Structural, magnetic and magnetostrictive properties of Laves-phase compounds TbxHo0.9−xNd0.1Fe1.93 (0 ≤ x ≤ 0.40)

Abstract

The structural, magnetic and magnetostrictive properties of TbxHo0.9−xNd0.1Fe1.93 (0 ≤ x ≤ 0.40) alloys have been investigated by means of X-ray diffraction (XRD), a vibrating sample magnetometer and a standard strain technique. Single Laves phase (Tb,Ho,Nd)Fe2 compounds with a cubic MgCu2-type structure have been synthesized at equilibrium conditions with ambient pressure. The lattice parameter of the Laves phase increases linearly with increasing Tb content and obeys the linear Vegard's law. The easy magnetization direction (EMD) at room temperature rotates continuously from <100> for x = 0.10 to <111> for x = 0.25 through an intermediate direction <110> around x = 0.15, subjected to the anisotropy compensation between Tb3+ and Ho3+ ions. The splitting of (440) XRD peak accompanied by the spontaneous magnetostriction-induced rhombohedral distortion is observed for the compounds of x ≥ 0.2, and the spontaneous magnetostriction coefficient λ111 is found to increase with increasing Tb content. The analysis of XRD, EMD, magnetization and magnetostriction shows that the pseudobinary system TbxHo0.9−xNd0.1Fe1.93 is an anisotropy compensation system and the compensation point is realized around x = 0.25. The Nd-containing Tb0.25Ho0.65Nd0.1Fe1.93 Laves-phase compound has good magnetostrictive properties, that is, a large saturation magnetostriction (λS∼585 ppm) and a low magnetocrystalline anisotropy at room temperature, which may make it technological interest for magnetostriction applications.