Electronic and optical properties of rare earth tetraborides RB4 (R=ND, TB, DY, and ER): First-principles calculations

The electronic structures and optical properties of tetraborides RB4 (R=Nd, Tb, Dy, and Er) are systematically investigated through the first-principles technique. The band structure and density of states (DOS) show that RM4 has metal and magnetic characteristics. The DOS near the Fermi is dominated by R-4f states, which are responsible for the magnetic moments. The optical properties including refractive index, conductivity, absorptivity, reflectivity, and loss function are obtained based on the complex dielectric functions. The static dielectric constants and static refractive are presented. The absorptivity results indicate that tetraborides exhibit excellent optical absorption in the ultraviolet-visible (UV-Vis) regions. The reflectivity shows that RB4 is an ideal near-infrared reflective material. This study provides theoretical insights into the optical applications of tetraborides.