Relationship between the dielectric constant and the porosity of mica foils

We studied different schemes for calculating the properties of two-component mixtures as applied to mica foils of the mica-sheet type. The dielectric constant of mica-sheet foils with a porosity of 0.3-0.5 in the frequency band 10/sup 3/-10/sup 8/ Hz was approximated well by Bruggemann's and Lichtenecker's equations.