Akademik Veri Yönetim Sistemi
Physica Scripta, cilt.100, sa.3, 2025 (SCI-Expanded)
First-principles calculations were performed to systematically study RVO4 orthovanadates with tetragonal zircon- and scheelite-type structures. The study focused on structural parameters, pressure-induced structural phase transformation, electronic band structure, and optical properties under ambient conditions and hydrostatic pressures up to 10 GPa. Energy-volume and enthalpy-pressure curves were used to determine the phase transition pressures of RVO4 compounds. Among the four compounds examined in both phases, YbVO4 was determined to be less compressible than the other compounds. The computed band structures indicated that RVO4 compounds in both phases are semiconductors with a direct bandgap at the Γ→ Γ point. Optical spectra such as dielectric constants, refractive index, reflectivity, absorption coefficient, birefringence, optical conductivity, and energy loss function were computed as functions of incident radiation energy in the energy range of 0-45 eV. The optical anisotropy of RVO4 compounds was observed in both phases. The computed birefringence values for zircon (scheelite) RVO4 indicate that they are uniaxial positive (negative) crystals and have a large birefringence value. Hydrostatic pressure was found to play an important role in the structural, optical, and electronic properties of both phases of RVO4 compounds.