Applied Surface Science, Vol.317, 294-301, 2014
An investigation of ruthenium coating from LiCl-KCl eutectic melt
In this study, electrodeposition of ruthenium (Ru) from LiCI-KCI eutectic melt was investigated in a systematic manner and the effects of process parameters namely current density, time and agitation of electrolyte on the thickness and morphology of Ru layer were explored. The presence of Ru on graphite substrates was confirmed by thin film X-ray diffraction method. The Ru coatings formed at all electrodeposition conditions appeared as a white/gray deposit. The typical "faceted structure" was observed on the surface of Ru deposited at 3 and 7 mA/cm(2). Fracture cross-section examinations revealed the columnar morphology of Ru which was twinned with boundaries. The smooth appearance of Ru coating became uneven and rough with coarse nodules at 12 mA/cm(2). The thickness of Ru increased with increasing both current density and time at stationary electrodeposition conditions. A dense and 7.5 pin thick Ru coating was possible to grow on graphite without any agitation at 3 mA/cm2 for 2 h. The highest cathodic current efficiency OA 99.68%, was achieved at 3 mA/cm2 after 2 h of electrodeposition time with the rotating cathode speed of 50 rpm. The cross sectional micro-indentation studies indicated that the Ru layer has hardness as high as 450 + 10 HV. (C) 2014 Elsevier B.V. All rights reserved.