First principles study of ceramic materials (IVB group carbides) under ultrafast laser irradiation

Abstract

Group IVB carbides have been applied in extreme aerospace environments as hard ceramic coatings; ZrC is being considered as a replacement for SiC in nuclear reactors. Therefore, a thorough understanding of the laser irradiation response of group IVB carbides is of clear significance. However, the existing knowledge on the fundamental properties of IVB group carbides is limited and insufficient with regard to both irradiated and non-irradiated characteristics. We investigate the effect of ultrafast laser irradiation on the lattice stability of ceramic materials (IVB group carbides) using the density functional perturbation theory (DFPT). The calculated phonon frequencies of TiC and ZrC at the ground state are in good agreement with previous calculations and experimental values. The phonon frequencies of IVB group carbides are positive, even though the electronic temperature reached 5 eV. Thus, IVB group carbides are more stable under ultrafast laser irradiation, which has greater benefits in nuclear and aeronautical applications compared to metals (W, Na), semimetals (Bi), and semiconductors (Si, SiC). The thermodynamic properties of ZrC are calculated as functions of their lattice temperature at different electronic temperatures. The elastic shear constants of IVB group carbides satisfy the Born stability criteria at T e = 5 eV. In addition, a comparison of the predicted melting temperatures of IVB group carbides, reveal that HfC is better suited for extreme high-temperature environments.

Characterization of a Li4TiO4 Tritium Breeder by First-Principles Calculation and an Experimental Approach

“…Computational Details. The calculation method presented in this paper is accomplished with the Vienna Ab initio Simulation Package (VASP), 8,27,28 which is based on first-principles density functional theory. 29 The projector augment wave (PAW) pseudopotential is used to explain the mutual effect of ions and electrons.…”

“…The calculation method presented in this paper is accomplished with the Vienna Ab initio Simulation Package (VASP), ,, which is based on first-principles density functional theory . The projector augment wave (PAW) pseudopotential is used to explain the mutual effect of ions and electrons. , The Perdew–Wang scheme (PW91) exchange–correlation function of the generalized gradient approximation is implemented for electron exchange correlation .…”