Temperature control of local magnetic anisotropy in multiferroic CoFe/BaTiO3

Abstract

This paper reports on the temperature evolution of local elastic interactions between ferromagnetic CoFe films and ferroelectric BaTiO3 substrates. Polarization microscopy measurements indicate that growth-induced stripe domains in the CoFe films are preserved and strengthened during cooling and heating through the structural phase transitions of BaTiO3. Moreover, rotation of the magnetic easy axes at the tertragonal-to-orthorhombic transition (T = 278 K) and at T ≈ 380 K simultaneously switches the local magnetization of both uniaxial domains by 90°. Irreversible changes in the ferromagnetic domain pattern are induced when the room-temperature ferroelectric domain structure is altered after temperature cycling.