中文摘要：

采用放电等离子烧结技术制备了致密纳米晶SmCo6.6Nb0.4烧结磁体,研究了磁体的结构和磁性能,结果表明,烧结磁体具有TbCu7结构,说明通过SPS过程可以获得稳定的1：7相;磁体由平均晶粒尺寸约为30 nm的1：7相构成,磁体的室温矫顽力高达2.8 T,而剩磁比高达0.74,说明在纳米晶之间存在强烈的晶间交换耦合作用.烧结磁体具有良好的高温性能,773 K时的矫顽力为0.48 T,矫顽力温度系数β为-0.169%/K.

英文摘要：

Bulk nanocrystalline SmCo6.6Nb0.4 sintered magnet was prepared by spark plasma sintering technique （SPS）. Structure and magnetic properties of magnet was studied. XRD patterns show that the magnet exhibits TbCu7 structure, indicating a stable 1：7 phase was obtained after SPS process. TEM observation indicates that the microstructure of the magnet is composed of SmCo6.6Nb0.4 single-phase grains with an average grain size of 30 nm. Magnetic measurement shows that the coercivity of the magnet reaches as high as 2.8 T; the high ratio Mr/Ms of 0.74 demonstrates the existence of strong intergrain exchange coupling among the nanograins. The magnet exhibits a good thermal stability with the coercivity of 0.48 T at 773 K, and the coercivity temperature coefficient β of -0.169%/K.