Evidence of tuned anharmonicity in the thermoelectric material Cu2-x S
Abstract The mechanisms underlying the low thermal conductivity of Cu2-x (S, Se) have been attracting considerable attention. However, Cu defects in Cu2-x (S, Se) have been reported to lead to an unusual increase in lattice thermal conductivity, unlike the typical decrease caused by phonon scatterin...
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| Format: | Article |
| Language: | English |
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Nature Portfolio
2025-04-01
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| Series: | Communications Materials |
| Online Access: | https://doi.org/10.1038/s43246-025-00775-6 |
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| _version_ | 1849700074588733440 |
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| author | Seungyub Song Takashi Saito Sanghyun Lee Masato Hagihala Yoshihisa Ishikawa Shuki Torii Kazuhiro Mori Shinichi Itoh Kug-Seung Lee Deok-Yong Cho Takashi Kamiyama |
| author_facet | Seungyub Song Takashi Saito Sanghyun Lee Masato Hagihala Yoshihisa Ishikawa Shuki Torii Kazuhiro Mori Shinichi Itoh Kug-Seung Lee Deok-Yong Cho Takashi Kamiyama |
| author_sort | Seungyub Song |
| collection | DOAJ |
| description | Abstract The mechanisms underlying the low thermal conductivity of Cu2-x (S, Se) have been attracting considerable attention. However, Cu defects in Cu2-x (S, Se) have been reported to lead to an unusual increase in lattice thermal conductivity, unlike the typical decrease caused by phonon scattering induced by point defects. We propose that this anomaly is caused by atomic anharmonicity. Here, we perform neutron diffraction on Cu defect-controlled Cu2-x S to reveal that as Cu defects increase, the volume of tetrahedral Cu distribution significantly shrinks and centralizes, suggesting a change in the potential around the Cu atom. We find that the degree of anharmonicity is highest in Cu2S and decreases with increasing Cu defects using one-particle potential fitting. This trend explains the increase in lattice thermal conductivity with increasing Cu defects. Our findings show that anharmonicity can be tuned through Cu defects, explaining the underlying mechanism of the anomalous increase in the lattice thermal conductivity. |
| format | Article |
| id | doaj-art-ded50828a6754e3381ceea27fef0e382 |
| institution | DOAJ |
| issn | 2662-4443 |
| language | English |
| publishDate | 2025-04-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Communications Materials |
| spelling | doaj-art-ded50828a6754e3381ceea27fef0e3822025-08-20T03:18:23ZengNature PortfolioCommunications Materials2662-44432025-04-01611810.1038/s43246-025-00775-6Evidence of tuned anharmonicity in the thermoelectric material Cu2-x SSeungyub Song0Takashi Saito1Sanghyun Lee2Masato Hagihala3Yoshihisa Ishikawa4Shuki Torii5Kazuhiro Mori6Shinichi Itoh7Kug-Seung Lee8Deok-Yong Cho9Takashi Kamiyama10Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK)Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK)Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK)Materials Sciences Research Center, Japan Atomic Energy AgencyNeutron Science and Technology Center, Comprehensive Research Organization for Science and SocietyInstitute of Materials Structure Science, High Energy Accelerator Research Organization (KEK)Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK)Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK)Pohang Accelerator Laboratory, POSTECHDepartment of Physics, Jeonbuk National UniversityInstitute of Materials Structure Science, High Energy Accelerator Research Organization (KEK)Abstract The mechanisms underlying the low thermal conductivity of Cu2-x (S, Se) have been attracting considerable attention. However, Cu defects in Cu2-x (S, Se) have been reported to lead to an unusual increase in lattice thermal conductivity, unlike the typical decrease caused by phonon scattering induced by point defects. We propose that this anomaly is caused by atomic anharmonicity. Here, we perform neutron diffraction on Cu defect-controlled Cu2-x S to reveal that as Cu defects increase, the volume of tetrahedral Cu distribution significantly shrinks and centralizes, suggesting a change in the potential around the Cu atom. We find that the degree of anharmonicity is highest in Cu2S and decreases with increasing Cu defects using one-particle potential fitting. This trend explains the increase in lattice thermal conductivity with increasing Cu defects. Our findings show that anharmonicity can be tuned through Cu defects, explaining the underlying mechanism of the anomalous increase in the lattice thermal conductivity.https://doi.org/10.1038/s43246-025-00775-6 |
| spellingShingle | Seungyub Song Takashi Saito Sanghyun Lee Masato Hagihala Yoshihisa Ishikawa Shuki Torii Kazuhiro Mori Shinichi Itoh Kug-Seung Lee Deok-Yong Cho Takashi Kamiyama Evidence of tuned anharmonicity in the thermoelectric material Cu2-x S Communications Materials |
| title | Evidence of tuned anharmonicity in the thermoelectric material Cu2-x S |
| title_full | Evidence of tuned anharmonicity in the thermoelectric material Cu2-x S |
| title_fullStr | Evidence of tuned anharmonicity in the thermoelectric material Cu2-x S |
| title_full_unstemmed | Evidence of tuned anharmonicity in the thermoelectric material Cu2-x S |
| title_short | Evidence of tuned anharmonicity in the thermoelectric material Cu2-x S |
| title_sort | evidence of tuned anharmonicity in the thermoelectric material cu2 x s |
| url | https://doi.org/10.1038/s43246-025-00775-6 |
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