Electronic, optical and thermal properties of Cr3AlB4 by first-principles calculations

The electronic, optical and thermal properties of Cr3AlB4 were investigated by using the all-electron projector augmented wave method with the Perdew-Burke Ernzerhof functional. The analysis of band structure and density of states confirms the metallic character of Cr3AlB4. The analysis of normalized total phonons density of states and atomic projected density of states shows that the contributions of B and Cr atoms to the phonon-dispersion structures are larger than that of Al atom. Cr3AlB4 becomes transparent above 23 eV and possesses high reflectivity in the infrared-visible -UV range up to ∼19.76 eV. When the photon energy is bigger than 19.76 eV, the reflectivity sharply decreases to very low reflectivity (high transparency) for short wavelength. The thermal properties were further investigated with the increasing temperature and pressure by using the quasi-harmonic Debye model.