Tan Xingyi, Liu Lili, Xiang Hui, Du Gui-Fang, Lou Ao, Fu Hua-Hua
Department of Physics, Chongqing Three Gorges University, Wanzhou, 404100, People's Republic of China.
Nanoscale. 2020 Apr 30;12(16):8942-8948. doi: 10.1039/c9nr10849a.
One-dimensional (1D) materials with robust ferromagnetic ground states are difficult to achieve but provide a significant platform for potential spintronic device applications in future. Herein, a new family of 1D transition metal dihalide (TMCl2; where TM = Cu, Co, Cr) nanowires are proposed by using first-principles calculations. Their dynamic stability is ensured by Born-Oppenheimer molecular dynamics simulations. The electronic structures demonstrate that both CoCl2 and CuCl2 nanowires are promising bipolar magnetic semiconductors (BMSs) and can be converted into 1D half-metal materials by a small amount of carrier doping. The CrCl2 nanowire is an antiferromagnetic semiconductor (AFS). The formation of a BMS is attributed to the superexchange coupling between the Co/Cu atoms through the 3p orbitals in the Cl atoms. By using Monte Carlo simulations, we found that the CoCl2 nanowire has a Curie point of 6 K, while the CuCl2 nanowire has a corresponding Curie point of 14 K. Our results allow us to put forward a strategy to realize 1D BMSs and to design low-dimensional AF spintronic devices.
具有稳健铁磁基态的一维（1D）材料难以实现，但为未来潜在的自旋电子器件应用提供了一个重要平台。在此，通过第一性原理计算提出了一类新型的一维过渡金属二卤化物（TMCl2；其中TM = Cu、Co、Cr）纳米线。通过玻恩-奥本海默分子动力学模拟确保了它们的动力学稳定性。电子结构表明，CoCl2和CuCl2纳米线都是有前景的双极磁半导体（BMS），并且通过少量载流子掺杂可以转变为一维半金属材料。CrCl2纳米线是反铁磁半导体（AFS）。BMS的形成归因于Co/Cu原子通过Cl原子中的3p轨道的超交换耦合。通过蒙特卡罗模拟，我们发现CoCl2纳米线的居里点为6 K，而CuCl2纳米线的相应居里点为14 K。我们的结果使我们能够提出一种实现一维BMS并设计低维反铁磁自旋电子器件的策略。
