A STUDY OF BATIO3-BAPBO3 CERAMIC COMPOSITES

The ceramic composites prepared from donor-doped ceramic BaTiO3 and th e conducting ceramic BaPbO3 are studied in the present paper. The XRD result shows that the composites consist of the BaTiO3 phase and the B aPbO3 phase. An abrupt decrease in the curve of resistivity versus BaP bO3 content was observed; this was explained by the three-dimensional percolation model for the two-phase BaTiO3-BaPbO3 composite, and the p ercolation volume threshold phi(c) obtained was near 0.14. Beyond the percolation threshold, the electrical transport properties of the comp osites are similar to those of BaPbO3 ceramics, The positive temperatu re coefficient effect found in donor-doped BaTiO3 disappears above a B aPbO3 volume fraction of about 0.04.