Impedance/Dielectric Spectroscopy of Electroceramics in the Nanograin Regime

Published

December 3, 2002

Author(s)

N Kidner, Z J. Homrighaus, B J. Ingram, T Mason, Edward Garboczi

Abstract

In the microcrystalline regime, the behavior of grain boundary-controlled electroceramics is well described by the brick layer model (BLM). In the nanocrystalline regime, however, grain boundary layers can represent a significant volume fraction of the overall microstructure and simple layer models are no longer valid. This work describes the development of a pixel-based finite-difference approach to treat a nested cube model (NCM), which more accurately calculates the current distribution in polycrystalline ceramics when grain core and grain boundary dimensions become comparable. Furthermore, the NCM approaches layer model behavior as the volume fraction of grain cores approaches unity (thin boundary layers) and it matches standard effective medium treatments as the volume fraction of grain cores approaches zero. Therefore, the NCM can model electroceramic behavior at all grain sizes, from nanoscale to microscale. It can also be modified to handle multi-layer grain boundaries and property gradient effects (e.g., due to space charge regions).

Proceedings Title

Solid-State Ionics 2002, Materials Research Society Fall Meeting. Volume 756

Volume

756

Conference Dates

October 1, 2002

Conference Location

Undefined

Conference Title

MRS Meeting

Pub Type

Conferences

Download Paper

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Keywords

dielectric spectroscopy, electroceramics, impedance spectroscopy, modelling, nanocrystalline

Citation

Kidner, N. , Homrighaus, Z. , Ingram, B. , Mason, T. and Garboczi, E. (2002), Impedance/Dielectric Spectroscopy of Electroceramics in the Nanograin Regime, Solid-State Ionics 2002, Materials Research Society Fall Meeting. Volume 756, Undefined, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=860481 (Accessed July 18, 2024)