Effect of Pr on the Structure and Magnetic Properties of CoPt Alloys

摘要:

对PrxCo50-xPt50 (x = 0, 0.2, 0.4, 0.6, 0.8, 1.0) 合金的显微结构和磁性能进行了研究。X射线衍射结果表明：经 1000 ℃均匀化后合金为单一的面心立方相（fcc），而经 675 ~ 750 ℃退火后合金由硬磁相（面心四方结构，fct）和软磁相组成。随着Pr含量增加，fct 的（111）衍射峰向高角度偏移，并且 c/a 增大导致有序度 S 减小。合金Pr0.4Co49.6Pt50 经 675 °C 退火 60 min 后，矫顽力和剩磁比达到最大值。PrxCo50-xPt50 (x = 0, 0.2, 0.4, 0.6, 0.8, 1.0) 经 675 °C 退火 60 min 的样品，矫顽力随着Pr含量的增加而单调减小，但剩磁比先增大后减小。

Abstract:

The effects of Pr on the microstructure and magnetic properties of PrxCo50-xPt50 alloys (x = 0, 0.2, 0.4, 0.6, 0.8, 1.0) were investigated. The XRD results indicate that all the alloys homogenized at 1000 °C contain only a single A1 (fcc) phase, while the alloys annealed at 675-750 °C consist of a hard-magnetic face-centered-tetragonal (fct) phase and a magnetically soft fcc phase. The (111) reflection belonging to the fct phase shifts to a higher angle and the c/a ratio increases as the Pr content increases, which leads to a decrease in the degree of ordering, S. Maximum values for the coercivity Hc and the remanence ratio mr are achieved in Pr0.4Co49.6Pt50 alloys annealed at 675 °C for 60 min. For the series of PrxCo50-xPt50 alloys annealed at 675 °C for 60 min, Hc decreases monotonically with increasing of Pr concentration, but mr is first enhanced and then weakened, showing a maximum value of 0.82 at x = 0.4 to 0.6.