Structural, Dielectric and Electrical Studies of Ba5-xCaxSmTi3Nb7O30 (x = 0,1) Ferroelectric Ceramics

Abstract

In the present work, samples of compositions Ba_5-xCa_xSmTi₃Nb₇O₃₀ (x = 0, 1) were prepared by solid state reaction method. X-ray diffractographs (XRD) show the formation of single phase samples. Microstructural studies of the specimen have been performed by scanning electron microscopy (SEM). Detailed dielectric properties of the compounds as a function of frequency and temperature show that the compounds undergo non-relaxor kind of ferroelectric-paraelectric phase transition of diffuse nature with the increase in Curie temperature (T_c) on the substitution of calcium. The temperature dependence of dc conductivity shows that the conductivity increases with increase in temperature suggesting that the compounds have a negative temperature coefficient of resistance (NTCR) behaviour.