Investigation of Computational Determination of Elastic Properties for Silicon Nitride and Silicon Carbonitride Materials

Abstract

Silicon nitride and silicon carbonitride materials are versatile materials exhibiting useful properties at high temperatures and pressures. This study investigates the use of molecular dynamics simulations to determine the elastic properties of these materials. Elastic constants and moduli are determined for a series of crystalline and amorphous silicon nitride materials and amorphous silicon carbonitride materials employing Tersoff, Garofalini, and Marian-Gastreich two-body empirical potentials. Our results show that the Tersoff empirical potential is best suited of the three under study to elastic property determination. Results also show that the elastic behavior of silicon carbonitride is highly dependent on the morphology of carbon in the material. This study shows that there is a need for an empirical potential which accurately captures the elastic behavior of these materials at high temperature.