Enhancement of structural, linear and non-linear optical properties of Ti1−xCa2xO2 solid solutions

Abstract

Structural and morphological analyses of the Ti1−xCa2xO2 solid solutions and their complete linear and non-linear optical properties were investigated. Ti1−xCa2xO2 (0≤ x ≤0.5) powders were successfully synthesized via solid-state reaction route. The XRD patterns confirmed that the pure and doped samples exhibited anatase TiO2 phase. The crystallite size of TiO2 decreased to 82 nm after Ca doping. Furthermore, the dislocation density and lattice deformation are increased with increasing calcium concentration. SEM analysis revealed that Ti1−xCa2xO2 (0≤ x ≤0.5) powders have a granular structure and with doping, atom aggregations take on softer shapes. Energy dispersive x-ray Analysis (EDX) showed the appropriate composition for the ions depicted in the structure. Using spectrophotometric data, linear and non-linear optical parameters were obtained and associated with the Ca content. The band gap of TiO2 has shifted from 3.11 to 2.8 eV with dopant concentration. As the percentage of Ca increased, the dielectric constant and optical conductivity also increased. The dispersion energy, plasma frequency, non-linear refractive index and Sellmeier’s parameters were also calculated and discussed with respect to Ca doping. The optical results obtained revealed the potential of the Ti1−xCa2xO2 (0≤ x ≤0.5) samples for optical and optoelectronic applications.