We have shown that the aqueous sol derived thin films of PbTiO3 on Si(
100) substrate exhibit strong varistor type of behavior for certain an
nealing 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 boundarie
s varies with the processing conditions, grain boundaries in all sampl
es do not act as potential barriers to the charge carriers. The film p
ostannealed at 700 degrees C, possessing high nonlinear coefficient (a
lpha) with low breakdown voltage per barrier (E-gbl), could be used as
a protection device in current-sensitive electronic equipment. (C) 19
97 American Institute of Physics. [S0003-6951(97)04151-X].