Magnetostriction and spin reorientation in ferromagnetic Laves phase Pr(GaxFe1–x)1.9 compounds.

The magnetostriction, magnetization, and spin reorientation properties in Pr(Ga_xFe_{1 – x})_1.9 alloys have been investigated by high-precision x-ray diffraction (XRD) step scanning, magnetization, and Mössbauer spectra measurements. Ga substitution reduces the magnetostriction (λ_||) with magnetic field H ≥ 8 kOe (1 Oe = 1.33322 × 10² Pa), but it also increases the λ_|| value when H ≤ 8 kOe at 5 K. Spin-reorientations (SR) are observed in all the alloys investigated, as determined by the step scanned XRD, Mössbauer spectra, and the abnormal temperature dependence of magnetization. An increase of the spin reorientation temperature (T_SR) due to Ga substitution is found in the phase diagram, which is different from the decrease one in many R(T_xFe_{1 – x})_1.9 (T = Co, Al, Mn) alloys. The present work provides a method to control the easy magnetization direction (EMD) or T_SR for developing an anisotropic compensation system. [ABSTRACT FROM AUTHOR]