Wu Yaxuan, Sun Wei, Liu Siyuan, Wang Bing, Liu Chang, Yin Huabing, Cheng Zhenxiang
Institute for Computational Materials Science, School of Physics and Electronics, Henan University, 475004, Kaifeng, People's Republic of China.
International Joint Research Laboratory of New Energy Materials and Devices of Henan Province, 475004, Kaifeng, People's Republic of China.
Nanoscale. 2021 Oct 14;13(39):16564-16570. doi: 10.1039/d1nr04816c.
Searching for experimentally feasible intrinsic two-dimensional ferromagnetic semiconductors is of great significance for applications of nanoscale spintronic devices. Here, based on the first-principles calculations, an Ni(NCS) monolayer was systematically investigated. The results showed that the Ni(NCS) monolayer was a robust bipolar ferromagnetic semiconductor with a moderate bandgap of ∼1.5 eV. Based on the Monte Carlo simulation, its Curie temperature was about 37 K. Interestingly, the Ni(NCS) monolayer remains ferromagnetic ordering when strain and electron doping were applied. However, ferromagnetic-to-antiferromagnetic phase transition occurred when high concentrations of holes were doped. Besides, the Ni(NCS) monolayer is confirmed to be potentially exfoliated from its bulk forms due to its small exfoliated energy. Finally, the Ni(NCS) monolayer's thermodynamic, dynamic, and mechanical stabilities were confirmed by the phonon spectrum calculation, molecular dynamics simulation and elastic constants calculation, respectively. The results showed that the Ni(NCS) monolayer, as a novel 2D ferromagnetic candidate material of new magnetic molecular framework materials, may have a promising potential for magnetic nanoelectronic devices.
寻找实验上可行的本征二维铁磁半导体对于纳米级自旋电子器件的应用具有重要意义。在此，基于第一性原理计算，对单层Ni(NCS)进行了系统研究。结果表明，单层Ni(NCS)是一种稳健的双极铁磁半导体，带隙适中，约为1.5 eV。基于蒙特卡罗模拟，其居里温度约为37 K。有趣的是，施加应变和电子掺杂时，单层Ni(NCS)仍保持铁磁有序。然而，当掺杂高浓度空穴时，会发生铁磁到反铁磁的相变。此外，由于其较小的剥离能，证实单层Ni(NCS)有可能从其体相形式中剥离出来。最后，分别通过声子谱计算、分子动力学模拟和弹性常数计算证实了单层Ni(NCS)的热力学、动力学和机械稳定性。结果表明，单层Ni(NCS)作为新型磁性分子骨架材料的二维铁磁候选材料，在磁性纳米电子器件方面可能具有广阔的应用前景。
