Volume 12

Molecular Dynamics Study of the Structural and Thermodynamic Properties of Sio2 Silica During Cooling Between 5000 and 300k
  • Alain DZABANA HONGUELET1,2,4, Georges Désiré BIDILOU 2,4,5, Charlemagne Franklin MOUSSOKI2,4,5 and Timothée NSONGO1,2,3, 1Marien Ngouabi University, Congo Brazzaville, 2Research Group on Physical and Chemical Properties of Materials, Congo Brazzaville, 3Geological and Mining Research Center, Congo Brazzaville, 4Association Alpha Sciences Beta Technologies, Congo Brazzaville, 5Ecole Normale Supérieure, Congo Brazzaville

    Abstract

    In this work we observed the evolution of the structural and thermodynamic properties of silica during cooling in a temperature range from 5000 to 300K by the LAMMPS computational code. The structure 𝑆𝑖𝑂2used in this work was obtained from the Materials Project database, containing 144 atoms and with mesh parameters a=b=19.607A° and c=7.496 A° and density 1.66. The results were obtained with the use of MEAM and Buckingham potentials reflecting respectively the nature of the alloy and the effect of the SiO silica charge2. However the particularity was observed for the MEAM potential presenting a point around 4376.22K, with a volume of V=2776.242A°3 , mesh parameter Lx=19.362A° and a density =1.725. For the thermodynamic properties, we showed that the enthalpy decreased with temperature; for the interval from 5000 to 3000K we observed a random distribution of the enthalpy, this distribution was more precise for temperatures between 2000 and 300K; however the specific heat presented an average trend around 6j/(K*mol).

    Keywords

    Silica, SiO2, MEAM potential, Buckingham potential, cooling, enthalpy, specific heat, molecular dynamics.

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