Compositional, structural and magnetic study of layered Co-Mn-O-B deposits formed during potentiostatic electrodeposition exhibiting current oscillations

R. Rashkov, S. Zsurzsa, B. Jóni, M. Arnaudova, I. Bakonyi, L. Péter

Research output: Contribution to journalArticle

Abstract

It was reported previously [Trans. Inst. Met. Finish. 85, 94 (2007)] that during potentiostatic electrodeposition from electrolytes containing a low concentration of Co2+ and Mn2+ ions and boric acid, a layered structure consisting of alternating Co-rich and Mn-O-B-rich zones can be formed. In the present study, electrodeposition was carried out from both sulfamate and sulfate electrolytes. A cyclic voltammetry study was performed for identifying the potential intervals associated with the deposition regimes of the components. The current amplitude data recorded during electrodeposition exhibited a periodic oscillation with a period of 1.9 ± 0.1 s. The fast Fourier transforms of the chronoamperometric data showed two maxima, the ~0.5 Hz peak corresponding to the major oscillation period and the ~1 Hz peak to the first harmonic one. An analysis of the overall deposit composition revealed that the Mn/Co ratio was typically in the range from about 0.05 to 0.25, the sulfamate bath resulting in systematically higher values. The X-ray diffraction patterns of the deposits were dominated by a broad Gaussian peak characteristic of an amorphous phase. The room-temperature magnetization indicated that the deposits contain nanometer-sized magnetic entities with superparamagnetic behavior.

Original languageEnglish
Pages (from-to)D908-D915
JournalJournal of the Electrochemical Society
Volume164
Issue number13
DOIs
Publication statusPublished - Jan 1 2017

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ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Renewable Energy, Sustainability and the Environment
  • Surfaces, Coatings and Films
  • Electrochemistry
  • Materials Chemistry

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