Statistical mechanical study of thermodynamic properties of a family of fullerites from C36 to C96 in the equilibrium with their vapors

TL;DR

This study uses a statistical mechanical approach to analyze the thermodynamic properties and vapor pressures of fullerites from C36 to C96, considering anharmonic lattice vibrations and comparing with experimental data.

Contribution

It introduces a detailed theoretical calculation of fullerites' thermodynamic properties using an advanced self-consistent field method and updated intermolecular potentials.

Findings

Calculated vapor pressures match experimental data.

Thermodynamic properties vary systematically with molecule size.

Identified stability limits for different fullerites.

Abstract

On the basis of the correlative method of the unsymmetrized self-consistent field that yields the account of the strong anharmonicity of the lattice vibrations, it has been calculated the temperature dependence of saturated vapor pressure of higher and smaller fullerites, from C36 up to the C96, and their thermodynamic properties along their sublimation curves. We have used the intermolecular potential of Girifalco with parameters recently calculated for these fullerenes. The calculations were accomplished up to the temperature of loss of stability (spinodal point) Ts. We compare our results with available experimental data, and with quantities calculated earlier for the magnitudes of the most widespread of the fullerites, the C60. The behavior of some characteristics is considered in their dependence on the number of atoms in the molecule.