Band engineering and phonon softening enable the achievement of significant enhancement in the thermoelectric performance of EuMg2Sb2 by Zn doping
The Zintl compound EuMg2Sb2 is a promising thermoelectric material due to its inherently low lattice thermal conductivity and tunable electronic and thermal properties related to its multi-component nature. However, the large difference in electronegativity between Mg and Sb results in poor electron...
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| Language: | English |
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Elsevier
2025-05-01
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| Series: | Journal of Materiomics |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2352847824001497 |
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| author | Qingzhi Song Linyu Bai Xi Gao Lei Wei Xian Zhao Yanlu Li |
| author_facet | Qingzhi Song Linyu Bai Xi Gao Lei Wei Xian Zhao Yanlu Li |
| author_sort | Qingzhi Song |
| collection | DOAJ |
| description | The Zintl compound EuMg2Sb2 is a promising thermoelectric material due to its inherently low lattice thermal conductivity and tunable electronic and thermal properties related to its multi-component nature. However, the large difference in electronegativity between Mg and Sb results in poor electronic transport properties, reducing its thermoelectric conversion efficiency and limiting its practical application. Thus, this study investigates a doping modification strategy for enhancing the thermoelectric performance of EuMg2Sb2 and the microscopic mechanism using the first-principle calculations combined with the Boltzmann transport theory. Indeed, the larger energy separation at the valence band maximum is the key factor affecting the electronic transport properties of EuMg2Sb2. The results demonstrate that Zn doping at the Mg site effectively increases the thermoelectric performance by promoting the valence band convergence owing to the close electronegativity to Sb and softening the phonon thus largely suppressing the lattice thermal conductivity. By optimizing the Zn doping concentration, the highest figure of merit (zT) value is significantly increased to 2.24 (2.66) in the x (z) direction at 800 K. The results suggest that the proposed modulation strategy and effect are of great significance for improving the thermoelectric performance of Zintl materials. |
| format | Article |
| id | doaj-art-d2b6d2d53cc54dd0b045f1b31bde0fd6 |
| institution | DOAJ |
| issn | 2352-8478 |
| language | English |
| publishDate | 2025-05-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Materiomics |
| spelling | doaj-art-d2b6d2d53cc54dd0b045f1b31bde0fd62025-08-20T02:47:10ZengElsevierJournal of Materiomics2352-84782025-05-0111310091010.1016/j.jmat.2024.06.007Band engineering and phonon softening enable the achievement of significant enhancement in the thermoelectric performance of EuMg2Sb2 by Zn dopingQingzhi Song0Linyu Bai1Xi Gao2Lei Wei3Xian Zhao4Yanlu Li5State Key Lab of Crystal Materials and Institute of Crystal Materials, Shandong University, Jinan, 250100, ChinaState Key Lab of Crystal Materials and Institute of Crystal Materials, Shandong University, Jinan, 250100, ChinaState Key Lab of Crystal Materials and Institute of Crystal Materials, Shandong University, Jinan, 250100, ChinaInspur Intelligent Terminal Co. Ltd, Inspur Group, Jinan, 250000, China; Jinan Key Laboratory of Metal-Based Thermal Functional Materials and Technology, Inspur Group, Jinan, 250000, China; Corresponding author. Inspur Intelligent Terminal Co. Ltd, Inspur Group, Jinan, 250000, China.Center for Optics Research and Engineering of Shandong University, Shandong University, Qingdao, 266237, ChinaState Key Lab of Crystal Materials and Institute of Crystal Materials, Shandong University, Jinan, 250100, China; Corresponding author.The Zintl compound EuMg2Sb2 is a promising thermoelectric material due to its inherently low lattice thermal conductivity and tunable electronic and thermal properties related to its multi-component nature. However, the large difference in electronegativity between Mg and Sb results in poor electronic transport properties, reducing its thermoelectric conversion efficiency and limiting its practical application. Thus, this study investigates a doping modification strategy for enhancing the thermoelectric performance of EuMg2Sb2 and the microscopic mechanism using the first-principle calculations combined with the Boltzmann transport theory. Indeed, the larger energy separation at the valence band maximum is the key factor affecting the electronic transport properties of EuMg2Sb2. The results demonstrate that Zn doping at the Mg site effectively increases the thermoelectric performance by promoting the valence band convergence owing to the close electronegativity to Sb and softening the phonon thus largely suppressing the lattice thermal conductivity. By optimizing the Zn doping concentration, the highest figure of merit (zT) value is significantly increased to 2.24 (2.66) in the x (z) direction at 800 K. The results suggest that the proposed modulation strategy and effect are of great significance for improving the thermoelectric performance of Zintl materials.http://www.sciencedirect.com/science/article/pii/S2352847824001497ThermoelectricEuMg2Sb2Band engineeringPhonon softeningFirst-principles |
| spellingShingle | Qingzhi Song Linyu Bai Xi Gao Lei Wei Xian Zhao Yanlu Li Band engineering and phonon softening enable the achievement of significant enhancement in the thermoelectric performance of EuMg2Sb2 by Zn doping Journal of Materiomics Thermoelectric EuMg2Sb2 Band engineering Phonon softening First-principles |
| title | Band engineering and phonon softening enable the achievement of significant enhancement in the thermoelectric performance of EuMg2Sb2 by Zn doping |
| title_full | Band engineering and phonon softening enable the achievement of significant enhancement in the thermoelectric performance of EuMg2Sb2 by Zn doping |
| title_fullStr | Band engineering and phonon softening enable the achievement of significant enhancement in the thermoelectric performance of EuMg2Sb2 by Zn doping |
| title_full_unstemmed | Band engineering and phonon softening enable the achievement of significant enhancement in the thermoelectric performance of EuMg2Sb2 by Zn doping |
| title_short | Band engineering and phonon softening enable the achievement of significant enhancement in the thermoelectric performance of EuMg2Sb2 by Zn doping |
| title_sort | band engineering and phonon softening enable the achievement of significant enhancement in the thermoelectric performance of eumg2sb2 by zn doping |
| topic | Thermoelectric EuMg2Sb2 Band engineering Phonon softening First-principles |
| url | http://www.sciencedirect.com/science/article/pii/S2352847824001497 |
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