Comparative characteristics of silver and copper electrodes on ZnO varistor ceramics

Abstract The current–voltage characteristics of zinc oxide-based ceramics with silver electrodes created by silver baking and with copper electrodes obtained by electrodeposition of copper have been investigated in wide region of electric current. For ZnO varistors with copper electrodes the leakage current in 3–4 times is less than for varistors with silver electrodes. The reason of it is a thermal influence on ceramics at creation of silver electrodes. The transition layer between ceramics and the copper electrode, which has a negative influence on current–voltage characteristic at region of high electric current was not detected. The raster electronic microscopy indicates a good contact between ceramics and the copper electrode. The tearing strength for copper electrode is (8.21±3.03)×10 6 newton·m −2 and is close to similar magnitude for a silver electrode.