Impedance and modulus spectroscopy of semiconducting BaTiO3 showing positive temperature coefficient of resistance
- 15 October 1989
- journal article
- conference paper
- Published by AIP Publishing in Journal of Applied Physics
- Vol. 66 (8) , 3850-3856
- https://doi.org/10.1063/1.344049
Abstract
Polycrystalline barium titanate that has been doped to give a positive temperature coefficient of resistance (PTCR) effect is an inhomogeneous material electrically. Analysis of ac impedance data using the complex impedance plane representation gives the dc resistance of PTCR ceramics. By additional use of the complex electric modulus formalism to analyze the same data, the inhomogeneous nature of the ceramics may be probed. This reveals the presence of two, sometimes three elements in the equivalent circuit. Grain-boundary and bulk effects may be distinguished from capacitance data: grain-boundary effects have temperature-independent capacitances, whereas bulk effects show a capacitance maximum at the Curie point and Curie–Weiss behavior above the Curie point. Both grain-boundary and bulk effects appear to contribute to the PTCR effect. These results reveal limitations in current theories of the PTCR effect.This publication has 7 references indexed in Scilit:
- BulkPTC effect on doped BaTiO3Journal of Materials Science Letters, 1988
- PTC Behaviour of Semiconducting BaTiO3CeramicsTransactions of the Indian Ceramic Society, 1986
- EPR evidence for activation of trap centers in PTCR BaTiO3 ceramicsMaterials Research Bulletin, 1985
- Impedance and modulus spectroscopy of polycrystalline solid electrolytesJournal of Electroanalytical Chemistry and Interfacial Electrochemistry, 1976
- Semiconducting barium titanateJournal of Materials Science, 1971
- Electrical Conduction Anomaly in Samarium‐Doped Barium TitanateJournal of the American Ceramic Society, 1963
- Properties of Semiconductive Barium TitanatesJournal of the Physics Society Japan, 1959