Wang Shiyao, Miao Nanxi, Su Kehe, Blatov Vladislav A, Wang Junjie
State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, People's Republic of China.
School of Chemistry and Chemical Engineering, Nowthwestern Polytechnical University, Xi'an, Shaanxi 710072, People's Republic of China.
Nanoscale. 2021 May 6;13(17):8254-8263. doi: 10.1039/d1nr01103k.
Intrinsic two-dimensional (2D) magnets are promising materials for developing advanced spintronic devices. A few have already been synthesized from the exfoliation of van der Waals magnetic materials. In this work, by using ab initio calculations and Monte Carlo simulation, a series of 2D MBs (M = Cr, Mn or Fe; B = boron) are predicted possessing robust magnetism, sizeable magnetic anisotropy energy, and excellent structural stability. These 2D MBs can be respectively synthesized from non-van der Waals compounds with low separation energies such as Cr2AlB2, Mn2AlB2, and Fe2AlB2. 2D CrB is a ferromagnetic (FM) metal with a weak in-plane magnetic anisotropy energy of 23.6 μeV per atom. Metallic 2D MnB and FeB are Ising antiferromagnets with an out-of-plane magnetic easy axis and robust magnetic anisotropy energies up to 222.7 and 482.2 μeV per atom, respectively. By using Monte Carlo simulation, the critical temperatures of 2D CrB, MnB, and FeB were calculated to be 440 K, 300 K, and 320 K, respectively. Our study found that the super-exchange interaction plays the dominant role in determining the long-range magnetic ordering of 2D MBs. Moreover, most functionalized 2D MBTs (T = O, OH or F) are predicted to have AFM ground states. Alternating transition metals or functional groups can significantly modulate the magnetic ground state and critical temperature of 2D MBTs. This study suggests that the 2D MBs and MBTs are promising metallic 2D magnets for spintronic applications.
本征二维（2D）磁体是开发先进自旋电子器件的有前途的材料。已经通过范德华磁性材料的剥离合成了一些。在这项工作中，通过使用从头算计算和蒙特卡罗模拟，预测了一系列二维MB（M = Cr、Mn或Fe；B = 硼）具有强磁性、可观的磁各向异性能量和出色的结构稳定性。这些二维MB可以分别由具有低分离能的非范德华化合物如Cr2AlB2、Mn2AlB2和Fe2AlB2合成。二维CrB是一种铁磁（FM）金属，每个原子的面内磁各向异性能量较弱，为23.6 μeV。金属二维MnB和FeB是伊辛反铁磁体，具有面外易磁轴，每个原子的磁各向异性能量分别高达222.7和482.2 μeV。通过蒙特卡罗模拟，二维CrB、MnB和FeB的临界温度分别计算为440 K、300 K和320 K。我们的研究发现，超交换相互作用在决定二维MB的长程磁有序中起主导作用。此外，预测大多数功能化的二维MBT（T = O、OH或F）具有反铁磁基态。交替的过渡金属或官能团可以显著调节二维MBT的磁基态和临界温度。这项研究表明，二维MB和MBT是用于自旋电子应用的有前途的金属二维磁体。
