The dielectric constants of current-blackened single crystral yttria-stabilized zirconia

The dielectric constants of 8 mol % single crystal yttria-stabilized zirconia have been measured, using both radio-frequency and microwave methods, before and after blackening by high temperature electrolysis. For as-grown material = 38±4 and tan = 0.004. After electrolysis both the dielectric constant and loss tangent of the current-blackened material increased; this experimental data has been compared with theoretical predictions for composite dielectrics. The dielectric behaviour in the current-blackened material was consistent with the formation of metallic particles; these initially appeared to be spherical but elongated as electrolysis proceeded.