Representations of impedance spectra of ceramics - Part I. Simulated studycases

The present work demonstrates that the representation of log(tg(delta)) vs, log(f) may be best suited to reveal the bulk, grain boundary, and electrod e contributions of impedance spectra, and to extract the relevant parameter s. Alternative representations of Z" vs. Z', log(Z") vs. log(f), log(M") vs , log(f), and log(A") vs. log(f) often have a limited applicability. The lo g(tg(delta)) vs. log(f), and log(A") vs. log(f) plots show peaks or minima at frequencies that are somewhat displaced relative from the true relaxatio n frequencies, or transitions from the electrode to grain boundary, or grai n boundary to bulk contributions. Suitable criteria are proposed to account for these differences. (C) 2000 Elsevier Science Ltd. All rights reserved.