About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
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| Symposium
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Phase Stability, Phase Transformations, and Reactive Phase Formation in Electronic Materials XXV
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| Presentation Title |
Nanograined Multi-Phase Gallium Nitride Through Ultrafast Melt-Quenching: Formation Mechanism and Ultralow Lattice Thermal Conductivity |
| Author(s) |
Mehrab Lotfpour, Haoran Cui, Nolan Hagen, Milad Nasiri, Theodore Maranets, Yan Wang, Lei Cao |
| On-Site Speaker (Planned) |
Mehrab Lotfpour |
| Abstract Scope |
The microstructural evolution and thermal transport properties of gallium nitride (GaN) subjected to ultrafast quenching are investigated using molecular dynamics simulations. Varying cooling rates result in distinct nucleation pathways and the formation of defect-rich microstructures comprising both zincblende (ZB) and wurtzite (WZ) phases, including unique superlattice-like arrangements. The defects discussed in this study include twins, stacking faults, and dislocations. Moreover, different nucleation cores have formed during the quenching process, which has influenced the final microstructure. Additionally, quenched GaN exhibits ultralow thermal conductivity, with reductions up to 99% compared to pristine GaN, primarily due to phonon scattering at grain and phase boundaries. Notably, coherent WZ/ZB interfaces maintain high thermal conductance owing to efficient phonon mode matching. These findings offer atomistic insights for engineering heat conduction in GaN through controlled microstructural design. |
| Proceedings Inclusion? |
Planned: |