铜含量对Sm(CoCuFeZr)_8磁性能的影响

在氩气保护下用单辊熔体快淬法制备了不同Cu含量的Sm(Co0.74CuxFe0.1Zr0.04)8(x(Cu)=0,x(Cu)=0.1％,x(Cu)=0.12％,x(Cu)=0.16％)快淬带。将快淬带进行不同温度(400、500、600、700℃)回火处理。用振动样品磁强计、差热分析仪和X-射线衍射仪分别测定了样品的磁性、相变行为和相结构。研究表明,x(Cu)=0.12％的Sm(CoCuFeZr)8合金矫顽力最高,X-射线结构分析显示其对应的主要相为Cu7Tb型1:7相结构。x(Cu)=0.12％样品的快淬态与500℃回火态的衍射峰比较,其快淬态衍射峰稍有宽化,表明500℃回火后晶粒稍有长大。高温M-T磁性分析和差热分析DTA分析显不在380℃和801℃有磁相变,380℃有1:5相亚温分解,801℃是1:7相的居里点。分析表明500℃回火后矫顽力的提高是由于Cu向晶界的偏聚造成钉扎作用增强引起的。

Effect of Cu contents on magnetic properties of the Sm(Co0.74CuxFe0.1Zr0.04)8

The Sm(Co0.74CuxFe0.1Zr0.04)8(x=0,0.1, 0. 12,0. 16)ribbons with different Cu contents have been prepared by single roller melt spinning in Ar gas. The prepared ribbons are annealed at different temperature(400,500,600,700℃) for 30 min. Magnetic measurements show that the maximal coercivity can be obtained in the x = 0. 12 samples annealed at 500℃. X-ray diffraction analyses show that the as - quenched and annealed ribbons of x = 0. 12 are TbCu7 - type structure. But the diffraction peak of as quenched samples is slightly broad, which means that the grain size of samples has grown up after annealing. M-T magnetic and DTA analysis reveal that magnetic phase transformation may occur at 380℃ and 800℃. The transformation at 380℃ respon des to the spinodal decomposition and the 800 ℃ corresponds to the Curie point of phase 1: 7. The strong pinning of the walls of the network of grain boundaries in which the Cu is gathered results in the improvement of the coercivity of ribbons.