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Voltage–Current Nonlinearity of CaCu 3 Ti 4 O 12 Ceramics
Author(s) -
Lu ZhenYa,
Li XiaoMing,
Wu JianQing
Publication year - 2012
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2011.05025.x
Subject(s) - thermionic emission , materials science , current (fluid) , varistor , ceramic , nonlinear system , analytical chemistry (journal) , voltage , condensed matter physics , direct current , thermodynamics , electrical engineering , chemistry , composite material , physics , quantum mechanics , engineering , electron , chromatography
Ceramic samples of CaCu 3 Ti 4 O 12 ( CCTO ) were prepared and the voltage–current characteristics were investigated. Extremely strong nonlinear behavior, similar to the reported results in literature [Nature Materials 3 [11] 774–8 (2004); Appl. Phys. Lett., 89 [19] 191907 (2006); Appl. Phys. Lett., 89 [21] 212102 (2006); Appl. Phys. Lett., 91 [9] 091912 (2007)] was observed. However, we found that this is a measurement artifact due to a thermionic emission current feedback amplification effect. Compared to that of ZnO varistor, the thermionic emission current of CCTO sample is about six orders of magnitude higher and it is feedback amplified due to strong negative temperature coefficient resistance behavior when the CCTO sample is tested with a voltage (or current) source. Eliminating the thermionic emission current feedback amplification effect, the true value of nonlinear coefficient of the CCTO sample is much lower.