(北京工業(yè)大學(xué) 新型功能材料教育部重點(diǎn)實(shí)驗(yàn)室，北京 100124)
摘 要: 采用放電等離子燒結(jié)(SPS)技術(shù)制備致密塊狀納米晶SmCo5燒結(jié)磁體，研究磁體的結(jié)構(gòu)和磁性能。XRD結(jié)果表明：球磨粉末基本為非晶結(jié)構(gòu)，燒結(jié)磁體具有CaCu5結(jié)構(gòu)。TEM結(jié)果表明：磁體獲得晶體均勻分布的組織結(jié)構(gòu)，平均晶粒尺寸約為30 nm。電子選區(qū)衍射(SAED)分析表明：磁體主相為SmCO5相。室溫時磁體的矯頑力高達(dá)2.28 MA/m，而剩磁比Mr/Ms高達(dá)0.7，并通過剩磁曲線∆M—H及其變化趨勢，說明在納米晶之間存在強(qiáng)烈的晶間交換耦合作用。燒結(jié)磁體具有良好的高溫性能，773 K時其矯頑力為0.72 MA/m，矯頑力溫度系數(shù)β為−0.146%/K。
關(guān)鍵字: SmCo5；納米晶；放電等離子燒結(jié)；非晶粉末
（The Key Laboratory of Advanced Functional Materials, Ministry of Education,
Beijing University of Technology, Beijing 100124, China）
Abstract:The bulk nanocrystalline SmCo5 sintered magnet was prepared by spark plasma sintering technique (SPS). The structure and magnetic properties of the magnet were studied. XRD patterns show that the mill powder exhibits amorphous structure and the magnet exhibits CaCu5 structure. TEM observation indicates that the microstructure of the magnet is composed of SmCo5 single phase grains with an average grain size of 30 nm. The magnetic measurement shows that the coercivity of the magnet reaches as high as 2.28 MA/m. The high ratio Mr/Ms of 0.7 demonstrates the existence of strong intergrain exchange coupling among the nanograins. The magnet exhibits a good thermal stability with coercivity of 0.72 MA/m at 773 K, and the coercivity temperature coefficient β of −0.146%/K.
Key words: SmCo5; nanocrystalline; spark plasma sintering; amorphous powder
