Structure and Properties of Magnetoelectric Gallium Ferrite: A Brief Review

Abstract

Here, we review the advances in understanding the structure and properties of magnetoelectric gallium ferrite (GaFeO 3 or GFO). Special significance of GFO lies in its compositional tunability over a large range of Ga:Fe ratio without forming a second phase which also renders prospective room temperature magnetoelectricity in the material. Detailed structural studies show noncentrosymmetric orthorhombic Pc2 1 n symmetry without any structural phase transition between 4 K and 700 K. The material shows a ferrimagnetic behavior driven by cation site disorder, corroborated both experimentally as well as theoretically, with transition temperature dependent upon Ga:Fe ratio. GFO exhibits magnetostructural and magnetoelectric coupling indicating coupling among the structural, magnetic and electrical degrees of freedom which could possibly be utilized to strain engineer electrical and magnetic properties in the thin film structures. However, the biggest challenge remains to reduce the leakage in the material in both thin film and bulk form which hinders its potential as a device material.

Incorporation of cobalt ions into magnetoelectric gallium ferrite epitaxial films: tuning of conductivity and magnetization

“…These anomalies have been attributed to a spin-phonon coupling. [32][33][34] Fig. 2 Reciprocal space mapping (RSM) of {062} reflection in the (a) GFO and (b) GFO:Co 1.2% thin films.…”

Spin Current Transport in Hybrid Pt/Multifunctional Magnetoelectric Ga0.6Fe1.4O3 Bilayers

“…Here, we propose the use of another oxide, the multifunctional magnetoelectric gallium ferrite Ga 2– x Fe x O 3 (GFO x , 0.8 ≤ x ≤ 1.4), − with a view to use its magnetoelectric character in the future for an electric field control of the spin current generation from NM/FM heterostructures. Ga 2– x Fe x O 3 crystallizes in the polar orthorhombic Pna 2 1 (equivalently Pc 2 1 n ) space group (S.G.#33), , different from the usual perovskite structure adopted by most of the other magnetoelectric compounds, with a = 0.5086(2) nm, b = 0.8765(2) nm, and c = 0.9422(2) nm for x = 1.4 .…”

Co Incorporation on Structure, Conductivity and Magnetism of GaFeO3

“…As a member of multiferroic family, GaFeO 3 (GFO) is one of the most promising materials because of its good piezoelectricity at room temperature [6][7][8] , near roomtemperature ferrimagnetism [9][10] , and pronounced lowtemperature ME effects [11] . Although GFO owns such attractive features, its large electrical leakage and lower magnetic transition temperature limit its application as storage devices.…”