Dielectric study of calcium doped barium titanate Ba1-xCaxTiO3 ceramics

Abstract

Calcium doping effect on the ferroelectric properties of Ba1-xCaxTiO3: BCTx (x = 0.01, 0.05, 0.1) ceramic material prepared via the sol-gel process was studied. X-ray diffraction (XRD) showed that the powders of calcined BCTx at 900°C crystallize in a pure phase of perovskite type without secondary phases. Microstructural morphology was analyzed by Scanning Electronic Microscopy (SEM). Dielectric measurements were carried out by an analyzer of impedance in an active temperature range from ambient to 400°C for various frequencies (0.1 kHz – 1 MHz). The modeling of the permittivity shows a thermal behavior controlled by the traditional Curie-Weiss law and the transition remains of first order for all the concentrations studied similar to that of the BaTiO3 sample.   Key words: BCT, Sol-Gel, Ferroelectric, SEM, Curie