Discontinuous immitance due to a saddle node bifurcation - II: Tangent bifurcation and critical slowdown during isotherm branch switching

The qualitative changes in behaviour that can take place during an impedanc e spectroscopy study of an electrosorption reaction in the presence of an a ttractive interaction in the adsorbed phase have been investigated along wi th the mechanisms associated with switching between the branches of the ele ctrosorption reaction isotherm. Isotherm branch switching corresponds to a tangent bifurcation and can entail a critical slowdown during impedance mea surements. The transition between a low-amplitude harmonic cycle and a high -amplitude relaxation cycle is brutal but continuous and is not a true bifu rcation. (C) 1999 Elsevier Science S.A. All rights reserved.