Modelling Power Law Dependencies of Frequency Dependent AC Conductivity and Permittivity of Conductor-Relaxor Composites

C R Bowen, A C E Dent, D P Almond, T P Comyn

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7 Citations (Scopus)

Abstract

Porous lead magnesium niobate-lead titanate (PMN-PT 90:10) relaxors were impregnated with water to provide a model conductor-insulator mixture, to study their power law frequency dependency of ac conductivity, permittivity and phase angle. Relaxor materials with a range of open porosity filled with water created composites with conductor volume fractions ranging from 8.2% to 22.2%. The use of a high relative permittivity PMN-PT ( 8000) enabled the power law dispersion to be observed at relatively low frequencies ( 2 kHz). Good agreement was obtained between experimental data and predicted results based on a logarithmic mixing rule with a strong correlation between the power law exponent and conductor-insulator fraction. The model and numerical methods presented are considered a simple approach to interpret and predict and the frequency dependent properties of materials which similar heterogeneity.
Original languageEnglish
Pages (from-to)166-175
Number of pages10
JournalFerroelectrics
Volume370
Issue number1
DOIs
Publication statusPublished - 2008
Event11th European Meeting on Ferroelectricity - Bled, Slovenia
Duration: 3 Sep 20077 Sep 2007

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