Fe-Ga-Tb alloys for soft magnetic applications

Abstract The current paper deals with the influence of Tb doping on magnetic and magnetostrictive properties of Fe-19Ga-xTb (x up to 0.37 at.%) and Fe-27.4Ga-xTb (x up to 0.5 at.%) alloys at room temperature by vibrating sample magnetometry and strain gauge methods. The magnetocrystalline anisotropy constant and the magnetic permeability are improved in Fe19Ga-xTb alloys upon Tb addition. A three-time enhancement of the magnetostriction up to ≈ 235 ppm in Fe-19Ga-0.37Tb alloys is observed. Alloying of Fe-27.4Ga with 0.3 at.%Tb increases the magnetization, permeability, and magnetostriction, and decreases the coercivity, remanent magnetization, and hysteresis losses. Beyond this Tb content, a considerable amount of the phase enriched in Ga and Tb precipitates, which opposes magnetic domain wall motions and declines the magnetic properties. An improvement of the magnetic properties in Fe-Ga-Tb alloys might be correlated to the magnetocrystalline anisotropy and the localized strain induced by Tb. The present work demonstrates that the full potential of Fe-Ga-Tb alloys is yet to be explored for engineering soft magnetic applications.