Quasiperiodic behavior in the electrodeposition of Cu/Sn multilayers: extraction of activation energies and wavelet analysis

Author(s)

Menezes, Laura ^[1] ; Parma, Eduardo ^[1] ; Machado, Eduardo G. ^{[1, 2]} ; Nagao, Raphael ^{[1, 2]}

Affiliation

^[1] Univ Estadual Campinas, Inst Chem, BR-13083970 Campinas, SP - Brazil

^[2] Univ Estadual Campinas, Ctr Innovat New Energies, BR-13083841 Campinas, SP - Brazil

• Document type: Journal article
• Source: Physical Chemistry Chemical Physics; v. 21, n. 37, p. 21057-21063, OCT 7 2019.
• Web of Science Citations: 0

Abstract

Living systems are one of the many examples in which self-organizing systems yield more intricate structures than those that can be achieved using a ``step-by-step{''} approach. This phenomenon can be observed in electrochemical organic synthesis, oscillating metal deposition and in chemical clocks. There is a plenitude of temporal instabilities during self-organization, from ordinary period-one oscillations, going through quasiperiodicity, to the onset of chaos. Here, we describe the emergence of quasiperiodic behavior during the oscillatory electro-deposition of Cu/Sn. The time-series were characterized using a continuous wavelet transform in order to extract the oscillation frequency of the process with changes in temperature, and to calculate the apparent activation energies. Two different energy ranges are presented, and these are attributed to an activation barrier (similar to 50 kJ mol(-1)) which is closely related to a fast time-scale of the feedback loops responsible for the current oscillations and a diffusional process (similar to 20 kJ mol(-1)), connected to the slow modulations of the oscillation amplitude, giving rise to quasiperiodic dynamics. This kinetic information might provide information on the self-organized synthesis of Cu/Sn metallic multilayers which are kept far from the thermodynamic equilibrium. As self-organization in chemical systems is rapidly developing into a powerful strategy for designing new functional materials, the availability of kinetic parameters is of major interest in rational design. (AU)

• FAPESP's process: 16/01817-9 - Design and control of self-organized electrochemical patterns
• Grantee: Raphael Nagao de Sousa
• Support type: Research Grants - Young Investigators Grants
• FAPESP's process: 17/11986-5 - Research Division 1 - dense energy carriers
• Grantee: Ana Flávia Nogueira
• Support type: Research Grants - Research Centers in Engineering Program