Capacitance-voltage relation for ceramics with positive temperature coefficient of resistance

A capacitance-voltage relation to determine the potential barrier height for ceramics with positive temperature coefficients of resistance (PTCR) was proposed. The suggested relation, (1/C-2-1/2C(0)2)(2) versus V-2, was derived based on the double Schottky barrier formation at the grain boundary and the linear distribution of bias along the depletion region. The linearity of the relation was evaluated for two types of PTCR ceramic specimens with different grain sizes. Also, the barrier heights determined from the plots were compared with those reported by other researchers. The potential barrier heights, determined at various temperatures for PTCR ceramics using the capacitance-voltage relation, were in the range of 0.36-0.80 V. (C) 2002 American Institute of Physics.