Impedance spectroscopy of BaTiO3 cubes suspended in lossy liquids as a physical model of two-phase system

Impedance spectroscopy techniques were used for analysis of the physical model in a two-phase system toward determining of dielectric constant of dielectric particles suspended in liquids at various solids loading (volume fraction) levels. Model experimental studies were conducted using BaTiO3 as a dielectric material that was prepared as small cubes of uniform size (2 x 2 x 1 mm). Barium titanate (BT) cubes having a dielectric constant of 3850 were immersed in liquids of low dielectric constant and moderate electrical conductivity. Measured impedance spectra consisted of two semicircles, which were fitted for (R parallel to C) (R parallel to C) equivalent circuit. The parameters obtained from fitting were compared with the data acquired from simulations of brick layer models and Maxwell-Wagner effective media model. In the investigated range of volume fractions the Maxwell-Wagner model correlates well with the data extracted from measurements. (C) 2010 American Institute of Physics. [doi:10.1063/1.3486461]