Negative magnetocaloric effect at the antiferromagnetic to ferromagnetic transition of Mn3GaC
Negative magnetocaloric effect at the antiferromagnetic to ferromagnetic transition of Mn3GaC
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DOI：
10.1063/1.1587265
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发表时间：
2003-07
影响因子：
3.2
通讯作者：
T. Tohei;H. Wada;T. Kanomata
中科院分区：
文献类型：
--
作者：
T. Tohei;H. Wada;T. Kanomata
研究了Mn 3GaC的磁热效应，该磁热效应在165 K时表现出反铁磁到铁磁的转变。在该化合物中，在转变处获得的磁热效应与普通铁磁系统相反，即负磁热效应。结果表明，在2 T的磁场下，磁熵变ΔSmag为15 J/kg K。场变化2 T时，绝热温度变化ΔTad达到5.4 K。在较高的磁场下，ΔSmag和ΔTad在较宽的温度范围内保持较大的值，表现出梯形形状的特征温度依赖性。这些特点是由于一个尖锐的一级转变保留在高磁场以及小磁晶各向异性。
The magnetocaloric effect of Mn3GaC, which shows an antiferromagnetic to ferromagnetic transition at 165 K has been investigated. In this compound, magnetocaloric effect obtained at the transition is opposite to that of ordinary ferromagnetic systems, namely, negative magnetocaloric effect. It was found that a large magnetic entropy change, ΔSmag, of 15 J/kg K is obtained under an applied field of 2 T. The adiabatic temperature change, ΔTad, reaches 5.4 K in a field change of 2 T. At higher magnetic fields, both ΔSmag and ΔTad retain a large value over wide temperature range, exhibiting characteristic temperature dependence of a trapezoidal shape. These features are attributed to a sharp first-order transition retained in high magnetic fields as well as small magnetocrystalline anisotropy.