Bismuth iron garnet Bi3Fe5O12: a room temperature magnetoelectric material

TL;DR

This paper demonstrates room temperature linear magnetoelectric coupling in bismuth iron garnet (BIG), highlighting its potential for spintronic and magnonic applications due to its combined magnetic, optical, and electrical properties.

Contribution

It provides the first clear observation of linear ME coupling above 300 K in BIG, linking it to bismuth ions and magnetic domain structures, advancing material understanding.

Findings

Linear ME coupling observed above 300 K in BIG.

Coupling strength comparable to Cr2O3.

Link between bismuth ions, spin orbit coupling, and magnetic inhomogeneities.

Abstract

The possibility to control the magnetic properties of a material with an electric field at room temperature is highly desirable for modern applications. Moreover, a coupling between magnetic and electric orders within a single material presenting a wide range of exceptional physical properties, such as bismuth iron garnet (BIG), may lead to great advances in the field of spintronic applications. In particular, the combination of the magnetoelectric (ME) coupling with the low damping of spin waves in BIG can allow the control and manipulation of spin waves by an electric field in magnonic devices. Here we report the unambiguous observation of linear magnetoelectric coupling above 300 K in BIG using ferromagnetic resonance technique with electric field modulation. The measured coupling value is comparable with that observed for prototypal magnetoelectric Cr2O3. On the basis of our experimental results, the strength of this linear ME coupling is directly linked to the presence of bismuth ions inducing strong spin orbit coupling and to the appearance of local magnetic inhomogeneities related to the magnetic domain structure. The unprecedented combination of magnetic, optical and magnetoelectrical properties in BIG is expected to trigger significant interest for technological applications as well as for theoretical studies.