English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Amorphous silica (a-SiO$_2$) is a foundational disordered material for whichthe thermal transport properties are important for various applications. Toaccurately model the interatomic interactions in classical molecular dynamics(MD) simulations of thermal transport in a-SiO$_2$, we herein develop anaccurate yet highly efficient machine-learned potential model that allowed usto generate a-SiO$_2$ samples closely resembling experimentally produced ones.Using the homogeneous nonequilibrium MD method and a proper quantum-statisticalcorrection to the classical MD results, quantitative agreement with experimentsis achieved for the thermal conductivities of bulk and 190 nm-thick a-SiO$_2$films over a wide range of temperatures. To interrogate the thermal vibrationsat different temperatures, we calculated the current correlation functionscorresponding to the transverse acoustic (TA) and longitudinal acoustic (LA)collective vibrations. The results reveal that below the Ioffe-Regel crossoverfrequency, phonons as well-defined excitations, remain applicable in a-SiO$_2$and play a predominant role at low temperatures, resulting in atemperature-dependent increase in thermal conductivity. In the high-temperatureregion, more phonons are excited, accompanied by a more intense liquid-likediffusion event. We attribute the temperature-independent thermal conductivityin the high-temperature range of a-SiO$_2$ to the collaborative involvement ofexcited phonon scattering and liquid-like diffusion in heat conduction. Thesefindings provide physical insights into the thermal transport of a-SiO$_2$ andare expected to be applied to a vast range of amorphous materials.

Mechanisms of temperature-dependent thermal transport in amorphous silica from machine-learning molecular dynamics