Rare earth element doping effect on the bonding and the transport property of δ-MoN

• Published in: Theoretical chemistry accounts Vol. 128; no. 3; pp. 285 - 293
• Main Authors: Yu, Jing, Zhang, Guiling, Shang, Yan, Zhang, Hui, Yang, Luqing, Zeng, Tao, Liu, Bo, Li, Zesheng
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.02.2011
• Subjects: Atomic/Molecular Structure and Spectra; Chemistry; Chemistry and Materials Science; Inorganic Chemistry; Organic Chemistry; Physical Chemistry; Regular Article; Theoretical and Computational Chemistry; Theoretical study; Rare earth element; Doping effect; δ-MoN
• ISSN: 1432-881X; 1432-2234
• DOI: 10.1007/s00214-010-0845-0

Combining non-equilibrium Green’s function technique with density functional theory, the rare earth element doping effect on the bonding and the transport property of δ-MoN were theoretically investigated. The Mo–N bond lengths become more uneven after dopings. Some Mo–N bonds were heavily lengthened by the La- and Gd-dopings, resulting in obvious damages of their bonding. Evident covalent-like La–N and Gd–N bonds were formed in La–MoN and Gd–MoN, respectively, while the Yb atom underwent an ionic-like interaction with its neighboring N atoms in Yb–MoN. A clear drop of the conductivity was found after La- and Gd-dopings. On the contrary, the conductivity was improved upon the Yb-doping. This case was rationalized from the carrier density and the scattering of the carriers. The backscattering effect was evident at the impurities. The La- and Gd-dopings could not effectively increase the carrier density near the Fermi level, while the Yb atom could offer f -carriers to transfer from the valence band to the conduction band.