Enhancement of Curie temperature of gallium ferrite beyond room temperature by the formation of Ga0.8Fe1.2O3−Y3Fe5O12 composite

Abstract

Multiferroic materials with good magneto-electric coupling are of great interest due to their enormous applications in the field of spintronic devices. Magnetoelectric (ME) gallium ferrite is an interesting material due to its room temperature (RT) piezoelectricity and near RT ferrimagnetism along with significant ME coupling (10−11 s/m at 4.2 K). The work aims to increase the magnetic transition temperature (TC) of the material above RT so that the material can have strong ME coupling at room temperature and can be implemented for practical applications. Several earlier reports have shown the magnetic transition temperature of Ga2−xFexO3 increases with higher Fe contents. Hence, we chose to study the properties of Ga2−xFexO3 (GFO) only for x = 1.2. Y3Fe5O12 (YIG) is another material that is RT ferromagnet material with very high resistivity (∼1012 Ω cm). In this work, by forming a GFO-YIG composite with only a 10% concentration of YIG, the phase transition temperature is increased beyond room temperature from ∼289 K for GFO to ∼309 K for 0.9 GFO-0.1 YIG. The remnant magnetization is also enhanced from 0.211 emu/g to 2.82 emu/g reporting a magnetization of ∼8.2 emu/g at 30 kOe.