Influence of Ca additives on the optical and dielectric studies of sol–gel derived PbTiO3 ceramics

Sintered ceramic powders of calcium-doped lead titanate [Pb1−xCaxTiO3] ceramics with different Ca dopant concentration in the range (x=0–0.35) have been prepared using a sol–gel chemical route. The sol–gel technique is known to offer better purity and homogeneity, and can yield stoichiometric powders with improved properties at relatively lower processing temperature in comparison to conventional solid-state reaction. X-ray diffraction (XRD) and Raman spectroscopy studies have been carried out to identify the crystallographic structure and phase formation. The infrared absorption spectra in the mid-IR region (400–4000 cm−1) show the band corresponding to the Ti–O bond at ∼576 cm−1 and is found to shift to a higher wave number 592 cm−1 with increasing Ca content. The dielectric properties as a function of frequency, and phase transition studies on sintered ceramic Pb0.65Ca0.35TiO3 has been investigated in detail over a wide temperature range 30–600 °C and the results are discussed.