Thermal transport and microscopic dynamics in filled skutterudite YbFe4Sb12 studied by ab initio molecular dynamics simulation
文献类型：期刊论文
| 作者 | Wang Yan-Cheng; Qiu Wu-Jie; Yang Hong-Liang; Xi Li-Li; Yang Jiong; Zhang Wen-Qing |
| 刊名 | ACTA PHYSICA SINICA
 |
| 出版日期 | 2018 |
| 卷号 | 67期号:1 |
| 关键词 | filled skutterudite finite temperature correlation of atoms beyond three-phonon scattering |
| ISSN号 | 1000-3290 |
| DOI | 10.7498/aps.67.20171406 |
| 英文摘要 | Filled skutterudite is a typical thermoelectric material with high thermoelectric figure of merit at intermediate temperatures. One of the important features is the low lattice thermal conductivity (k(L)) caused by the low frequency vibrations of filler atoms in the oversized void cages. In the past decades, it has been still under debate whether the underlying phonon scattering mechanism should be considered to be resonant scattering or enhanced three-phonon process. To clarify the role played by the filler atoms in reducing the lattice thermal conductivity, we study the microscopic dynamical process of filler and related interactions by means of ab initio molecular dynamics (AIMD) and temperature dependent effective potential (TDEP) technique. Firstly, we simulate the dynamical trajectories of fully filled skutterudite YbFe4Sb12 at different temperatures through AIMD. In this approach, the nonlinear guest-host interactions at finite temperatures are taken into consideration naturally from dynamical trajectories. Then, we extract the effective temperature-dependent harmonic and anharmonic interatomic force constants (IFCs) by TDEP method through the statistical analyses of both trajectories and forces. The atomic participation ratios and lifetimes of phonon modes are calculated based on the effective IFCs. The results demonstrate that the local vibration modes of Yb couple with acoustic branches and reduce the lifetimes of the lattice phonons significantly. However, the calculated k(L), which is on the assumption that the filler interacts with lattice phonons through three-phonon collision, still deviates from the experimental result. In order to rationalize the discrepancy, we analyze the correlation properties between different Yb atoms by velocity coherence in atomic dynamical motions. The localized and independent vibration characteristic of Yb is found in this analysis. This implies that the motions of Yb atoms deviate from the periodic and collective vibration excitation paradigm of phonon. Therefore, the mechanism for how filler atoms scatter lattice phonon and enhance thermal resistance is beyond three-phonon scattering process. We thus introduce resonant scattering into the lifetimes of Yb-dominant localized vibration modes, and so-calculated k(L) is in a good agreement with the experimental data. Overall, we come to a conclusion that both the phonon-phonon interaction and the resonant scattering due to the localized oscillators cause the low lattice thermal conductivity of YbFe4Sb12. |
| 学科主题 | Physics, Multidisciplinary |
| WOS记录号 | WOS:000425271100027 |
| 出版者 | CHINESE PHYSICAL SOC |
| 资助机构 | Project supported by the National Natural Science Foundation of China (Grant Nos. 51632005, 51572167, 11574333). ; Project supported by the National Natural Science Foundation of China (Grant Nos. 51632005, 51572167, 11574333). |
| 源URL | [http://ir.sic.ac.cn/handle/331005/24559]  |
| 专题 | 中国科学院上海硅酸盐研究所 |
| 作者单位 | 1.[Wang Yan-Cheng 2.Qiu Wu-Jie 3.Yang Hong-Liang 4.Chinese Acad Sci, Shanghai Inst Ceram, State Key Lab High Performance Ceram & Superfine, Shanghai 200050, Peoples R China 5.[Wang Yan-Cheng 6.Univ Chinese Acad Sci, 19 Yuquan Rd, Beijing 100049, Peoples R China 7.[Xi Li-Li 8.Yang Jiong 9.Shanghai Univ, Mat Genome Inst, Shanghai 200444, Peoples R China |
| 推荐引用方式 GB/T 7714 | Wang Yan-Cheng,Qiu Wu-Jie,Yang Hong-Liang,et al. Thermal transport and microscopic dynamics in filled skutterudite YbFe4Sb12 studied by ab initio molecular dynamics simulation[J]. ACTA PHYSICA SINICA,2018,67(1). |
| APA | Wang Yan-Cheng,Qiu Wu-Jie,Yang Hong-Liang,Xi Li-Li,Yang Jiong,&Zhang Wen-Qing.(2018).Thermal transport and microscopic dynamics in filled skutterudite YbFe4Sb12 studied by ab initio molecular dynamics simulation.ACTA PHYSICA SINICA,67(1). |
| MLA | Wang Yan-Cheng,et al."Thermal transport and microscopic dynamics in filled skutterudite YbFe4Sb12 studied by ab initio molecular dynamics simulation".ACTA PHYSICA SINICA 67.1(2018). |
入库方式： OAI收割
来源：上海硅酸盐研究所
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