A study of the structural, optical, and dielectric properties of (Ca 1− x Cu x )TiO 3 powders prepared by sol–gel process

In this work, Ca 1− x Cu x TiO 3 samples ( x = 0 (CTO), x = 0.04 (CCTO 0.04 ) and x = 0.08 (CCTO 0.08 )) were synthesized via the sol–gel method. The influence of A-site copper substitution on the structural, optical, and dielectric properties of Ca 1− x Cu x TiO 3 powders was investigated. X-ray diffraction (XRD) confirmed the formation of a pure perovskite structure. Moreover, Rietveld refinement revealed the crystallization of all samples under the orthorhombic Pbnm structure with the appearance of a minor secondary cubic phase with Cu 2+ incorporation in the CaTiO 3 host lattice. The vibrational investigation using Micro-Raman (MR) spectroscopy confirmed XRD results. Moreover, MR analysis revealed that A-site copper substitution results in the displacement of Ti atoms which induces distortions in the lattice. Ultraviolet–Visible (UV–Vis) absorption and photoluminescence (PL) measurements revealed the effect of copper-induced structural defects, distortions, and/or strains on the optical properties. Furthermore, the dielectric studies indicated high-temperature stability of the dielectric properties of the samples over a broad temperature range. The photoluminescence and dielectric results suggest that Ca 1− x Cu x TiO 3 powders are promising materials for potential use in several electronic devices such as capacitors and light-emitting devices.