Enhancement of structural, linear and non-linear optical properties of Ti <sub>1−x</sub> Ca <sub>2x</sub> O <sub>2</sub> solid solutions
Sara Ezairi, A. Elouafi, Fatima Lmai, Abdesslam Tizliouine
Abstract
Abstract Structural and morphological analyses of the Ti 1−x Ca 2x O 2 solid solutions and their complete linear and non-linear optical properties were investigated. Ti 1−x Ca 2x O 2 (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 TiO 2 phase. The crystallite size of TiO 2 decreased to 82 nm after Ca doping. Furthermore, the dislocation density and lattice deformation are increased with increasing calcium concentration. SEM analysis revealed that Ti 1−x Ca 2x O 2 (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 TiO 2 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 Ti 1−x Ca 2x O 2 (0≤ x ≤0.5) samples for optical and optoelectronic applications.