Hu Y, Gong Y H, Zeng H H, Wang J H, Fan X L
State Key Laboratory of Solidification Processing, Center for Advanced Lubrication and Seal Materials, School of Material Science and Engineering, Northwestern Polytechnical University, 127 YouYi Western Road, Xi'an, Shaanxi 710072, China.
Queen Mary University of London Engineering School, Northwestern Polytechnical University, 127 YouYi Western Road, Xi'an, Shaanxi 710072, China.
Phys Chem Chem Phys. 2020 Nov 4;22(42):24506-24515. doi: 10.1039/d0cp03991h.
Two-dimensional (2D) ferromagnetic (FM) semiconductors are highly desirable in next generation spintronic devices. Herein, we report an intrinsic FM semiconductor, an FeI3 monolayer which can be exfoliated from its bulk crystal owing to the small cleavage energy and the high in-plane stiffness. The FeI3 monolayer is dynamically and mechanically stable. Additionally, the FeI3 monolayer has sizable magneto-crystalline anisotropy energy (MAE) and the Curie temperature is higher than the liquid-nitrogen temperature (77 K), and there is a big discrepancy (Δcbm) between the conduction band minimum of the two spin-channels and negligible thermally induced hop. Carrier doping less than 0.1 e per unit cell further improves the relevant properties by modulating the MAE, Curie temperature, and Δcbm. Moreover, the isoelectronic analogue FeI1.5Cl1.5 monolayer is a bipolar FM semiconductor with a high Curie temperature (260 K). Our results demonstrate promising applications of the FeI3 monolayer in next-generation spintronic devices owing to its robust intrinsic ferromagnetism and novel semiconducting properties.
二维（2D）铁磁（FM）半导体在下一代自旋电子器件中极具吸引力。在此，我们报道了一种本征FM半导体，即FeI3单层，由于其较小的解理能和较高的面内刚度，它可以从其体晶体中剥离出来。FeI3单层在动力学和力学上是稳定的。此外，FeI3单层具有可观的磁晶各向异性能量（MAE），居里温度高于液氮温度（77 K），并且两个自旋通道的导带最小值之间存在较大差异（Δcbm），热诱导跃迁可忽略不计。每单位晶胞载流子掺杂小于0.1 e通过调节MAE、居里温度和Δcbm进一步改善了相关性能。此外，等电子类似物FeI1.5Cl1.5单层是一种具有高居里温度（260 K）的双极FM半导体。我们的结果表明，由于FeI3单层具有强大的本征铁磁性和新颖的半导体特性，它在下一代自旋电子器件中具有广阔的应用前景。
