Relative permittivity variation with temperature

Figure 11.16. Variation of apparent relative permittivity ofBaTiO with temperature. Case of a single crystal...

Fig. 5.1 Photographs of relief models showing the variation of relative permittivity and dielectric loss of poly(ethyleneterephthalate) with temperature and frequency of measurement. From Reddish (1950) with permission of the Royal Society of Chemistry.

Although the ceramic phase of the composite makes the material electroactive, many of the important properties of the material are derived primarily from the properties of the polymer. Also, the choice of polymer can determine whether the best ceramic sensitivity can be realized. The electrical properties to be considered are the resistivity p, the relative permittivity (dielectric constant) the dielectric loss, the dissipation factor D, the power factor F and the dielectric strength. The variation of these properties with changes in the likely environment should also be considered, since many of them vary with temperature, frequency and humidity. 

Figure 11.41. Variations of relative permittivity with temperature. Influence of grain size...

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