Shen Chenhai, Li Xueping, Wang Tianxing, Wang Guangtao, Xia Congxin
School of Physics, Henan Normal University, Xinxiang 453007, China.
Nanoscale. 2023 Jul 27;15(29):12340-12347. doi: 10.1039/d3nr01434g.
Excellent magnetic properties at room temperature are crucial for the application of ferromagnets in spintronic and topological quantum devices. Using first-principles calculations and atomistic spin model simulations, we investigate the temperature-dependent magnetic properties of the Janus monolayer FeXY (X, Y = I, Br, Cl; X ≠ Y), as well as the effects of different magnetic interactions within the next-nearest-neighbor shell on the Curie temperature (). A large isotropic exchange interaction between one Fe atom and its next-nearest-neighbor counterparts can significantly increase the , while an antisymmetric exchange interaction decreases it. More importantly, we employ the temperature rescaling method, which can obtain temperature-dependent magnetic properties quantitatively consistent with experimental values, and find that the effective uniaxial anisotropy constant and coercive field decrease with increasing temperature. Moreover, at room temperature, FeIY is a rectangular-loop magnetic material with a giant coercive field up to ∼8 T, demonstrating its potential for application in room-temperature memory devices. Our findings can advance the application of these Janus monolayers in room-temperature spintronic devices and through heat-assisted techniques.
室温下优异的磁性对于铁磁体在自旋电子学和拓扑量子器件中的应用至关重要。我们使用第一性原理计算和原子自旋模型模拟，研究了Janus单层FeXY（X、Y = I、Br、Cl；X ≠ Y）的温度依赖性磁性，以及次近邻壳层内不同磁相互作用对居里温度（）的影响。一个Fe原子与其次近邻原子之间的大的各向同性交换相互作用可显著提高居里温度，而反对称交换相互作用则会降低居里温度。更重要的是，我们采用温度重标度方法，该方法能够获得与实验值在定量上一致的温度依赖性磁性，并发现有效单轴各向异性常数和矫顽场随温度升高而降低。此外，在室温下，FeIY是一种具有高达约8 T的巨大矫顽场的矩形磁滞回线磁性材料，展示了其在室温存储器件中的应用潜力。我们的研究结果可推动这些Janus单层在室温自旋电子器件中的应用，并通过热辅助技术实现应用。
