Evolution of Surface Roughness in Electrodeposited Co–Ni–P and Co–Ni Films

Abstract

Dynamic scaling analysis was applied to the investigation of the roughening kinetics of Co–Ni and Co–Ni–P films electrodeposited from acidic (pH 3) chloride solutions. Co–Ni films exhibit uninhibited growth with the formation of well-defined crystal facets, while Co–Ni–P films exhibit a granular microstructure with a much smaller apparent grain size. Correspondingly, the rate at which Co–Ni–P films roughen is much slower than that of the Co–Ni films. This is ascribed to autocatalytic processes during Co–Ni–P deposition occurring in parallel with electrochemical processes, inducing growth inhibition due to the ongoing nucleation, incorporation of phosphorus, and enhanced hydrogen evolution. The slow roughening of Co–Ni–P films is advantageous for microfabrication processes involving the formation of thick magnetic films and microstructures.

Metal–organic coordinated multilayer film formation: Quantitative analysis of composition and structure

“…The roughness measurement (Rq), found using the commercial image analysis software, represents the average deviation of height from the mean over the entire image area. The Ws roughness measurement is a more rigorous analysis that is able to quantitatively describe surface features (i.e., grain structure size) and permits differentiation between short-and long-range roughness [52][53][54]. The Ws roughness number is determined as a function of area after sampling multiple "box" sizes collected for each image.…”

“…The 3 L sample has a curve that has a sharper increase in roughness indicating that it has a high degree of short-range roughness, while the 30 L sample is smoother over those short ranges. By analyzing these curves, the typical feature (grain) size can be determined [52][53][54]. The grain size is a fit parameter that correlates to the length of the box at which the Ws roughness becomes constant.…”

Morphology and Magnetic Properties of Amorphous Со-P and Co-Ni-P Films

“…Phosphorous atoms do not penetrate inside grains formed by metal atoms but are positioned along their boundaries [5]. This prevents the growth of grains; therefore, their size in the films prepared by chemical deposition is much smaller than in the Со-Ni films prepared by the electrolytic method [6]. At the same time, the rate of autocatalytic reactions ( 1) is different for different metals.…”