Electrical conductivity of random silver-potassium chloride composites

The complex alternating current (a.c.) impedance of random silver-potassium chloride (Ag-KCl) composite specimens near the percolation threshold has been measured in the frequency range 5 Hz to 13 MHz. The impedance of these composites as a function of metal volume fraction and direct current (d.c.) potential field are presented. This a.c. response, which is correlated with structural and compositional characterization of these composites, is used to examine the applicability of several different theoretical models as well as to determine the important factors in the electrical conductivity of such materials.