Figure 3. Time-dependent emf measurements for Ag/Ge_0.3Se_0.7/Pt ECM cells.

After a SET/RESET cycle (initial state), a negative voltage is applied to the Ag electrode resulting in a dendrite formation. At t₁=0 s the voltage measurement is started. Fading of the diffusion potential contribution from t₁ to t₂ leads to a highly negative V_cell owing to a significant Nernst potential between the electrodes. In parallel to the dissolution of the dendrites (t₂), the emf increases to positive values again with a diffusion potential as the remaining component of the emf owing to the different activity of Ag⁺ ions at the both s′, s″ surfaces (t>t₃). The scale bar in the inset corresponds to 20 μm.