First-principle study of electronic properties of Ti₃Si_1−xAl_xC₂ solid solutions

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• 作者：Xu Xu ; Erdong Wu ; Xiaoming Du ; Yongjun Tian ; Julong He
• 关键词：A. Ceramics ; C. Ab initio calculations ; D. Electronic structure ; D. Electrical conductivity
• 刊名：Journal of Physics and Chemistry of Solids
• 出版年：2008
• 期刊代码：69_00223697
• 类别：ch
• 出版时间：May-June 2008
• 卷：69
• 期：5-6
• 页码：1356-1361
• 文件大小：899 K

摘要

The layered ternary ceramics Ti₃SiC₂ and Ti₃AlC₂ are isostructural and can form Ti₃Si_1−xAl_xC₂ solid solutions combining the advanced properties of both compounds [H.B. Zhang, Y.C. Zhou, Y.W. Bao, M.S. Li, Improving the oxidation resistance of Ti₃SiC₂ by forming a Ti₃Si_0.90Al_0.1C₂ solid solution, Acta Mater. 52 (2004) 3631–3637; E.D. Wu, J.Y. Wang, H.B. Zhang, Y.C. Zhou, K. Sun, Y.J. Xue, Neutron diffraction studies of Ti₃Si_0.9Al_0.1C₂ compound, Mater. Lett. 59 (2005) 2715–2719; J.Y. Wang, Y.C. Zhou, First-principles study of equilibrium properties and electronic structure of Ti₃Si_0.75Al_0.25C₂ solid solution, J. Phys.: Condens. Matter 15 (2003) 5959–5968; Y.C. Zhou, J.X. Chen, J.Y. Wang, Strengthening of Ti₃AlC₂ by incorporation of Si to form Ti₃Al_1−xSi_xC₂ solid solutions, Acta. Mater. 54 (2006) 1317–1322]. In the present work, the solid solutions of Ti₃Si_1−xAl_xC₂ (x=0, 0.25, 0.33, 0.5, 0.67, 0.75, 1) are investigated by first-principle calculations based on pseudo-potential plan-wave method within the density functional theory framework. The results show that as Al content increases in the solid solution, all the bonds have weakened to certain extents, which lead to an unstable structure both energetically and geometrically. The calculated results are compared and discussed with the reported data for the Ti₃Si_1−xAl_xC₂ solid solutions.