on the magnetic properties of ferromagnetic layers of CoFe 2 O 4 and NiFe 2 O 4 . Resulting from the large magnetoelastic anisotropy present in these artificial multiferroic systems, a modification of the orientation and symmetry of the magnetic easy axes of the ferromagnetic film upon changing the underlying domain structure of the ferroelectric has been observed. This opens the possibility to strain-imprint magnetic states in these systems.

Film size-dependent voltage-modulated magnetism in multiferroic heterostructures

“…Specifically, how do we understand the influence of the FE domain (ferroelastic) switching on both the static magnetic domain (wall) morphology and its dynamic evolution process? Recent works have reported such mutual magnetic-FE domain coupling in FE crystal-based multiferroic heterostructures, such as CoFe/(001)BTO [67,68,96], CoFeB/(001)PMN-PT [97], and more recently in CoFe 2 O 4 (or NiFe 2 O 4 )/(100)BTO [69], but the results in multiferroic magnetic/FE composite thin films are still lacking.…”

Influence of elastically pinned magnetic domain walls on magnetization reversal in multiferroic heterostructures

“…Other promising strategies to locally tailor the magnetic properties of a continuous magnetic medium exploit either exchange coupling with a multiferroic BiFeO 3 layer [13][14][15][16] or strain coupling to the ferroelastic domains of a ferroelectric BaTiO 3 substrate * sebastiaan.van.dijken@aalto.fi [17][18][19][20][21][22][23]. Although stemming from different mechanisms, both latter approaches result in one-to-one correlations between the domains in BiFeO 3 or BaTiO 3 and the domains of an adjacent ferromagnetic film.…”

Determination of the cation site distribution of the spinel in multiferroic CoFe 2 O 4 /BaTiO 3 layers by X-ray photoelectron spectroscopy

“…The ferroelectric perovskite BaTiO 3 coupled with the ferrimagnetic spinel CoFe 2 O 4 is a well referenced system for the study of the magnetic states upon multiferroic couplings [1,2]. Such a study requires to fully analyze the magnetic properties of the spinel of such systems, among them the spinel inversion factor.…”