Thermo-physical Properties of ThC and ThN from First Principles
Thorium carbide and nitride are potential candidates for their use as fuel materials in fast breeder reactors. Therefore, knowledge of their thermo-physical properties at high temperatures is necessary. In this paper, we present results of the first-principle calculations of properties such as specific heat, volume and bulk modulus at high temperatures. The all-electron FPLAPW method has been used with LDA, GGA, LDA+U and GGA+U exchange–correlation potentials for performing these calculations. It has been found that GGA gives the most accurate ground state properties such as lattice constant, bulk modulus and pressure derivative of the bulk modulus. Therefore, first principles results obtained from GGA calculations have been combined with quasi-harmonic approximations to calculate the thermo-physical properties. Calculated thermo-physical properties are in reasonably good agreement with published experimental results.
KeywordsThorium carbide Thorium nitride Specific heat High-temperature bulk modulus FPLAPW
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