DIELECTRIC BEHAVIOR OF POTASSIUM ACETYLACETONATE

The dielectric constant and the dielectric loss of potassium acetylacetonate, K(acac), are measured as a function of both temperature and frequency. A peak value is obtained at the a critical temperature T(c) = 313 K. X-ray analysis revealed that at T(c), K(acac) undergoes phase transition from orthorhombic to triclinic structure. The Cole-Cole diagrams have been used to determine the molecular relaxation time-tau. The temperature dependence of tau is expressed by thermally activated process. The impedance spectra in the frequency range from 50 Hz to 500 kHz plotted in the complex plane show semicircles. The conduction mechanism, below T(c), is predominantly operating at the surface. Above T(c), the conduction is proceeding in the bulk material with contribution from the surface.