Relaxor ferroelectric like giant permittivity in PrCrO3 semiconductor ceramics

The electrical behavior of PrCrO₃ ceramics prepared by citric acid route and sintered at 1200 °C has been characterized by a combination of permittivity measurements, and impedance spectroscopy (IS). The effective permittivity obtained in frequency range 100 Hz to 1 MHz and temperature range 80–300 K, exhibits giant permittivity value of 3 × 10⁴ near room temperature. The response is similar to that observed for relaxor ferroelectrics. IS data analysis revealed the ceramics to be electrically heterogeneous semiconductor with room temperature resistivity <10² Ω m consisting of semiconducting grains with permittivity ?′ ∼ 100 and more resistive grain boundaries with effective permittivity ?′ ∼ 10⁴. We conclude, therefore that grain boundary effect is the primary source for the high effective permittivity in PrCrO₃ ceramics.