Microstructure and dielectric properties of nano-grained X7R type BaTiO3 ceramic capacitors sintered by 2.45GHz microwave

摘要

Systematic investigation on the effects of microwave sintering on the characteristics of nano-grained BaTiO3 (BT) capacitor materials co-doped with yttrium (Y) and magnesium (Mg) elements was carried out. The granular structure in these materials was observed to be relatively insensitive to the sintering temperature and soaking time. The nano-sized BaTiO3 capacitor materials possessing X7R dielectric constant-temperature (K-T) characteristics have been obtained over a wide range of sintering conditions. Transmission electron microscope (TEM) examinations revealed that the detailed microstructural study of these materials is extremely complicated. The unique K-T properties of the materials are ascribed to the duplex structure in the samples, namely finer grains of paraelectric phase and larger grains of ferroelectric phase.