Investigation of the conductivity of Na2SO4–PbTiO3 composite electrolyte system: Non linear electrical behavior at Curie temperature of the dispersoid

• Published in: Solid state ionics Vol. 178; no. 29-30; pp. 1585 - 1589
• Main Authors: BOBADE, S, KULKARNI, A, GOPALAN, P
• Format: Journal Article
• Language: English
• Published: 01.12.2007
• ISSN: 0167-2738
• DOI: 10.1016/j.ssi.2007.10.001

The effect of dielectric constant of the PbTiO3 dispersoid on the conductivity of Na2SO4 has been probed. At the Curie temperature, 490 deg C, PbTiO3 undergoes ferroelectric to paraelectric phase transition followed by a sharp change in the dielectric constant. The Na2SO4-PbTiO3 composites have been prepared at two different temperatures, namely 600 and 900 deg C. Compositions containing 5, 10, 20, 30, 40, 50m% PbTiO3 have been investigated using Impedance Spectroscopy, Differential Scanning Calorimetry (DSC), X-ray diffraction (XRD) and Rietveld analysis. The series of compositions prepared at 900 deg C exhibit a maxima in the conductivity for 20m% PbTiO3. The composites prepared at 600 deg C exhibit a peak in the conductivity at 20m% PbTiO3 in addition to the percolation threshold at 40m% PbTiO3. The enhancement in the conductivity by a factor of 40 at 300 deg C has been observed for the system prepared at 600 deg C while an enhancement in the conductivity by a factor of 8 at 300 deg C has been observed for the system prepared at 900 deg C. Further, the transition temperature of Na2SO4 remains unaltered for both series. A slight nonlinearity has been observed in the vicinity of the transition temperature of the dispersoid.