Dielectric Properties of CaCu3Ti4O12 Ceramic Thin Films

In CaCu3Ti4O12 (CCTO), the ceramic material with the highest dielectric permittivity ever reported in a broad frequency and temperature range, the origin of such high permittivity has been attributed to ‘electrical’ heterogeneities in the microstructure. Dielectric investigations of CCTO ceramic thin films, performed in a broad temperature and frequency range, and the analysis in terms of the equivalent circle reveal that (i) each of the two constituents, insulating grain boundaries and semiconducting bulk grains, individually determines the dielectric behaviour of CCTO and (ii) manipulating the conditions under which CCTO ceramic thin films are prepared enables control of their dielectric properties.