Magnetocaloric properties of compounds with first order phase transition: Hysteresis effect
Magnetocaloric properties of compounds with first order phase transition: Hysteresis effect
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DOI：
10.1016/j.jallcom.2011.03.020
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发表时间：
2011-06
影响因子：
6.2
通讯作者：
R. P. Santana;N. Oliveira;P. Ranke
中科院分区：
文献类型：
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作者：
R. P. Santana;N. Oliveira;P. Ranke
本文从理论上讨论了一级相变化合物的磁热效应，并考虑了磁滞效应。为此，我们使用的局部磁矩，包括磁弹性相互作用的微观模型。计算结果表明，在具有大磁弹性耦合的一级相变化合物中，磁热势Δ Siso和Δ Tad依赖于温度变化的方向.此外，我们的计算还表明，只有在磁滞可以忽略的情况下，一级相变附近的磁热势Δ Siso才能通过麦克斯韦关系由磁化强度数据计算出来.
In this paper we theoretically discuss the magnetocaloric effect in compounds undergoing first order phase transition, taking into account the hysteresis effect. For this purpose we use a microscopical model of localized magnetic moments including the magnetoelastic interaction. Our calculations show that in compounds undergoing first order transition with large magnetoelastic coupling, the magnetocaloric potentialsΔSisoandΔTaddepend on the direction of the temperature variation. Moreover, our calculations also show that the magnetocaloric potentialΔSisoaround a first order phase transition can be calculated using magnetization data via the Maxwell relation only if the hysteresis is negligible.