Frequency Dependent Specific Heat of Amorphous Silica: A Molecular Dynamics Computer Simulation

TL;DR

This study uses molecular dynamics simulations to analyze how the specific heat of amorphous silica varies with frequency, revealing characteristic peaks that shift with temperature, enhancing understanding of silica's thermal properties.

Contribution

It introduces a detailed simulation approach to examine the frequency-dependent specific heat of amorphous silica, highlighting the relationship between microscopic dynamics and thermal response.

Findings

High-frequency microscopic peak observed in specific heat.

Alpha-peak shifts to lower frequencies with decreasing temperature.

Frequency dependence mirrors structural quantity behavior.

Abstract

We use molecular dynamics computer simulations to calculate the frequency dependence of the specific heat of a SiO_2 melt. The ions interact with the BKS potential and the simulations are done in the NVE ensemble. We find that the frequency dependence of the specific heat shows qualitatively the same behavior as the one of structural quantities, in that at high frequencies a microscopic peak is observed and at low frequencies an alpha-peak, the location of which quickly moves to lower frequencies when the temperature is decreased.