Ferromagnetic Half-Metal Cyanamides Cr(NCN)<sub>2</sub> Predicted from First Principles Investigation
Zhilue Wang,
Shoujiang Qu,
Hongping Xiang,
Zhangzhen He,
Jun Shen
Affiliations
Zhilue Wang
School of Materials Science and Engineering, Tongji University, 4800 Caoan Road, Shanghai 201804, China
Shoujiang Qu
School of Materials Science and Engineering, Tongji University, 4800 Caoan Road, Shanghai 201804, China
Hongping Xiang
School of Materials Science and Engineering, Tongji University, 4800 Caoan Road, Shanghai 201804, China
Zhangzhen He
State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China
Jun Shen
School of Materials Science and Engineering, Tongji University, 4800 Caoan Road, Shanghai 201804, China
The stability, physical properties, and electronic structures of Cr(NCN)2 were studied using density functional theory with explicit electronic correlation (GGA+U). The calculated results indicate that Cr(NCN)2 is a ferromagnetic and half-metal, both thermodynamically and elastically stable. A comparative study on the electronic structures of Cr(NCN)2 and CrO2 shows that the Cr atoms in both compounds are in one crystallographically equivalent site, with an ideal 4+ valence state. In CrO2, the Cr atoms at the corner and center sites have different magnetic moments and orbital occupancies, moreover, there is a large difference between the intra- (12.1 meV) and inter-chain (31.2 meV) magnetic couplings, which is significantly weakened by C atoms in Cr(NCN)2.
