Abstract

In the present work, magnetocaloric properties of FM/AFM core/shell nanoparticles have been studied by using detailed Monte Carlo simulations. Thermal variation of isothermal magnetic entropy change of the core, shell, interface part and total nanoparticle with a spherical shape for various magnetic fields strengths have been examined. Also, dependence of the isothermal magnetic entropy change on the size and geometry of the nanoparticle has been analysed by considering the variation of the shape of the nanoparticle from oblate and prolate to a spherical one. Moreover, for the same shape evolution, cooling capacity (q) and maximum value of the entropy change have been presented as a function of applied magnetic field. Maximum value of the isothermal magnetic entropy change has been shown to take larger values as the applied magnetic field increases. Our numerical results suggest a linear relationship as \(q \sim bh_{max}\) between cooling capacity and magnetic field which is in accordance with the recent studies. A scaling behaviour as \(|\Delta S_{M}|_{max}\sim h_{max}^c\) has also been obtained between maximum value of the magnetic entropy change and magnetic field.

Graphic abstract

中文翻译：

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FM / AFM核/壳纳米粒子的磁热性质：蒙特卡洛模拟研究

摘要

在目前的工作中，已通过使用详细的蒙特卡洛模拟研究了FM / AFM核/壳纳米粒子的磁热性质。对于各种磁场强度，研究了核，壳，界面部分和球形总纳米粒子的等温磁熵变的热变化。而且，已经通过考虑纳米颗粒的形状从扁圆形和扁球形到球形球形的变化来分析等温磁熵变对纳米颗粒的尺寸和几何形状的依赖性。此外，对于相同形状的演变，冷却能力（q）和熵变化的最大值已被表示为施加磁场的函数。随着施加磁场的增加，等温磁熵变的最大值已显示取较大的值。我们的数值结果表明冷却能力和磁场之间的线性关系为\（q \ sim bh_ {max} \），这与最近的研究一致。还已经在磁熵变的最大值和磁场之间获得了标度行为，即\（| \ Delta S_ {M} | _ {max} \ sim h_ {max} ^ c \）。

图形摘要