| 研究課題/領域番号 |
21J21731
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| 配分区分 | 補助金 |
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| 研究機関 | 東京大学 |
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研究代表者 |
MENG HAN 東京大学, 工学系研究科, 特別研究員(DC1)
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| 研究期間 (年度) |
2021-04-28 – 2024-03-31
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| キーワード | Ternary alloy / Nanostructure / Thermoelectrics / Benchmarking / First principle / Cluster expansion / Monte Carlo simulation |
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| 研究実績の概要 |
The research achievements of three works conducted in the past year are summarized as follows.
1. The research on thermoelectric performance of ternary alloys based on structure prediction: 1) A database was prepared with a number of structures and their formation energies obtained from first-principle calculations. 2) The cluster expansion was constructed by training effective cluster interactions; 3) Structures were predicted for alloys of different compositions by Monte Carlo simulations; 4) Thermal conductivity and electrical properties were calculated for alloys of different compositions. 5) Power factor and ZT were calculated by combining thermal conductivity and electrical properties.
2. The research on thermoelectric performance of nanostructured multiphase material: 1) Thermal conductivities were calculated for both two phases by relaxation time approximation method; 2) Electrical properties were calculated for both two phases by first-principle calculation; 3) Power factor and ZT were calculated by combining thermal conductivity and electrical properties.
3. The collaborative research on phonon properties and thermal conductivity benchmark: 1) Phonon properties and thermal conductivity were calculated for one of five materials by ALAMODE package; 2) The calculation was refined after comparing the results of this material from all participants using the same calculation package; 3) The calculation of phonon properties and thermal conductivity were started for other two of five materials.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
1: 当初の計画以上に進展している
理由
1. The references were searched and read to learn more about the research background and status.
2. The first-principle calculation with VASP based on density functional theory, the thermal properties calculation with ALAMODE based on relaxation time approximation, and the structure prediction with Monte Carlo simulation and cluster expansion were studied.
3. Three works have been conducted with good progress described as follows. 1) The research on thermoelectric performance of ternary alloys based on structure prediction: Cluster expansion was constructed based on the database composed of results from first-principle calculations; Lattice structures were predited by Monte Carlo simulations and cluster expansion; Thermal conductivity, electrical properties, and ZT were calculated for alloys of different compositions. 2) The research on thermoelectric performance of nanostructured multiphase material: Thermal conductivity were calculated for both two phases based on relaxation time approximation method; Electrical properties were calculated for both two phases by first-principles calculation; Power factor and ZT were calculated for both two phases. 3) The collaborative research on phonon properties and thermal conductivity benchmark: Phonon properties and thermal conductivity were calculated for one of five materials with ALAMODE package; The calculation was refined by comparing the results from all participants using the same calculation package; The calculation of phonon properties and thermal conductivity were started for other two of five materials.
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| 今後の研究の推進方策 |
The plans containing three works are described below.
1. The study on thermoelectric performance of ternary alloys based on structure prediction: 1) To study the dependence of thermal conductivity, electrical properties and ZT on different compositions by relaxation time approximation method and first-principle calculation; 2) To compare the calculated thermal conductivity, electrical properties and ZT with experimental results; 3) To analyze the reason for the dependence on alloy composition and reveal the physical mechanisms; 4) To summarize the results into a manuscript for publication.
2. The study on thermoelectric performance of nanostructured multiphase material: 1) To refine the first-principle calculation by performing GW calculation to obtain more resonable and accurate electrical properties, especially for band structure and density of states; 2) To improve ZT with decreased thermal conductivity by introducing nanostructures into both two phases; 3) To analyze the reason for the differences of ZT between two phases and reveal the physical mechanisms; 4) To summarize the results into a manuscript for publication.
3. The collaborative research on phonon properties and thermal conductivity benchmark: 1) To calculate phonon properties and thermal conductivity for other four of five materials; 2) To refine the calculation and establish the best practice after comparing the results from all participants; 3) To benchmark three of the most popular open-source packages for the community moving forward; 4) To summarize the results into a manuscript for publication.
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