Bai Yihang, Shi Rui, Wu Yaxuan, Wang Bing, Zhang Xiuyun
Institute for Computational Materials Science, School of Physics and Electronics, Henan University, Kaifeng 475004, People's Republic of China.
Patent Examination Cooperation (Henan) Center of the Patent Office, China National Intellectual Property Administration, Zhengzhou 450000, People's Republic of China.
J Phys Condens Matter. 2022 Jul 18;34(38). doi: 10.1088/1361-648X/ac7f16.
Two-dimensional (2D) ferromagnetic semiconductor (FMS) provides the ideal platform for the development of quantum information technology in nanoscale devices. However, most of them suffer from low Curie temperature and small magnetic anisotropic energy (MAE), severely limiting their practical application. In this work, by using first-principles calculations, we predicted two stable 2D materials, namely, CrSiTeand CrGeTemonolayers. Interestingly, both of them are intrinsic direct band gap FMSs (∼1 eV) with a large magnetization (8f.u.) and sizable MAE (∼500V Cr). Monte Carlo simulations based on Heisenberg model suggest markedly high Curie temperatures of these monolayers (∼200 K). Besides, their high mechanical, dynamical, and thermal stabilities are further verified by elastic constants, phonon dispersion calculations, andmolecular dynamics simulations. The outstanding attributes render CrXTe(X = Si, Ge) monolayers broadening the candidates of 2D FMS for a wide range of applications.
二维（2D）铁磁半导体（FMS）为纳米级器件中的量子信息技术发展提供了理想平台。然而，它们中的大多数都存在居里温度低和磁各向异性能（MAE）小的问题，严重限制了其实际应用。在这项工作中，通过第一性原理计算，我们预测了两种稳定的二维材料，即CrSiTe和CrGeTe单层。有趣的是，它们都是本征直接带隙FMS（1 eV），具有大的磁化强度（8 f.u.）和可观的MAE（500 V Cr）。基于海森堡模型的蒙特卡罗模拟表明这些单层具有明显较高的居里温度（~200 K）。此外，弹性常数、声子色散计算和分子动力学模拟进一步验证了它们高的力学、动力学和热稳定性。这些优异的特性使得CrXTe（X = Si，Ge）单层拓宽了二维FMS在广泛应用中的候选材料范围。
