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Geng T, Zeller SJ, Kibler LA, Ceblin MU, Jacob T. Electrodeposition of Cu onto Au(111) from Deep Eutectic Solvents: Molar Ratio of Salt and Hydrogen Bond Donor. ChemElectroChem 2022. [DOI: 10.1002/celc.202101283] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Tanja Geng
- Institute of Electrochemistry Ulm University Albert-Einstein-Allee 47 89081 Ulm Germany
| | - Sven J. Zeller
- Institute of Electrochemistry Ulm University Albert-Einstein-Allee 47 89081 Ulm Germany
- Helmholtz-Institute Ulm (HIU) for Electrochemical Energy Storage Helmholtzstr. 11 89081 Ulm Germany
- Karlsruhe Institute of Technology (KIT) P.O. Box 3640 76021 Karlsruhe Germany
| | - Ludwig A. Kibler
- Institute of Electrochemistry Ulm University Albert-Einstein-Allee 47 89081 Ulm Germany
| | - Maximilian U. Ceblin
- Institute of Electrochemistry Ulm University Albert-Einstein-Allee 47 89081 Ulm Germany
| | - Timo Jacob
- Institute of Electrochemistry Ulm University Albert-Einstein-Allee 47 89081 Ulm Germany
- Helmholtz-Institute Ulm (HIU) for Electrochemical Energy Storage Helmholtzstr. 11 89081 Ulm Germany
- Karlsruhe Institute of Technology (KIT) P.O. Box 3640 76021 Karlsruhe Germany
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Leimbach M, Tschaar C, Schmidt U, Bund A. Low-frequency pulse plating for tailoring the optical appearance of chromium layers for decorative applications. J APPL ELECTROCHEM 2020. [DOI: 10.1007/s10800-020-01406-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Abstract
The optical appearance of electroplated chromium layers is a crucial factor for decorative applications. Currently in the decorative chromium plating industry the so far used hexavalent electrolytes are being replaced progressively by solutions of trivalent chromium. However, chromium deposited from trivalent baths tends to have a yellowish color hue at thicknesses beyond 100 nm, which is undesired for most applications. The shift in color is related to a change in surface morphology due to the globular growth of the chromium nuclei. By utilizing pulsed current with on-times in the range of seconds, the grain growth is suppressed and the formation of fresh nuclei is favored. As a result, the average grain size of the layer can be decreased significantly. Compact chromium layers with small grains and improved color values are formed. A blueish appearance and high brightness were maintained up to thicknesses of more than 200 nm. Based on the results a combination of constant and pulsed current is suggested, yielding similar visual appearance as in the case of pulsed current only, but reaching the targeted film thickness much faster.
Graphic abstract
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