| About this Abstract |
| Meeting |
2025 TMS Annual Meeting & Exhibition
|
| Symposium
|
Innovations in Energy Materials: Unveiling Future Possibilities of Computational Modelling and Atomically Controlled Experiments
|
| Presentation Title |
Structure Low Dimensionality and Lone-Pair Stereochemical Activity: the Key to Low Thermal Conductivity in sulfides |
| Author(s) |
Emmanuel Guilmeau |
| On-Site Speaker (Planned) |
Emmanuel Guilmeau |
| Abstract Scope |
Recently, metal sulfides have begun to receive attention as potential
cost-effective materials for thermoelectric applications beyond optoelectronic and
photovoltaic devices. Herein, based on a comparative analysis of the structural and
transport properties of lone-pair cation-based sulfides, we demonstrate that the
intrinsic effects that govern the low lattice thermal conductivity (KL) of these
sulfides originate from the combination of the low dimensionality of their crystal
structures with the stereochemical activity of the lone-pair electrons of cations.
The presence of weak bonds in these materials, associated in some cases with rattling phenomena or static disorder, strongly enhance phonon scattering. First-principles density functional theory calculations reveal that the presence of antibonding states below the Fermi level contributes to the very low KL of lone-pair cation-based sulfides. In addition, the calculated phonon dispersions can exhibit very soft acoustic phonon branches that give rise to soft lattices and very low speeds of sounds. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Energy Conversion and Storage, Computational Materials Science & Engineering, Ceramics |