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-
x
Pr
x
Fe
_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 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 3
d
-4
f
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-
x
Pr
x
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.