Related Experiment Videos
Strong nonlinear current-voltage behaviour in perovskite-derivative calcium copper titanate
Sung-Yoon Chung1, Il-Doo Kim, Suk-Joong L Kang
1Department of Materials Science and Engineering, Inha University, Incheon 402-751, Korea. sychung@inha.ac.kr
Abstract:
The discovery of a giant dielectric constant of 10(5) in CaCu(3)Ti(4)O(12) has increased interest in this perovskite-type oxide. Here we demonstrate that, in addition to high permittivity, CaCu(3)Ti(4)O(12) has remarkably strong nonlinear current-voltage characteristics without the addition of any dopants. An intrinsic electrostatic barrier at the grain boundaries is responsible for the unusual nonlinear behaviour. The nonlinear coefficient of CaCu(3)Ti(4)O(12) reaches a value of 900, which is even greater than that of the varistor material ZnO. As a result, CaCu(3)Ti(4)O(12) may lead to efficient switching and gas-sensing devices.