Tunable magnetism in ferroelectric {\alpha}-In2Se3 by hole-doping

TL;DR

This study predicts that hole-doping in 2D ferroelectric { extalpha}-In2Se3 induces stable ferromagnetism with high Curie temperature, tunable magnetic properties, and strong magnetoelectric coupling, advancing 2D multiferroic materials for device applications.

Contribution

First-principles calculations reveal hole-doping induces robust ferromagnetism and magnetoelectric coupling in 2D { extalpha}-In2Se3, a novel approach for designing 2D multiferroics.

Findings

Hole-doping induces ferromagnetism in 2D { extalpha}-In2Se3.

Curie temperature can exceed room temperature.

Magnetic properties are tunable by doping, strain, and layer number.

Abstract

Two-dimensional (2D) multiferroics attract intensive investigations because of underlying science and their potential applications. Although many 2D systems have been observed/predicted to be ferroelectric or ferromagnetic, 2D materials with both ferroic properties are still scarce. By using first-principles calculations, we predict that hole-doping can induce robust ferromagnetism in 2D ferroelectric {\alpha}-In2Se3 due to its unique flat band structure, and the Curie temperature (TC) can be much higher than room temperature. Moreover, the doping concentration, strain, and number of layers can effectively modulate the magnetic moment and the TC of the material. Interestingly, strong magnetoelectric coupling is found at the surface of hole doped multilayer {\alpha}-In2Se3, which allows non-volatile electric control of magnetization. Our work provides a feasible approach for designing/searching 2D multiferroics with great potential in future device applications, such as memory devices and sensors.