PbTiO 3 thin films on Si(100) as potential varistor material

We have shown that the aqueous sol derived thin films of PbTiO3 on Si(100) substrate exhibit strong varistor type of behavior for certain annealing conditions. Current–voltage (I–V) characteristics depend upon the processing conditions. The behavior is explained by grain boundary limited conduction model. Since the resistance of the grain boundaries varies with the processing conditions, grain boundaries in all samples do not act as potential barriers to the charge carriers. The film postannealed at 700 °C, possessing high nonlinear coefficient (α) with low breakdown voltage per barrier (Egbl), could be used as a protection device in current-sensitive electronic equipment.