Magnetostriction and spin reorientation in ferromagnetic Laves phase Pr(Ga _x Fe_1–x )_1.9 compounds*

Abstract

The magnetostriction, magnetization, and spin reorientation properties in Pr(Ga x Fe1 – 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(Tx Fe1 – 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.