Liu Yinqiao, Liu Qinxi, Liu Ying, Jiang Xue, Zhang Xiaoliang, Zhao Jijun
Key Laboratory of Material Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education, Dalian 116024, China.
Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, School of Energy and Power Engineering, Dalian University of Technology, Dalian 116024, China.
Nanoscale. 2021 Apr 30;13(16):7714-7722. doi: 10.1039/d0nr08626f.
The contributions of spin-phonon coupling (SPC) to spin and thermal transport properties are important in emerging two-dimensional (2D) magnetic semiconductors and are relevant to the data security and working stability of spin-based devices. By evaluating the dynamical stability of both ferromagnetic (FM) and paramagnetic (PM) states at 0 K, six transition-metal trihalides, namely FeCl3, FeBr3, FeI3, RuCl3, RuBr3, and RuI3, are identified as ideal 2D magnetic semiconductors for investigating SPC. For these compounds, we perform first-principles calculations to evaluate the spin-relative lattice constants, bond angles, phonon dispersions, lattice thermal conductivity, as well as phonon-relative magnetic coupling parameters, magnetic moment, and Curie temperature. Our results suggest weaker SPC effects on Ru trihalides and stronger SPC effects on Fe trihalides. To explain these observations, we further analyze the SPC induced heat capacity, group velocity, scattering possibility, phonon anharmonicity, and phonon-magnon scattering. More importantly, we also provide a unified explanation for the SPC role in causing anomalous lattice thermal conductivity and stabilizing the ferromagnetic/antiferromagnetic ordering. The present study offers not only in-depth knowledge about the mechanisms of SPC regarding the spin and thermal transport behavior of 2D FM semiconductors, but also a better understanding of thermal management and control in magnetic quantum materials.
自旋 - 声子耦合（SPC）对自旋和热输运性质的贡献在新兴的二维（2D）磁性半导体中很重要，并且与自旋基器件的数据安全性和工作稳定性相关。通过评估0 K时铁磁（FM）和顺磁（PM）态的动力学稳定性，确定了六种过渡金属三卤化物，即FeCl3、FeBr3、FeI3、RuCl3、RuBr3和RuI3，为研究SPC的理想二维磁性半导体。对于这些化合物，我们进行第一性原理计算，以评估自旋相对晶格常数、键角、声子色散、晶格热导率，以及声子相对磁耦合参数、磁矩和居里温度。我们的结果表明，SPC对钌三卤化物的影响较弱，对铁三卤化物的影响较强。为了解释这些观察结果，我们进一步分析了SPC诱导的热容量、群速度、散射可能性、声子非谐性和声子 - 磁振子散射。更重要的是，我们还对SPC在导致异常晶格热导率和稳定铁磁/反铁磁有序方面的作用提供了统一解释。本研究不仅提供了关于SPC在二维FM半导体自旋和热输运行为方面机制的深入知识，还增进了对磁性量子材料中热管理和控制的理解。
