We have studied magnetocaloric effect of kagome MgMnSn single crystal. The MgMnSn single crystal exhibits a typical transition of ferromagnetic (FM) to paramagnetic (PM). Maximum magnetic entropy change () and relative cooling power (RCP) for a field change of 0–50 kOe were calculated to be 3.05 J/kg K and 129 J/kg for //ab, 2.76 J/kg K and 115 J/kg for //c, respectively. Concurrently, around the phase transition temperature , the scaling approach for MgMnSn is used to study the magnetic entropy change . The outcome suggests that, in the presence of high field, the curves of can be effectively combined to form a single, universal curve that is unaffected by temperature or external fields. Nevertheless, under low field, curves diverge slightly below , indicating a first-order transition feature. According to the scaling analysis of curves, the phase transition of MgMnSn is forced into a second-order one under high field conditions, even if in the low field zone, it is a weak first-order type. Furthermore, it is discovered that the observed magnetocaloric effect (MCE) in kagome MgMnSn could not be satisfactorily explained by a basic theoretical model that simply took into consideration the magnetoelastic and magneto electron coupling.

中文翻译：

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kagome MgMn6Sn6 的磁热效应


我们研究了kagome MgMnSn单晶的磁热效应。 MgMnSn 单晶表现出典型的铁磁 (FM) 到顺磁 (PM) 的转变。对于 0-50 kOe 的磁场变化，计算得出的最大磁熵变 () 和相对冷却功率 (RCP) 为 //ab 的 3.05 J/kg K 和 129 J/kg， //ab 的最大磁熵变 () 和相对冷却功率 (RCP)，2.76 J/kg K 和 115 J/ kg 分别为 //c。同时，在相变温度附近，采用MgMnSn的标度方法来研究磁熵变。结果表明，在存在高场的情况下，可以有效地将 的曲​​线组合起来，形成一条不受温度或外部场影响的单一通用曲线。然而，在低场下，曲线在 下方略微发散，表明存在一阶过渡特征。根据曲线标度分析，MgMnSn的相变在高场条件下被强制为二阶相变，即使在低场区也是弱一阶型。此外，我们还发现，kagome MgMnSn 中观察到的磁热效应（MCE）无法通过简单考虑磁弹性和磁电子耦合的基本理论模型得到令人满意的解释。