Effect of thermal oxidation on the structural and magnetic properties of TbFe2 alloys

Abstract

Because of its highest magnetostriction at room temperature, TbFe2 is one of the most promising materials for magnetostrictive applications. However, oxidation-induced deterioration in its magnetic properties limits its usage at higher temperature (T) and/or longer time (t). In this regard, a systematic study is performed here to understand the effect of oxide-film overgrowth (by varying T and t) on the microstructure and magnetic properties of TbFe2. The characteristic parameters of magnetic properties, such as coercivity (Hc) and remanent magnetization (Mr), are found to decrease with increasing T and/or t. Moreover, a strong correlation between the oxidation-induced microstructure and magnetic properties is observed. Understanding developed in this study will help in choosing optimum working conditions (i.e., T and/or t) for TbFe2 to avoid significant deterioration in the magnetic properties.