Specific heat and entropy change at the first order phase transition of La(Fe-Mn-Si)13-H compounds
Specific heat and entropy change at the first order phase transition of La(Fe-Mn-Si)13-H compounds
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DOI：
10.1063/1.4928086
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发表时间：
2015-08-07
影响因子：
3.2
通讯作者：
Cohen, Lesley F.
中科院分区：
文献类型：
--
作者：
Basso, Vittorio;Kuepferling, Michaela;Cohen, Lesley F.
本文介绍了用Mn取代Fe来微调转变温度的氢化La（Fe-Mn-Si）（13）-H的磁热性质的实验研究结果。用直接Peltier量热法测量了一系列化合物在磁场下的比热c（p）（H，T）和磁场诱导的等温熵变Δ s（H，T）。结果表明，Mn从0.06增加到0.46，使相变温度从339 K降低到270 K，而由1.51场引起的总熵变从18.7J kg（-1）K（-1）降低到10.2J kg（-1）K（-1），热滞也从1.5K降低到零。在本文中，我们解释的磁相变从第一个到第二个顺序随着Mn含量的增加，我们讨论的结果的价值磁冷却应用。(C)2015 AIP Publishing LLC.
In this paper, we present the results of an experimental investigation on the magnetocaloric properties of hydrogenated La(Fe-Mn-Si)(13)-H with Mn substituting Fe to finely tune the transition temperature. We measured the specific heat under magnetic field c(p)(H,T) and the magnetic field induced isothermal entropy change Delta s(H, T) of a series of compounds by direct Peltier calorimetry. Results show that increasing Mn from 0.06 to 0.46 reduces the transition temperature from 339 K to 270K whilst the total entropy change due to a 1.51 field is depressed from 18.7 J kg(-1)K(-1) to 10.2 J kg(-1)K(-1) and the thermal hysteresis similarly is reduced from 1.5 K to zero. In the paper, we interpret the results in terms of a magnetic phase transition changing from the first to the second order with increasing Mn content, and we discuss the value of the results for magnetic cooling applications. (C) 2015 AIP Publishing LLC.