Multiferroic interfaces composed of d0 perovskites oxides

TL;DR

This paper explores how doping and ferroelectric polarization at KTaO3/PbTiO3 interfaces induce tunable ferromagnetism and magnetoelectric effects, offering new pathways for multiferroic device development.

Contribution

It demonstrates that carrier doping and polarization reversal at these interfaces can induce and control ferromagnetism, revealing a novel multiferroic mechanism beyond traditional materials.

Findings

Doped carriers induce ferromagnetism at interfaces.

Ferromagnetism can be tuned by ferroelectric polarization.

Electric field can switch magnetic states at the interface.

Abstract

We investigate the electronic, ferroelectric and magnetic properties of KTaO3/PbTiO3 interfaces by using conventional density functional theory (DFT) and advanced DFT such as hybrid functional HSE06. We show that doped holes in valence bands or electrons in conduction bands give rise to ferromagnetism at the interfaces. The ferromagnetic states are ground states for both hole-doped (p-type) and electron-doped (n-type) interfaces by comparison with their corresponding nonmagnetic and antiferromagnetic states. Carriers (holes or electrons) concentrate near the interface to screen the polarization charge and thus the concentration of carrier varies with the ferroelectric polarization. Furthermore, the interface magnetization, which is nearly proportional to the concentration of carrier, can be tuned by ferroelectric polarization reversal, leading to strong intrinsic magnetoelectric effects at the interface of originally nonmagnetic KTaO3 and PbTiO3. Interestingly, a ferromagnetic-nonmagnetic transition tuned by an applied electric field can be realized at the p-type interface. This suggests an illuminating approach to multiferroic materials beyond conventional single-phase multiferroics and multi-phase multiferroics such as ferroelectric/ferromagnet heterostructures. The KTaO3/PbTiO3 interfaces may be promising in future multiferroic devices applications.