Synthesis and Magnetostrictive Properties of High-Pr Content ${rm Sm}_{1-x}{rm Pr}_{x}{rm Fe}_{1.9}$ Cubic Laves Alloys

摘要

Polycrystalline ${rm Sm}_{1-x}{rm Pr}_{x}{rm Fe}_{1.9}$ $(0.4leq xleq 1.0)$ magnetostrictive alloys were synthesized by arc-melting and subsequent high-pressure annealing. Measurements of x-ray diffraction, magnetization, and magnetostriction were performed on the alloys. Due to the effects of high-pressure, the alloys are stabilized in cubic Laves phase with ${rm MgCu}_{2}$-type structure. The Curie temperature of the cubic Laves phase decreases linearly with the increase of $x$, which can be associated with the decreasing strength of $3d-4f$ coupling. With increasing $x$ , the anisotropy of the alloys first decreases to a minimum at $x=0.6$ and then increases. The magnetostriction of ${rm Sm}_{1-x}{rm Pr}_{x}{rm Fe}_{1.9}$ changes signs from negative into a positive at $x=0.6$ . The saturation magnetostriction increases with increasing $x$, while the sample with $x=0.9$ shows a peak at low magnetic fields.