Compositional, Structural and Magnetic Study of Layered Co-Mn-O-B Deposits Formed during Potentiostatic Electrodeposition Exhibiting Current Oscillations. Issue 13 (1st January 2017)

• Record Type: Journal Article
• Authors: Rashkov, R.; Zsurzsa, S.; Jóni, B.; Arnaudova, M.; Bakonyi, I.; Péter, L.
• Is Part Of: Journal of the Electrochemical Society. Volume 164:Issue 13(2017)
• Page Start: D908
• Page End: D915
• Publication Date: 2017-01-01
• Subjects: Co-Mn-B-O layered structures -- current oscillation -- structural and magnetic properties; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/2.1881713jes
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : It was reported previously [ Trans. Inst. Met. Finish. 85, 94 (2007)] that during potentiostatic electrodeposition from electrolytes containing a low concentration of Co 2+ and Mn 2+ 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.