Electric field control of magnetic states in isolated and dipole-coupled FeGa nanomagnets delineated on a PMN-PT substrate

TL;DR

This study demonstrates a non-volatile magneto-electric effect in FeGa nanomagnets on a piezoelectric substrate, enabling electric control of magnetic states with potential applications in energy-efficient logic and memory devices.

Contribution

It reveals a novel non-volatile magneto-electric effect in isolated and dipole-coupled FeGa nanomagnets on a PMN-PT substrate, showing electric field-induced magnetization rotation.

Findings

Electric field induces non-volatile magnetization rotation in nanomagnets.

Dipole coupling enhances magnetization rotation beyond 90 degrees.

Potential for ultra-energy-efficient magnetic logic and memory devices.

Abstract

We report observation of a "non-volatile" converse magneto-electric effect in elliptical FeGa nanomagnets delineated on a piezoelectric PMN-PT substrate. The nanomagnets are initially magnetized with a magnetic field directed along their nominal major axis and subsequent application of an electric field across the substrate generates strain in the substrate, which is partially transferred to the nanomagnets and rotates the magnetizations of some of them to metastable orientations. There they remain after the field is removed, resulting in "non-volatility". In isolated nanomagnets, the angular separation between the initial and final magnetization directions is < 90 deg, but in a dipole-coupled pair consisting of one "hard" and one "soft" nanomagnet, the soft nanomagnet's magnetization is rotated by > 90 deg from the initial orientation because of the dipole influence of the hard nanomagnet. These effects can be utilized for ultra-energy-efficient logic and memory devices.