摘要
研究了La0.6Pr0.4Fe11.4Si1.6B0.2合金及其氢化物La0.6Pr0.4Fe11.4Si1.6B0.2Hy的制备工艺与磁热效应。室温XRD分析与SEM成分分析表明La0.6Pr0.4Fe11.4Si1.6B0.2合金主相为NaZn13型立方结构(空间群为Fm-3c),存在富La相(空间群为P4/nmm)与富Fe相。氢化物La0.6Pr0.4Fe11.4Si1.6B0.2Hy的晶格常数a由合金的1.2295 nm增大到1.2491 nm。DSC测定氢化物的氢含量y约为1.7。磁性测量结果表明:氢化物La0.6Pr0.4Fe11.4Si1.6B0.2Hy的居里温度TC由合金的198 K增至325 K,提高了127 K。在0～1.5 T外磁场下合金与氢化物最大磁熵变-ΔSmMax均为9.1 J.kg-.1K-1。氢化物La0.6Pr0.4Fe11.4Si1.6B0.2Hy在室温下搁置190 d后物相与磁热效应基本保持不变。
The preparation and magnetocaloric effects of the La0.6Pr0.4Fen.4Sil.6B0.2 alloy and its hydride La0.6Pr0.4Fell.4Sil.sB0.2Hy were investigated. The X-ray diffraction（XRD） and scanning electron microscopy（SEM） results showed that the microstructures of the La0.6Pr0.4Fell.4Sil.sB0.2 alloy were composed of the NaZn13-type phase with space group of Fm-3c, La-rich phase and Fe-rich phase. The absorbing hydrogen content was determined by differential scanning calorimetry （ DSC ） method to be about y = 1.7. The lattice constant increased from 1. 2295 to 1. 2491 nm, indicating lattice expansion. The magnetic measurement results showed that the Curie temperature of hydride La0.6Pr0.4Fell.4Sil.6B0.2Hy increased from 198 to 325 K and this hydride aged at room temperature for 190 d maintained a large magnetocaloric effect, with a maximum magnetic entropy change of 9.1 J.kg-l.K-t in a magnetic field of 1.5 T.
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2013年第4期543-548,共6页
Chinese Journal of Rare Metals
基金
国家科技部863计划项目(2011AA03A404)资助
国家国际科技合作项目(2011DFA53230)资助
国家自然科学基金项目(50961010
51161016)资助
关键词
NaZn13型合金
吸氢
居里温度
磁熵变
NaZn13-type alloy
hydride
Cuire temperature
magnetic entropy change
