Dielectric properties and impedance versus dc bias and I–V characteristics of La2/3Cu3Ti4O12 ceramics.

The La2/3Cu3Ti4O12 (LCTO) ceramic samples with a higher permittivity were prepared by the sol-gel technique. The study indicated that the effects of dc bias on grain boundaries electrical properties were very evident, but the grain electrical properties were independent of dc bias. The dielectric constant decreased whereas the dielectric loss increased with increasing of dc bias, and the resistances and the activation energies of grain boundaries decreased. According to the analysis of impedance and the I–V curve, there was a potential barrier existed at the grain boundaries of LCTO ceramic samples, which be considered as the Schottky potential barriers. [ABSTRACT FROM AUTHOR]