Synthesis and Magnetostrictive Properties of High-Pr Content  ${\rm Sm}_{1-x}{\rm Pr}_{x}{\rm Fe}_{1.9}$ Cubic Laves Alloys
Polycrystalline Sm<sub>1-</sub><i>x</i>Pr<i>x</i>Fe<sub>1.9</sub> (0.4 ≤ <i>x</i> ≤ 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<sub>2</sub>-type structure. The Curie temperature of the cubic Laves phase decreases linearly with the increase of <i>x</i>, which can be associated with the decreasing strength of 3<i>d</i>-4<i>f</i> coupling. With increasing <i>x</i> , the anisotropy of the alloys first decreases to a minimum at <i>x</i> = 0.6 and then increases. The magnetostriction of Sm<sub>1-</sub><i>x</i>Pr<i>x</i>Fe<sub>1.9</sub> changes signs from negative into a positive at <i>x</i> = 0.6 . The saturation magnetostriction increases with increasing <i>x</i>, while the sample with <i>x</i> = 0.9 shows a peak at low magnetic fields.
Direct experimental evidence for anisotropy compensation between Dy3+ and Pr3+ ions
Experimental evidence for the anisotropy compensation between Dy3+ and Pr3+ ions has been observed directly by performing x-ray diffraction on magnetic-field aligned powders and by evaluating the spin-reorientation temperature and the magnetostriction of Tb0.2Dy0.8-xPrx(Fe0.9B0.1)(1.93) alloys. The spin-reorientation temperature decreases with increasing the Pr content. The easy magnetization direction (EMD) at room temperature of the alloys rotates continuously in the (1 (1) over bar0) plane from for x=0.18 to for x=0.40, subjected to the anisotropy compensation between Dy3+ and Pr3+ ions. It is observed that the EMD of some of the alloys lies along nonmajor axes at room temperature. A maximum value of magnetostriction is achieved at x=0.22, which is also attributed to the anisotropy compensation. (c) 2006 American Institute of Physics.
Magnetoelastic properties of Sm1−xRxFe2 compounds
We have investigated the Mossbauer effect in SmFe2, Sm.9Dy.1Fe2 and Sm.7Ho.3Fe2. The easy axes of magnetization (EAM) as a function of temperature was determined. We find the Debye temperatures shift to lower values as the easy axis rotates toward 〈111〉. The Debye temperatures obtained here by observing the recoil‐free fraction (RFF) at the iron sites are higher than values obtained from the RFF at the rare‐earth sites or from ultrasonic data.