Electric field manipulation of magnetization in an insulating dilute ferromagnet through piezoelectromagnetic coupling

TL;DR

This study demonstrates electric field control of magnetization in an insulating dilute ferromagnet via piezoelectromagnetic coupling, revealing reversible and irreversible effects linked to magnetocrystalline anisotropy and hysteresis behavior.

Contribution

It provides experimental evidence of electric field manipulation of magnetization in GaMnN through piezoelectric effects, supported by theoretical modeling, and compares findings with similar phenomena in other dilute ferromagnetic semiconductors.

Findings

Magnetization changes are reversible and odd in electric field over wide magnetic ranges.

Non-linear, irreversible magnetoelectric effects occur in hysteresis regimes.

The results support theories of time-dependent perturbations affecting glassy magnetic states.

Abstract

We report magnetization changes generated by an electric field in ferromagnetic Ga$_{1-x}$Mn$_x$N grown by molecular beam epitaxy. Two classes of phenomena have been revealed. First, over a wide range of magnetic fields, the magnetoelectric signal is odd in the electric field and reversible. Employing a macroscopic spin model and atomistic Landau-Lifshitz-Gilbert theory with Langevin dynamics, we demonstrate that the magnetoelectric response results from the inverse piezoelectric effect that changes the trigonal single-ion magnetocrystalline anisotropy. Second, in the metastable regime of ferromagnetic hystereses, the magnetoelectric effect becomes non-linear and irreversible in response to a time-dependent electric field, which can reorient the magnetization direction. Interestingly, our observations are similar to those reported for another dilute ferromagnetic semiconductor Cr$_x$(Bi$_{1-y}$Sb$_y$)$_{1-x}$Te$_3$, in which magnetization was monitored as a function of the gate electric field. Those results constitute experimental support for theories describing the effects of time-dependent perturbation upon glasses far from thermal equilibrium in terms of an enhanced effective temperature.