中國有色金屬學報(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 19 No. 1 February 2009 |
（1. Department of Physics, Institute of Theoretical Physics and Astrophysics, Xiamen University,
Xiamen 361005, China;
2. State Key Lab for Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen 361005, China;
3. Department of Physics, Fudan University, Shanghai 200433, China）
Abstract:Na-substituted dilithium orthosilicate Li2CoSiO4 was investigated by performing density functional theory calculations within the GGA+U framework. The effects of Na-substitution on the electronic structures and structural properties of Li2CoSiO4 were presented. The results show that the Na-substitution on Li sites in Li2CoSiO4 induces a lowering of the conduction bands and a narrowing of the band gap, which could be helpful for enhancing the electronic conductivity. On the other hand, the Na-substitution on the Li ions in Li2CoSiO4 leads to the expansion of interlayer space of the adjacent corrugated layers. This lattice expansion effect would benefit the Li ion diffusion.
Key words: dilithium cobalt orthosilicate; Na-substitution; structural properties; electronic structures
