STUDY OF MICROSTRUCTURAL TRANSFORMATION DEPEND ON PRESSURE BY LARGE MODEL OF LIQUID SILICA

Abstract

Microstructure of liquid silica under densification by large model which consists 19998 atomics at the temperature of  3500 K and in the 0÷45 GPa pressure ranges was studied by molecular dynamics simulation. The results of analysis partial radial distribution function, distribution bond angle and the distributions of partial units have shown that: the geometric structure of the units, as well as the short-range order, has not changed significantly, while the proportion of units and intermediate -range order have changed significantly. At any pressure, liquid SiO₂ always exists low density and high density phases. The low density phase created by the SiO₄ units is linked together via OSi₂. The high density phase created by the SiO₅ and SiO₆ units is linked together via OSi₃.