2024 - Sustainable Industrial Processing Summit
SIPS 2024 Volume 4. Kanatzidis Intl. Symp / Solid State Chemistry and Materials
| Editors: | F. Kongoli, M.A. Alario-Franco, I. Chung, M. Delferro, O. Farha, H. Kageyama, F. Marquis, A. Navrotsky, A. Tressaud, P. Trikalitis |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2024 |
| Pages: | 222 pages |
| ISBN: | 978-1-998384-10-5 (CD) |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
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GIANT BIREFRINGENCE ACHIEVED VIA HYDROGEN BOND-CLICK REACTION FOR ENHANCED COPLANARITY LONG-RANGE ANION CORRELATIONS MEDIATING DYNAMIC ANHARMONICITY AND CONTRIBUTING TO GLASSY THERMAL CONDUCTIVITY IN WELL-ORDERED K2Ag4Se3
Li-Ming Wu1;1BEIJING NORMAL UNIVERSITY, Beijing, China;
Type of Paper: Invited
Id Paper: 448
Topic: 52
Abstract:
The realization of ultralow thermal conductivity in a well-ordered structure is crucial for crystalline materials which consider heat conduction properties to be primary in design. We report herein an extremely low (0.32‒0.25 Wm-1K-1) and glassy temperature dependence (300‒600 K) of lattice thermal conductivity in a monoclinic K2Ag4Se3. By applying a unified theory of thermal transport, we reveal that K2Ag4Se3 features a complex phonon scattering mechanism. Delocalized vibrational correlations lead to synergistic inhibition of both propagating and wave-like heat conduction through polarization transmission. Density functional theory calculations reveal that long-range correlated Se vibrations, enhanced by delocalized hole carriers, promote interlayer lattice shearing. This shearing induces dynamically competitive expressions of different orders of anharmonicity, ultimately leading to full-spectrum phonon bunching as the temperature increases. These correlated interactions cause Se anions to vibrate together as a cluster in the low frequency region, resulting in short phonon lifetimes, low group velocities, and a large scattering phase space, which ultimately suppresses both intra- and inter-band phonon transfers. Moreover, these findings have been experimentally confirmed through low-temperature heat capacity measurements and in situ Raman spectroscopy. The insights gained from this work will advance the design of crystalline materials with tailored thermal properties.