Magnetocaloric effect and nature of magnetic transition in low dimensional DyCu2
Magnetocaloric effect and nature of magnetic transition in low dimensional DyCu2
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DOI：
10.1016/j.jallcom.2016.05.042
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发表时间：
2016-06
期刊：
影响因子：
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通讯作者：
M. V. N. G. Kotnana;S. Jammalamadaka
中科院分区：
文献类型：
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作者：
M. V. N. G. Kotnana;S. Jammalamadaka
在这篇手稿中，我们提出了一种制备 DyCu2 小薄片的方法。除此之外，我们还报道了低维强各向异性 DyCu2 的磁热效应和磁转变性质。磁化测量在 5–100 K 的温度范围和最高 50 kOe 的最大磁场强度下进行。使用著名的麦克斯韦方程估算磁熵变 (ΔSM)，结果为 -4.31 J/kg-K。事实上，与块状 DyCu2 相比，ΔSMpeak 略微变宽，这种变宽可归因于总晶界体积的显着增加。由于这些小薄片在高于尼尔温度（TN）的温度下具有较大的 ΔSM 值，因此可以在较宽的温度范围内将它们用作磁性制冷剂材料。我们还绘制了 M2vs 的图。 H/M（称为阿罗特图），以发现磁转变的本质。 Arrott 图推断 M2vs 中确实存在非线性。 H/M 行为和此类非线性行为归因于系统中存在的随机各向异性或随机场。
In this manuscript, we propose a method to prepare small flakes of DyCu2. On top of that we also report on the magnetocaloric effect and nature of magnetic transition of a strongly anisotropic DyCu2in its low dimension. Magnetization measurements were carried out in the temperature range of 5–100 K and up to the maximum magnetic field strength of 50 kOe. Magnetic entropy change (ΔSM) is estimated using the well-known Maxwell’s equations and is found to be −4.31 J/kg-K. Indeed, the ΔSMpeak broadened marginally compared with its bulk DyCu2and such a broadening can be attributed to significant increase in the total grain boundary volume. As these small flakes consists larger ΔSMvalues at temperatures higher than the Nèel temperature (TN), one can use them as a magnetic refrigerant material in a broad temperature range. We also plotted the M2vs. H/M (which are called as the Arrott plots) in order to find the nature of magnetic transition. Arrott plots infer that indeed there exists nonlinearity in M2vs. H/M behavior and such nonlinear behavior is ascribed to the random anisotropy or a random field that is present in the system.