Relationship between local coordinates and thermal conductivity in amorphous carbon

To determine the correlation between local structure and thermal conductivity of amorphous carbon, we investigated heat conduction in 216-atom systems with different densities (2.0-3.4 g/cm(3)) using the ab initio molecular dynamics approach. By applying the Allen-Feldman theory with interatomic force constants from ab initio calculations, we report a significant correlation between the thermal conductivity and the density. To clarify which structural characteristics in the high- and low-density cases determine the magnitude of thermal conductivity, we performed geometrical and topological analyses. Coordination number analysis and ring statistics revealed that the sp/sp(2)/sp(3) bond ratios and topological characteristics correlate with density. We also demonstrated that these structural characteristics can be quantified using persistent homology analysis, providing a predictive model of thermal conductivity.& nbsp;& nbsp;(c) 2022 Author(s)

Automated summary

The correlation between local structure and thermal conductivity of amorphous carbon was investigated. It was found that there is a significant correlation between thermal conductivity and density. Geometrical and topological analyses showed that bond ratios and topological characteristics are correlated with density. Persistent homology analysis can be used to quantify these structural characteristics and provide a predictive model of thermal conductivity.