A Study of the Volume Fraction, temperature and Pressure Dependence of the Resistivity in a Ceramic–Polymer Composite using a General Effective media Equation

ABSTRACTA General Effective Media (GEM) equation is used to quantitatively describe the resistivity of an Fe304-eccogel composite system as a function of the relative volume fractions. The two percolation morphology parameters (øc and t) characterise the microstructure. Preliminary models, also based on the GEM equation, are used to describe the positive temperature coefficient of resistivity (PTC) and the piezoresistivity (uniaxial pressure) of the composite when the composition is near the percolation threshold.