Janusz Stafiej

Title : Oscillatory behavior in a cellular automaton based model of metal passivation

Abstract:

Passivating systems display potential or electric current oscillations in galvanostatic or potentiastic control, respectively. Their occurrence is related to the negative differential resisitivity observed on the potenial vs electric current dependence commonly called polarization curve. Our cellular automata based model reproduced such polarization curves for the stationary regime.Here we show that our simulations reproduce either potential or electric current oscillations in galvanostatic or potentiastic conditions respectively. Compared to other modelling approaches we can see morphology variations during several oscillations periods.

Audience Take Away:

• CA automata based approach is a nice method of choice for complicated system modeling. In particular it correctly reproduces the qualitative features of passivating systems now including the oscillatory behavior.
• It can be used for a range of problems such as surface mask at nanoscale, inflence of aggressive ions on the passive layer structure, depassivation healing etc. It can have potential applications in surface nanosttructuring for subsequent enzyme or another catalyst deposition.

Biography:

Dr J. Stafiej graduated from the Department of Physics, Warsaw University, 1980. In 1991 he defended PhD thesis supervised by prof. Zofia Borkowska, Institute of Physical Chemistry, Warsaw, (ICHF). He collaborated with JP. Badiali in Paris for over 20 years on statistical field theory for interfacial electrolytes. His habilitation thesis concerns branching pattern of differential capacitance caused by ionic profile depletion (ICHF 2002). Since 2014, as a professor in the Institute of Chemistry, Cardinal Stefan Wyszynski University, Warsaw, he works on corrosion, passivation, nanopore formation and oscillatory phenomena within cellular automata approch. He authors 59 SCI papers.