The behavior of silver as the solid oxide fuel cell SOFC cathode material was investigated. Ag vertical bar Gd0.2Ce0.8O1.9 half cells were cathodically polarized at the temperatures between 300 and 700 degrees C at the potential of -0.5 V. Changes in the morphology and electronic states of the electrolyte surface on the cathodic side were examined by the Scanning Electron Microscopy and Energy Dispersive X-ray Spectroscopy. Silver deposits arose around the point where electrodes contact the electrolyte. The negative polarization did not change electronic states of cerium and gadolinium in the electrolyte surface region. The mechanism of the silver migration is proposed. (C) 2013 Elsevier Ltd. All rights reserved.