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

Polycrystalline Sm_1-xPrxFe_1.9 (0.4 ≤ x ≤ 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 MgCu₂-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 Sm_1-xPrxFe_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.