Structural studies of TiC_1?xO_x solid solution by Rietveld refinement and first-principles calculations

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• 作者：Bo Jiang ; Na Hou ; Shanyan Huang ; Gege Zhou ; Jungang Hou ; Zhanmin Cao ; Hongmin Zhu
• 关键词：Titanium oxycarbides ; Structural properties ; Rietveld refinement ; First-principles
• 刊名：Journal of Solid State Chemistry
• 出版年：2013
• 出版时间：August, 2013
• 年：2013
• 卷：204
• 期：Complete
• 页码：1-8
• 全文大小：3342 K

文摘

The lattice parameters, structural stability and electronic structure of titanium oxycarbides (TiC_1?xO_x, 0¡Üx¡Ü1) solid solution were investigated by Rietveld refinement and first-principles calculations. Series of TiC_1?xO_x were precisely synthesized by sintering process under the vacuum. Rietveld refinement results of XRD patterns show the properties of continuous solid solution in TiC_1?xO_x over the whole composition range. The lattice parameters vary from 0.4324 nm to 0.4194 nm decreasing with increasing oxygen concentration. Results of first-principles calculations reveal that the disorder C/O structure is stable than the order C/O structure. Further investigations of the vacancy in Ti_1?Va(C_1?xO_x)_1?Va solid solution present that the structure of vacancy segregated in TiO-part is more stable than the disorder C/O structure, which can be ascribed to the Ti-Ti bond across O-vacancy and the charge redistributed around Ti-vacancy via the analysis of the electron density difference plots and PDOS.