Modeling lattice heat-capacity contributions by a single-parametric phonon dispersion approach

• Published in: The Journal of chemical thermodynamics 1997-03, Vol.29 (3), p.311-336
• Main Authors: Komada, Norikazu, Westrum, Jr, Edgar F.
• Format: Article
• Language: English
• Subjects: characteristic temperatures; Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; excess properties; Lattice dynamics; lattice heat capacity; modelingCp; phonon distribution; Phonon states and bands, normal modes, and phonon dispersion; Phonons and vibrations in crystal lattices; Physics; Thermal properties of condensed matter; Thermal properties of crystalline solids
• ISSN: 0021-9614; 1096-3626
• DOI: 10.1006/jcht.1996.0159

A new phonon distribution model was developed to provide a precise and reliable equation for lattice heat capacity at constant volume,e.g.for the resolution of excess thermophysical properties. Because this equation has a single characteristic temperature as a parameter determined after assignment of the other parameters available from chemical, crystallographical and/or elastic information, it is relatively easy to fit the model to the experimental heat-capacity data. It is based on the harmonic oscillator model and, therefore, may require adjustment at high sub-ambient temperatures or super-ambient regions. Three FORTRAN IV computer programs provide convenient devices to calculate the apparent characteristic temperatures from given heat-capacity values, to calculate lattice heat-capacity values for given characteristic temperatures, and to compare the (model) predicted heat capacity with experimental heat-capacity values.