Bond-network entropy governs heat transport in coordination-disordered solids

Understanding how the vibrational and thermal properties of solids are influenced by atomistic structural disorder is of fundamental scientific interest, and paramount to designing materials for next-generation energy technologies. While several studies indicate that structural disorder strongly influences the thermal conductivity, the fundamental physics governing the disorder-conductivity relation remains elusive. Here we show that order-of-magnitude, disorder-induced variations of conductivity in network solids can be predicted from a bond-network entropy, an atomistic structural descriptor that quantifies heterogeneity in the topology of the atomic-bond network. We employ the Wigner formulation of thermal transport to demonstrate the existence of a relation between the bond-network entropy, and observables such as smoothness of the vibrational density of states (VDOS) and macroscopic conductivity. We also show that the smoothing of the VDOS encodes information about the thermal resistance induced by disorder, and can be directly related to phenomenological models for phonon-disorder scattering based on the semiclassical Peierls-Boltzmann equation. Our findings rationalize the conductivity variations of disordered carbon polymorphs ranging from nanoporous electrodes to defective graphite used as a moderator in nuclear reactors.
This database contains the models of structures reported in the paper referenced below.

厘清原子尺度结构无序如何影响固体的振动与热学性质，兼具基础科学研究价值与下一代能源技术材料设计的核心指导意义。尽管已有多项研究表明结构无序会显著影响热导率，但调控无序与热导率之间关联的基础物理机制仍不明晰。本研究表明，网状固体中由无序诱导产生的热导率数量级差异，可通过键网络熵（bond-network entropy）进行预测——该原子尺度结构表征量可量化原子键合网络拓扑结构的异质性。本研究采用热输运的维格纳（Wigner）表述，证明了键网络熵与若干可观测物理量之间存在关联，这些可观测物理量包括振动态密度（vibrational density of states, VDOS）的平滑程度以及宏观热导率。此外，本研究发现振动态密度的平滑程度携带着无序诱导产生的热阻相关信息，且可与基于半经典皮埃尔斯-玻尔兹曼（Peierls-Boltzmann）方程的声子-无序散射唯象模型直接建立关联。本研究结果可合理解释从纳米多孔电极到核反应堆慢化剂用缺陷石墨等各类无序碳同素异形体的热导率变化规律。
本数据集包含下述参考文献论文中报道的结构模型。