First-principles investigations of isotope effects in thermodynamic properties of TiX2 (X = H, D, and T) system
文献类型：期刊论文
| 作者 | C. H. Hu ; D. M. Chen ; Y. M. Wang ; K. Yang |
| 刊名 | Journal of Alloys and Compounds
 |
| 出版日期 | 2008 |
| 卷号 | 450期号:1-2页码:369-374 |
| 关键词 | isotope effects thermodynamic properties density-functional perturbation theory quasiharmonic approximation functional perturbation-theory neutron spectroscopy thermal-properties titanium hydrogen dependence expansion constants palladium hydrides |
| ISSN号 | 0925-8388 |
| 中文摘要 | As hydrogen, deuterium and tritium storage materials, a series of investigations of mechanical and thermal properties of titanium hydrides, deuterides and tritides have been performed, however, very limited theoretical studies of thermodynamic properties for them can be found. Based on density-functional theory (DFT) and density-functional perturbation theory (DFPT) we have discussed systematically the hydrogen isotope effects on the thermodynamic properties of TiX2 (X = H, D, and T) system. Our calculations indicate that for evaluating accurately their physical properties at absolute zero temperature, such as the equilibrium lattice constants, bulk modulus, and heat of formation, the zero-point energy correction must be taken into account. By performing the phonon calculation within quasiharmonic approximation (QHA), we obtain their vibrational free energies, vibrational entropies, and temperature dependence of specific heat, thermal expansion, and bulk modulus. Those results demonstrate that comparing with TiH2, TiT2 and TiD2 are more stable and the zero-point effects play an important role in their thermal expansion. The increase in the force constant between Ti and H causes the higher value of specific heat of TiH2 during the phase transition from FCC to FCT. In addition, comparing with available experimental values, we can conclude that QHA is feasible for describing the thermal properties of TiX2. (C) 2006 Elsevier B.V. All rights reserved. |
| 原文出处 | |
| 公开日期 | 2012-04-13 |
| 源URL | [http://210.72.142.130/handle/321006/32818]  |
| 专题 | 金属研究所_中国科学院金属研究所 |
| 推荐引用方式 GB/T 7714 | C. H. Hu,D. M. Chen,Y. M. Wang,et al. First-principles investigations of isotope effects in thermodynamic properties of TiX2 (X = H, D, and T) system[J]. Journal of Alloys and Compounds,2008,450(1-2):369-374. |
| APA | C. H. Hu,D. M. Chen,Y. M. Wang,&K. Yang.(2008).First-principles investigations of isotope effects in thermodynamic properties of TiX2 (X = H, D, and T) system.Journal of Alloys and Compounds,450(1-2),369-374. |
| MLA | C. H. Hu,et al."First-principles investigations of isotope effects in thermodynamic properties of TiX2 (X = H, D, and T) system".Journal of Alloys and Compounds 450.1-2(2008):369-374. |
入库方式： OAI收割
来源：金属研究所
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