DIELECTRIC-PROPERTIES OF A LOW-TENSION PORCELAIN USING AC IMPEDANCE SPECTROSCOPY

A.C. impedance spectroscopy technique was used to investigate the diel ectric properties of low tension porcelain specimens.The dielectric pa rameters involved were obtained using equivalent electric circuits. It was possible to analize the electric behaviour as a function of tempe rature from both grain and grain boundary separatelly. D.C. component and hopping rate characteristics were also investigated using the same a.c. data. Mixed conduction character was stablished for these compou nds.The conductivity is 10(-8) (W cm)-1 at 470 K, raising to 10(-4) (W cm)-1 at 870 K, with an activation energy of 0.8 ev.