RT Journal Article
T1 ac hopping admittance in spinel manganate negative temperature coefficient thermistor electroceramics
A1 Schmidt, Rainer
A1 Brinkman, Andrew W.
AB In this work, the ac admittance of a thick film nickel manganate spinel negative temperature coefficient thermistor ceramic system containing a glass phase is investigated. The dominating relaxation process is a grain boundary (GB) effect and has been investigated comprehensively. We present double-logarithmic plots of the specific admittance σ' vs ω   and (σ'/σ_(dc)) vs ω, and specific impedance z vs −z"/ω and [(ρ_(dc)/z')−1] vs ω, in order to characterize GB charge transport. Using the complex admittance notation (σ*), an unusually low Jonscher exponent of frequency ~0.007 was obtained and the GB relaxation displayed close to ideal behavior.
PB American Institute of Physics
SN 0021-8979
YR 2008
FD 2008-06-01
LK https://hdl.handle.net/20.500.14352/51556
UL https://hdl.handle.net/20.500.14352/51556
LA eng
NO © 2008 American Institute of Physics. The authors wish to thank Michael Petty for allowing use of the ac impedance spectroscopy facility. Thanks to Finlay Morrison and Ian Terry for useful discussions concerning impedance spectroscopy data analysis. Thanks to Andreas Roosen and Alfons Stiegelschmitt for the guidance provided in developing thick film samples.
DS Docta Complutense
RD 7 abr 2025