Strong nonlinear current-voltage behaviour in perovskite-derivative calcium copper titanate.
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.
Department of Materials Science and Engineering, Inha University, Incheon 402-751, Korea. sychung@inha.ac.kr
Sung-Yoon
SY
Chung
Il-Doo
ID
Kim
Suk-Joong L
SJ
Kang
D002118:Calcium / Q000737:chemistry*; D017610:Calcium Compounds / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*; D055672:Static Electricity; D014025:Titanium / Q000737:chemistry*
D017610:Calcium Compounds; D010087:Oxides; C059910:perovskite; D003300:Copper; D014025:Titanium; D002118:Calcium