Anisotropic magnetic entropy change in RFeO3 single crystals (R = Tb, Tm, or Y).
Anisotropic magnetic entropy change in RFeO3 single crystals (R = Tb, Tm, or Y).
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DOI：
10.1038/srep19775
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发表时间：
2016-01-25
影响因子：
4.6
通讯作者：
Cheng ZH
中科院分区：
文献类型：
--
作者：
Ke YJ;Zhang XQ;Ma Y;Cheng ZH
与传统的气体压缩/膨胀制冷相比，基于磁热效应的磁制冷具有能效高、环境友好等优点。在这里，我们通过磁晶各向异性较强的单晶的磁化矢量旋转，而不是仅仅通过有序-无序磁相变或磁结构转变，在RFeO_3(R- = ，Tb或TM)单晶中产生了大的磁致伸缩效应。由于Tb~(3+) 和Tm~(3+)离子中4f电子电荷分布的不同，TbFeO_3和Tm_3~(3+)单晶分别在9 K和17 = −K处获得了不同符号的旋转场熵，分别为17.42 J/kgK和-ΔSmr = −9.01 J/kgK，50 KE时，TbFeO_3和TmFe_3单晶从b轴到c轴的旋转场熵分别为17.42 J/kg K和17 J/kg K。大各向异性磁致伸缩效应的发现不仅加深了我们对磁致伸缩效应各向异性的认识，而且拓展了单晶材料在磁制冷方面的应用。
Compared with traditional gas-compression/expansion refrigeration, magnetic refrigeration based on magnetocaloric effect (MCE) exhibits the advantages of high energy efficiency and environment friendliness. Here, we created large MCE in RFeO3 (R = Tb or Tm) single crystals by the magnetization vector rotation of single crystal with strong magnetocrystalline anisotropy (MCA), rather than merely via the order-disorder magnetic phase transition or magnetic structural transition. Owing to the difference in charge distribution of 4f-electrons between Tb3+ and Tm3+ ions, the rotating field entropy with different signs, −ΔSMR = 17.42 J/kg K, and –ΔSMR = −9.01 J/kg K are achieved at 9 K and 17 K for TbFeO3 and TmFeO3 single crystals from b axis to c axis, at 50 kOe, respectively. The finding of the large anisotropic MCE not only advances our understanding of the anisotropy of MCE, but also extends the application for single crystals to magnetic refrigeration.