Nanocrystalline barium titanate (BT) was synthesized by the sol gel method. The dry gel obtained was first treated in themicrowave (MW) and then calcined at different temperatures. A pure tetragonal phase was obtained under heat treatmentat 750 oC which is a relatively low temperature. SEM image reveals a fairly dense and uniform microstructure. Dielectricmeasurements performed on the sintered BaTiO3 sample at 1200 oC revealed the presence of the resonance phenomenon atfrequencies lower than 2 MHz and the existence of a weak positive temperature coefficient of resistivity (PTCR) just abovethe Curie temperature. Electric impedance analysis shows the predominance of the grain boundary (gb) contribution andenables determination of activation energies of the gb and the bulk effect and their relative capacitance and resistanceelements.

Keywords: Nanocrystalline BaTiO3, Sol gel process, Microwave, PTCR, Resonance