KMS Chongqing Institute of Green and Intelligent Technology, CAS
| Abnormally Low Lattice Thermal Conductivity in ABX Honeycomb Compounds | |
Zhou, Z. Z.1; Peng, K. L.1,2,3; Fu, H. X.1; Wu, H.1; Wang, G. Y.4; Zhou, X. Y.1
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| 2021-12-14 | |
| 摘要 | Planar structure and small atomic mass usually induce high lattice thermal conductivity in a crystalline solid. Here, we present a first-principles study on the lattice dynamics and phonon-transport properties of a series of ABX honeycomb compounds and show that replacing cations with lighter atoms may yield lower lattice thermal conductivity (Kl). The anomalous mass-trend Kl, which is experimentally observed, is found to be inherent to the lattice vibration of the specific layered honeycomb structure, using ACuSb (A = Ca, Sr, and Ba) as prototypical compounds. We reveal that a lighter A atom bonds more weakly with the Cu-Sb honeycomb ring, giving rise to stronger vibrational anharmonicity, which induces ultralow Kl in CaCuSb that is unexpected of light elements and a high-symmetry planar structure. Combined with the high degeneracy and strong anisotropy of the bottom conduction band, CaCuSb exposes an ultrahigh n-type zT of about 2.2 at 700 K. These findings elucidate the mechanism governing anomalous phonontransport behavior, which also offers guidance in discovering low-cost and low-mass-density materials for advanced thermoelectric applications. |
| DOI | 10.1103/PhysRevApplied.16.064034 |
| 发表期刊 | PHYSICAL REVIEW APPLIED
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| ISSN | 2331-7019 |
| 卷号 | 16期号:6页码:9 |
| 通讯作者 | Zhou, X. Y.(xiaoyuan2013@cqu.edu.cn) |
| 收录类别 | SCI |
| WOS记录号 | WOS:000732552500001 |
| 语种 | 英语 |
