This paper proposes a polaronic stacking fault defect model as the origin of the

huge dielectric properties in CaCu3Ti4O12 materials. The model reconciles the

opposing views of researchers on both sides of the intrinsic versus extrinsic debate

about the origin of the unusually high values of the dielectric constant measured for

this material in its various forms. Therefore, by considering stacking fault as the

origin of the high dielectric constant phenomena, it was shown that the internal

barrier layer capacitance mechanism was enhanced by another similar, but different

in nature, mechanism that operates in the nanoscale range due to polaron defects

associated with stacking fault, a mechanism that was referred to as nanoscale barrier layer capacitance. The latter approach explained the origin of the material’s

huge dielectric constant, coexisting with semiconducting features.

A Polaronic Stacking Fault Defect Model for CaCu3Ti4O12 Material: an Approach

for the Origin of the Huge Dielectric Constant and Semiconducting Coexistent

Features. P.R.Bueno, R.Tararan, R.Parra, E.Joanni, M.A.Ramírez, W.C.Ribeiro,

E.Longo, J.A.Varela: Journal of Physics D, 2009, 42[5], 055404