Electrical and microstructural properties of CaTiO3-doped K1/2Na1/2NbO3-lead free ceramics

Microstructure, electrical properties and dielectric behaviour of K_1/2Na_1/2NbO₃ (KNN) and CaTiO₃-modified K_1/2Na_1/2NbO₃ (CTO-KNN) systems, were investigated. Discs doped with 0 to 0·55% mol of CaTiO₃ (CTO) were sintered at 1125°C for 2 h. Although minority phases were found in doped samples, CaTiO₃ was not detected. It was also observed that CTO changed the microstructure and grain size of KNN drastically. Also, the Curie temperature and permittivity values decreased. Addition of CTO between 0·15 and 0·45 mol% decreases the density and dielectric values. Samples prepared with higher content of CTO than 0·45 mol% showed better electrical properties.