A conduction model for BaPbO3-based thick film resistors

BaPbO₃-based thick film resistors were fabricated using BaPbO₃ powders and alkali glass frits. From microstructure observations, the conductive mechanisms are assumed to be related to the contact conditions between particles, and by means of EMT (effective-medium theory) approximation for some possible distributions, a more possible conductive model is proposed. This model is composed of trinary conductive channels, i.e., continuous, semi-continuous, and discontinuous, corresponding to a distribution function of the contact conductance, which is composed of trinary contact conditions, i.e., good contact, poor contact (both with same probability density) and no contact between BaPbO₃ particles. This model can explain the blending curve, temperature dependence and field dependence of resistivity of the specimens