Electrical characterization and modelization of CaCu₃Ti₄O₁₂ polycrystalline ceramics^*

¹ Université de Toulouse, UPS, INPT, LAPLACE (Laboratoire Plasma et Conversion d’Énergie), 118 route de Narbonne, 31062 Toulouse Cedex 9, France
² CNRS, LAPLACE, 31062 Toulouse, France
³ Centre Universitaire Jean-François Champollion, Place de Verdun, 81012 Albi Cedex, France
⁴ Institut Carnot CIRIMAT (Centre Inter-universitaire de Recherche et d’Ingénierie des Matériaux), Université Paul Sabatier, 18 route de Narbonne, 31062 Toulouse Cedex 9, France

^a e-mail: valdez@laplace.univ-tlse.fr

Received: 1 February 2015
Revised: 21 April 2015
Accepted: 21 April 2015
Published online: 24 June 2015

Abstract

Since the observation almost 15 years ago of the so-called “colossal” dielectric permittivity behavior in CaCu₃Ti₄O₁₂ (CCTO) ceramics, several works have been undertaken to understand its physical origin interfacial polarization being the most likelihood. In this paper, (C-V) measurements, commonly used on semiconducting materials have been used to characterize CCTO samples. Their results may be described by a head-to-tail double metal-insulating-semiconductor (MIS) structure. A comparison between experimental and numerical simulation results of such a structure shows a good agreement, whatever the frequency range. Furthermore, this model explains the non-symmetrical behavior of the electrical response of this material, a property still not taken into account by today’s commonly known models.