Artigo de peri??dico
Influence of probe size for local electrochemical impedance measurements
Registro en:
0013-4686
233
10.1016/j.electacta.2017.03.017
83.929
Autor
ABREU, CAIO P. de
ASSIS, CAMILA M. de
SUEGAMA, PATRICIA H.
COSTA, ISOLDA
KEDDAM, MICHEL
MELO, HERCILIO G. de
VIVIER, VINCENT
Resumen
Local electrochemical impedance spectroscopy (LEIS) is a promising technique for the characterization of
heterogeneous surface reactivity. Significant development of LEIS relies on the improvement of the
spatial resolution for reaching the micrometer scale. This work presents the influence of the probe size,
especially in the high frequency domain where an inductive-like response ascribed to the stray dielectric
capacitance between the two electrodes of the probe used for performing the local current measurement
can be observed. A detailed analysis of the whole set-up (electrode geometry and measuring device)
allows an analytical expression of the impedance for the whole system to be obtained. Based on the
analysis of this expression and on experimental results, two different strategies have been proposed to
cancel the HF time constant: a post treatment of the results via a preliminary electrical characterization
of the local probe or the minimization of the electrolyte resistance by measuring the local potential in the
close vicinity of the substrate. Both approaches were shown to be efficient.