Temperature control of local magnetic anisotropy in multiferroic CoFe/BaTiO3

TL;DR

This study investigates how temperature-induced phase transitions in BaTiO3 substrates influence the local magnetic anisotropy and domain patterns in CoFe films, revealing reversible and irreversible magnetic switching behaviors.

Contribution

It demonstrates temperature-controlled manipulation of magnetic anisotropy in multiferroic heterostructures through phase transitions of BaTiO3.

Findings

Stripe domains are preserved during temperature changes.

Magnetic easy axes rotate at specific phase transitions.

Irreversible ferromagnetic domain pattern changes occur after cycling.

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 degrees. Irreversible changes in the ferromagnetic domain pattern are induced when the room-temperature ferroelectric domain structure is altered after temperature cycling.