中國有色金屬學報(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 24 No. 6 June 2014 |
（1. College of Mathematics and Computer Science, Key Laboratory of High Performance Computing and Stochastic Information Processing (Ministry of Education), Hunan Normal University, Changsha 410081, China;
2. School of Physics and Electronics, Central South University, Changsha 410083, China;
3. School of Electrical and Information Engineering, Hunan International Economics University,
Changsha 410205, China）
Abstract:The electronic structures, chemical bonding, elastic and optical properties of the ternary stannide phase Na2MgSn were investigated by using density-functional theory (DFT) within generalized gradient approximation (GGA). The calculated energy band structures show that Na2MgSn is an indirect semiconductor material with a narrow band gap 0.126 eV. The density of state (DOS) and the partial density of state (PDOS) calculations show that the DOS near the Fermi level is mainly from the Na 2p, Mg 3p and Sn 5p states. Population analysis suggests that there are strongly bonded Mg-Sn honeycomb layers in Na2MgSn. Basic physical properties, such as lattice constant, bulk modulus, shear modulus, elastic constants cij were calculated. The elastic modulus E and Poisson ratio ν were also predicted. The results show that Na2MgSn is mechanically stable soft material and behaves in a brittle manner. Detailed analysis of all optical functions reveals that Na2MgSn is a better dielectric material, and reflectivity spectra show that Na2MgSn promise as good coating materials in the energy regions 6.24-10.49 eV.
Key words: stannide phase Na2MgSn; first principles; electronic structures; chemical bonding; elastic properties; optical properties
