화학공학소재연구정보센터
Journal of the Electrochemical Society, Vol.164, No.13, D908-D915, 2017
Compositional, Structural and Magnetic Study of Layered Co-Mn-O-B Deposits Formed during Potentiostatic Electrodeposition Exhibiting Current Oscillations
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 similar to 0.5 Hz peak corresponding to the major oscillation period and the similar to 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. (c) 2017 The Electrochemical Society. All rights reserved.