Researchers Huiju Lee, Zhi Li, Jiangang He, and Yi Xia from the Massachusetts Institute of Technology (MIT) have developed a novel computational framework to study temperature-dependent phonons in inorganic materials. Their work, published in the journal Nature Communications, offers new insights into thermal transport and structural stability, which are crucial for various energy applications.
Phonons, or quantized vibrations of the atomic lattice, play a significant role in determining the thermal and vibrational properties of materials. However, most existing computational models rely on the harmonic approximation, which overlooks essential temperature-dependent anharmonic effects. The MIT team addressed this limitation by combining machine learning interatomic potentials, anharmonic lattice dynamics, and high-throughput calculations.
The researchers fine-tuned the universal M3GNet interatomic potential using high-quality phonon data, improving phonon prediction accuracy by a factor of four while maintaining computational efficiency. They then integrated this refined model into a high-throughput implementation of the stochastic self-consistent harmonic approximation to compute temperature-dependent phonons for 4,669 inorganic compounds.
Their analysis revealed systematic elemental and structural trends governing anharmonic phonon renormalization, with notable effects observed in alkali metals, perovskite-derived frameworks, and related systems. Machine learning models trained on this dataset identified key atomic-scale features driving strong anharmonicity, such as weak bonding, large atomic radii, and specific coordination motifs.
First-principles validation confirmed that anharmonic effects can significantly alter lattice thermal conductivity by factors of two to four in some materials. This work establishes a robust and efficient data-driven approach for predicting finite-temperature phonon behavior, offering new pathways for designing and discovering materials with tailored thermal and vibrational properties.
For the energy sector, this research could lead to the development of materials with optimized thermal transport properties, which are crucial for applications such as thermoelectric energy conversion, thermal barrier coatings, and thermal management in electronic devices. By understanding and controlling phonon behavior, researchers can design materials that enhance energy efficiency and performance in various energy systems.
Source: Lee, H., Li, Z., He, J., & Xia, Y. (2023). Data-Driven Exploration and Insights into Temperature-Dependent Phonons in Inorganic Materials. Nature Communications.
This article is based on research available at arXiv.