Macrospin model of an assembly of magnetically coupled core-shell nanoparticles
Macrospin model of an assembly of magnetically coupled core-shell nanoparticles
复制标题
磁耦合核壳纳米颗粒组装体的宏观自旋模型
DOI：
10.1103/physrevb.106.104402
复制
发表时间：
2022
影响因子：
3.7
通讯作者：
Pereiro, Manuel
中科院分区：
文献类型：
--
作者：
Kons, Corisa;Srikanth, Hariharan;Phan, Manh-Huong;Arena, D. A.;Pereiro, Manuel
高度复杂的合成方法和实验技术允许精确测量纳米颗粒的磁性，这些磁性可以使用理论模型可靠地再现。在这里，我们用基于蒙特卡罗方法的理论方法研究了铁氧体纳米粒子的磁性。我们在宏磁模型中引入了三个复杂的阶段。首先，通过使用定制的哈密顿理论，我们研究了单个纳米粒子。在第二阶段，通过分别定义内部(核)和外部(壳)区域来考虑纳米颗粒的内部结构。在最后阶段，考虑了核壳纳米粒子的组装。已经估计了所有内部磁耦合，例如原子间和原子内交换作用或磁晶各向异性。此外，还计算了上述三种情况的磁滞回线，并与最近的实验测量结果进行了比较。在纳米粒子组装的情况下，磁滞回线以及零场冷和场冷曲线与实验数据符合得很好。目前的模型为理解纳米粒子的内部结构以及核壳铁氧体纳米粒子复杂的内部自旋相互作用提供了重要的工具。
Highly sophisticated synthesis methods and experimental techniques allow for precise measurements of magnetic properties of nanoparticles that can be reliably reproduced using theoretical models. Here, we investigate the magnetic properties of ferrite nanoparticles by using theoretical techniques based on Monte Carlo methods. We introduce three stages of sophistication in the macromagnetic model. First, by using tailor-made Hamiltonians we study single nanoparticles. In a second stage, the internal structure of the nanoparticle is taken into consideration by defining an internal (core) and external (shell) region, respectively. In the last stage, an assembly of core-shell nanoparticles is considered. All internal magnetic couplings such as interatomic and intra-atomic exchange interactions or magnetocrystalline anisotropies have been estimated. Moreover, the hysteresis loops of the aforementioned three cases have been calculated and compared with recent experimental measurements. In the case of the assembly of nanoparticles, the hysteresis loops together with the zero-field-cooling and field-cooling curves are shown to be in a very good agreement with the experimental data. The current model provides an important tool to understand the internal structure of the nanoparticles together with the complex internal spin interactions of the core-shell ferrite nanoparticles.
影响因子：
2.3
作者：
Mushtaq, Muhammad Waheed;Kanwal, Farah;Ullah, Zaka
通讯作者：
Ullah, Zaka