SPIN REORIENTATION PHENOMENA IN SUBSTITUTED Pr2 (Co, Fe)17 INTERMETALLICS

The magnetic anisotropy phase diagrams of Pr2Co17-,Fen and Pr2Co17-,Fez-,Ty (T=Mn, Zr, Ti, Hf) compounds have been determined. Two spin reorientation temperatures, TSr1 and Tsr2, have been observed. Near the Ts,l or Ts,2 boundary the anisotropy is conical; between the two spin reorientation temperatures they exhibit uniaxial anisotropy and beyond these limits they are planar. Introduction --0-y co 2 17-x Fex The Pr2 (Col-,Fe,),, intermetallics exhibit inter-"Pr,Co,,-, Fex esting magnetic properties. Their anisotropies are sensitive to the composition x. For example, at room temperature, the easy direction of magnetization is uniax, i d for 0.2 < z < 0.6, but it changes from axial to basal 2 plane for low x and high a: 11-31. The spin reorientation temperature, T,,, of Pr2 (Coo.sFeo.a),, was measured by Sousa et al. [4] using the electrical resistivity sin400 Planar gularity method. The partial magnetic phase diagram of this system was investigated by Mori et al. [5] using the magnetostriction method. But the nature of the spin reorientation in this system has not been de4 8 12 16 X termined unambiguously due to the limited number of compositions and/or the temperature range employed Fig. 1. Magnetic phase diagram of Pr2Col.r-,Fez and by the above investigators. Y2Col7-,Fez. In this paper, we report the results of the variation of spin reorientation temperature in the Pr2Col.r-,FeX and Prl.8Smo.2Co~7-,Fe, systems. The effect of substitution of Mn, Zr, Ti and Hf on the spin reorientation temperature has also been investigated.