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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 process and magnetocaloric effect of La0.6Pr0.4Fe11.4Si1.6B0.2 alloy and its hydride La0.6Pr0.4Fe11.4Si1.6B0.2Hy were studied. The results of XRD and SEM at room temperature show that the main phase of La0.6Pr0.4Fe11.4Si1.6B0.2 alloy is NaZn13 type cubic structure (space group Fm-3c), La-rich phase (P4 / nmm space group) Fe phase. Hydride La0.6Pr0.4Fe11.4Si1.6B0.2Hy lattice constant a from 1.2295 nm alloy increased to 1.2491 nm. The hydrogen content y of the hydride measured by DSC is about 1.7. The magnetic measurements show that the Curie temperature TC of La0.6Pr0.4Fe11.4Si1.6B0.2Hy hydride increased from 198 K to 325 K and increased 127 K. The maximum magnetic entropy change of alloys and hydrides -ΔSmMax in the magnetic field from 0 to 1.5 T are 9.1 J.kg-.1K-1. Hydride La0.6Pr0.4Fe11.4Si1.6B0.2Hy remained at room temperature 190 days after the phase and magnetocaloric effect remained unchanged.