Microstructure and electric characteristics of AETiO3 (AE=Mg, Ca, Sr) doped CaCu3Ti4O12 thin films prepared by the sol–gel method

Abstract

This paper focuses on the effects of alkline-earth metal titante AETiO3 (AE=Mg, Ca, Sr) doping on the microstructure and electric characteristics of CaCu3Ti4O12 thin films prepared by the sol–gel method. The results showed that the grain size of CCTO thin films could be increased by MgTiO3 doping. The movement of the grain boundaries was impeded by the second phases of CaTiO3 and SrTiO3 concentrating at grain boundaries in CaTiO3 and SrTiO3 doped CCTO thin films. Rapid ascent of dielectric constant could be observed in 0.1Mg TiO3 doped CCTO thin films, which was almost as three times high as pure CCTO thin film and the descent of the dielectric loss at low frequency could also be observed. In addition, the nonlinear coefficient (α), threshold voltage (VT) and leakage current (IL) of AETiO3 doped CCTO thin films (AE=Mg, Ca, Sr) showed different variation with the increasing content of the MgTiO3, CaTiO3 and SrTiO3.