Center for Applied Physics and Technology, College of Engineering, Peking University, Beijing 100871, China.
Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, China.
Sci Rep. 2014 Jun 10;4:5241. doi: 10.1038/srep05241.
Design and synthesis of two-dimensional (2D) materials with robust ferromagnetism and biocompatibility is highly desirable due to their potential applications in spintronics and biodevices. However, the hotly pursued 2D sheets including pristine graphene, monolayer BN, and layered transition metal dichalcogenides are nonmagnetic or weakly magnetic. Using biomimetic particle swarm optimization (PSO) technique combined with ab initio calculations we predict the existence of a 2D structure, a monolayer of rocksalt-structured CrN (100) surface, which is both ferromagnetic and biocompatible. Its dynamic, thermal and magnetic stabilities are confirmed by carrying out a variety of state-of-the-art theoretical calculations. Analyses of its band structure and density of states reveal that this material is half-metallic, and the origin of the ferromagnetism is due to p-d exchange interaction between the Cr and N atoms. We demonstrate that the displayed ferromagnetism is robust against thermal and mechanical perturbations. The corresponding Curie temperature is about 675 K which is higher than that of most previously studied 2D monolayers.
设计和合成具有强铁磁性和生物相容性的二维（2D）材料是非常理想的，因为它们在自旋电子学和生物器件中有潜在的应用。然而，人们热切追求的二维薄片包括原始石墨烯、单层 BN 和层状过渡金属二卤化物都是非磁性或弱磁性的。本研究采用仿生粒子群优化（PSO）技术与第一性原理计算相结合，预测了一种二维结构，即具有岩盐结构的 CrN（100）表面的单层，该单层既具有铁磁性又具有生物相容性。通过进行各种最先进的理论计算，证实了其动力学、热稳定性和磁稳定性。对其能带结构和态密度的分析表明，这种材料是半金属的，铁磁性源于 Cr 和 N 原子之间的 p-d 交换相互作用。我们证明了所展示的铁磁性对热和机械扰动具有鲁棒性。相应的居里温度约为 675 K，高于之前研究过的大多数二维单层材料。
