Tuning magnetoelectric effect in Bi6Fe1.6Co0.2Ni0.2Ti3O18/La0.7Sr0.3MnO3/Bi6Fe1.6Co0.2Ni0.2Ti3O18 sandwich films employing micromagnetic moments and force on dipole

Abstract

Mutual modulating ferroelectric polarization and magnetization provides the potential for realizing new-type low-energy consumption, high-density memory, and logic processors. Despite extensive investigations, the underlying mechanism remains elusive. In this work, we employed Bi6Fe1.6Co0.2Ni0.2Ti3O18 (BFCNT) as the ferroelectric phase and La0.7Sr0.3MnO3 (LSMO) as the ferromagnetic phase to form environmentally friendly BFCNT/LSMO/BFCNT sandwich films fabricated on flexible FTO substrates using the all-solution chemical-solution deposition route. The ferromagnetism, ferroelectricity, and magnetoelectric coupling effect of the sandwich films were investigated by measuring at macro and micro scales. Then a dynamic micromagnetic moment model and a dipole force model were proposed to study the intermodulation of both ferromagnetism and ferroelectricity. It suggested that the combination of magnetic and electric moments makes the deflection of magnetization (or polarization) and a shift of the electron orbit, causing the movement of domain walls and the flip of magnetic domains, and thus a decrease of the saturation magnetization, offering new insights into the underlying physics of ME coupling in the model system.