The dielectric suppress and the control of semiconductor non-Ohmic feature of CaCu3Ti4O12 by means of tin doping

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

In this work it was demonstrated that the addition of Sn on CaCu3Ti4O12 material improved non-Ohmic behavior by suppressing dielectric properties. It was noted that the improvement of the varistor characteristics, monitored by the increase in nonlinear coefficient, occurs with the disappearance of the grain dielectric relaxation process with concomitant decreasing of both dielectric constant and dielectric loss values. By forming a solid solution, Sn4+ was incorporated into CaCu3Ti4O12 matrix deforming the crystal lattice and restricting the formation of polaronic stacking faults. Thus, the dielectric relaxation due to polaronic defects is believed to be the origin of the huge dielectric properties disappearance. This framework is in agreement with the nanosized barrier layer capacitor model. (C) 2011 American Institute of Physics. [doi:10.1063/1.3574016]