Microstructural design of BaTiO3-based ceramics for temperature-stable multilayer ceramic capacitors

In order to satisfy EIA X8R specification, a new type of BaTiO3-based ceramic with hierarchical structure in a formula scheme a ferroelectric ABO(3) + another ferroelectric ABO(3), was designed. There were (Ba, Bi)TiO3 and Ba(Ti, Zr)O-3 phases with different Curie temperatures coexisting in the grains from inside to outside, prepared by wet chemical method under 100 degrees C. The hierarchical structure of the ceramic grains was proved by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). The dielectric constant of (Ba, Bi)TiO3-Ba(Ti, Zr)O-3 ceramic was similar to 6000, the Delta C/C-20 degrees C was -12.0%, 14.1%, and -8.3% at -55 degrees C, 130 degrees C, and 160 degrees C, respectively, and the dielectric loss is less than 0.1, which is obviously superior to (Ba, Bi)TiO3 and Ba(Ti, Zr)O-3. The results of this work showed that the formula scheme a ferroelectric ABO(3) + another ferroelectric ABO(3) for solid solutions is a promising approach to prepare high performance temperature-stable capacitor materials. (c) 2012 Elsevier Ltd and Techna Group S.r.l. All rights reserved.