采用铜模吸铸法制备了(Nd0.7Pr0.3)60-xFe30Al10Dyx(x=0,1,2)大块非晶合金,利用振动样品磁强计(VSM)研究了该合金室温下的磁性能、不可逆磁化率、铁磁交换耦合作用及不同温度下矫顽力与温度之间的关系。结果表明,这几种合金室温下均呈现出较好的硬磁性,随着 Dy 元素的添加,合金的饱和磁化强度和剩余磁化强度略有变化,内禀矫顽力明显增大。合金中均存在着明显的铁磁交换耦合作用,同时,矫顽力与温度之间的关系符合 Gaunt的强钉扎模型,合金的硬磁性可能是这两种机制的共同作用产生的。
Bulk amorphous (Nd0.7Pr0.3)60-xFe30Al10Dyx(x=0,1,2)alloys of 2 mm in diameter were prepared by argon arc melting and suction casting the molten alloy into a copper mould.The magnetic properties of the alloys,including major hysterisis loops,the field dependence of the irreversible susceptibility,exchange cou-pling curves (δM-H plot)and the temperature dependence of the coercivity,were investigated by vibrating sample magnetometer (VSM).The results indicated that each alloy sample exhibited hard magnetic behavior. With increasing Dy content,the residual magnetisation and saturation magnetisation changed slightly while the coercivity was enhanced apparently.The exchange coupling interactions in these alloys were confirmed by theδM-H plots.The temperature dependence of the coercivity was well explained by Gaunt’s strong pinning model of domain walls.The hard magnetic behavior of bulk amorphous (Nd0.7Pr0.3)60-xFe30Al10Dyx(x=0,1,2)al-loys may be attrituted to the effect of exchange coupling interaction among clusters and the strong domain wall pinning mechanism.