DIELECTRIC FREQUENCY DISPERSION BEHAVIOR IN FLUX GROWN PBTIO3 SINGLE-CRYSTALS

The dielectric behavior (dielectric constant and dielectric loss) of nux grown PbTiO3 single crystals has been examined at frequencies ranging from 10 Hz to 13 MHz. Large dielectric frequency dispersion has been found. Removing the surface layers of the as-grown crystal or heat treatment can significantly change the dispersion behavior and the dc conductivity. It is suggested that a concentration gradient of defects exists within the as-grown PbTiO3 single crystals. The migration of he ionic defects within the crystals is responsible for the observed dielectric frequency dispersion behavior.