Structural, Electronic and Optical Properties of Cubic CaCu3Ti_4–xAg_xO₁₂ Perovskite Ceramics: A First-Principles Study

Abstract

The Structural, electronic and optical properties of cubic CaCu3Ti4-xAgxO12 (x = 0, 0.5, 1, 1.5 and 2) perovskite ceramics have been investigated by the first principle method. The CaCu3Ti4-xAgxO12 ceramics still maintains the bcc lattice and the lattice constants increase with the increasing Ag concentration. The formation energies of the CaCu3Ti4-xAgxO12 ceramics are all negative, which indicates that the crystal structures of all ceramics are thermodynamically stable. Pure CaCu3Ti4O12 ceramic has semiconductor properties, and the spin up and spin down energy band gaps of cubic CaCu3Ti4O12 ceramic at the high symmetry point Γ are 1.1891eV and 0.8527eV, respectively. After doping silver, however, the CaCu3Ti4-xAgxO12 ceramics show metallic properties. The optical properties such as dielectric function, reflectivity, refractive index, photoconductivity, extinction coefficient, absorption coefficient and energy loss function are also discussed.

Keywords

• CaCu₃Ti₄O₁₄ceramic
• Ag doping
• structural properties
• electronic properties
• optical properties
• first-principles