Xiang Hui, Xu Bo, Zhao Weiqian, Xia Yidong, Yin Jiang, Zhang Xiaofei, Liu Zhiguo
School of Mathematics and Physics, Hubei Polytechnic University Huangshi 435003 China
National Laboratory of Solid State Microstructures, Department of Materials Science and Engineering, Nanjing University Nanjing 210093 China
RSC Adv. 2019 May 2;9(24):13561-13566. doi: 10.1039/c9ra01218d. eCollection 2019 Apr 30.
The magnetism of hole doped 1T-MX (M = Zr, Hf; X = S, Se) monolayers is systematically studied by using first principles density functional calculations. The pristine 1T-MX monolayers are semiconductors with nonmagnetic ground states, which can be transformed to ferromagnetic states by the approach of hole doping. For the unstrained monolayers, the spontaneous magnetization appears once above the critical hole density (10 cm), where the p orbital of S or Se atoms contributes the most of the magnetic moment. As the tensile strains exceed 4%, the magnetic moments per hole of ZrS and HfS monolayers increase sharply to a saturated value with increasing hole density, implying obvious advantages over the unstrained monolayers. The phonon dispersion calculations for the strained ZrS and HfS monolayers indicate that they can keep the dynamical stability by hole doping. Furthermore, we propose that the fluorine atom modified ZrS monolayer could obtain stable ferromagnetism. The magnetism in hole doped 1T-MX (M = Zr, Hf; X = S, Se) monolayers has great potential for developing spintronic devices with desirable applications.
通过第一性原理密度泛函计算系统地研究了空穴掺杂的1T-MX（M = Zr，Hf；X = S，Se）单层的磁性。原始的1T-MX单层是具有非磁性基态的半导体，通过空穴掺杂的方法可以转变为铁磁态。对于无应变的单层，一旦超过临界空穴密度（10 cm）就会出现自发磁化，其中S或Se原子的p轨道对磁矩的贡献最大。当拉伸应变超过4%时，ZrS和HfS单层的每个空穴的磁矩随着空穴密度的增加而急剧增加到饱和值，这意味着相对于无应变的单层具有明显优势。对应变的ZrS和HfS单层的声子色散计算表明，它们可以通过空穴掺杂保持动力学稳定性。此外，我们提出氟原子修饰的ZrS单层可以获得稳定的铁磁性。空穴掺杂的1T-MX（M = Zr，Hf；X = S，Se）单层中的磁性在开发具有理想应用的自旋电子器件方面具有巨大潜力。
