Jiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy Application, School of Physical Science and Technology, Suzhou University of Science and Technology, Suzhou, 215009, China.
Phys Chem Chem Phys. 2023 Jun 7;25(22):15469-15478. doi: 10.1039/d3cp00535f.
Two-dimensional magnetic materials with tunable electronic properties have great potential application in spintronic devices. Here, based on first-principles calculations, we systematically study the electronic structures and magnetic properties of monolayer NiMnBr. The magnetic ground state of monolayer NiMnBr is Néel ferrimagnetic (FIM-Néel) with a critical temperature () of 45 K. The magnetic properties of monolayer NiMnBr can be tuned effectively by strain. The magnetic phase transition from the FIM-Néel state to the ferromagnetic (FM) state can be triggered by applying a compressive strain greater than 4.5%. The of the FIM-Néel state and FM state can be increased to 67 K and 95 K by applying 8.0% tensile and compressive strain, respectively. Monolayer NiMnBr in both the FIM-Néel state and FM state has large magnetic anisotropy energy. Remarkably, the monolayer NiMnBr in the FIM-Néel state acts as a bipolar ferrimagnetic semiconductor (BFIMS), while the compressive strained monolayer NiMnBr in the FM state acts as a half FM semiconductor (HFMS). The magnetic configuration of monolayer NiMnBr can also be tuned by carrier doping. Interestingly, for monolayer NiMnBr with the HFMS phase, the magnetic phase transition from the FM state to FIM-Néel state can be achieved with the increase of the hole doping concentration, which leads to the achievement of a doping concentration induced carrier spin flip. Our results show that monolayer NiMnBr is a promising candidate for exploring two-dimensional magnetism and spintronic devices.
具有可调谐电子特性的二维磁性材料在自旋电子器件中有很大的潜在应用。在这里，我们基于第一性原理计算，系统地研究了单层 NiMnBr 的电子结构和磁性。单层 NiMnBr 的磁基态是尼尔反铁磁（FIM-Néel），临界温度（）为 45 K。应变可以有效地调节单层 NiMnBr 的磁性。通过施加大于 4.5%的压缩应变，可以触发从 FIM-Néel 态到铁磁（FM）态的磁相变。通过施加 8.0%的拉伸和压缩应变，FIM-Néel 态和 FM 态的分别可以增加到 67 K 和 95 K。处于 FIM-Néel 态和 FM 态的单层 NiMnBr 都具有较大的磁各向异性能。值得注意的是，处于 FIM-Néel 态的单层 NiMnBr 是一种双极反铁磁半导体（BFIMS），而处于 FM 态的压缩应变单层 NiMnBr 是一种半 FM 半导体（HFMS）。通过载流子掺杂也可以调节单层 NiMnBr 的磁性构型。有趣的是，对于具有 HFMS 相的单层 NiMnBr，随着空穴掺杂浓度的增加，可以实现从 FM 态到 FIM-Néel 态的磁相变，从而实现掺杂浓度诱导的载流子自旋翻转。我们的结果表明，单层 NiMnBr 是探索二维磁性和自旋电子器件的有前途的候选材料。
