The composition, structural features, surface morphology, roughness parameters, particle size, and magnetic features of nanostructured Fe-Co-Ni deposits manufactured on conducting indium tin oxide-coated glasses at various electrolyte pH values are studied. The deposit produced at low electrolyte pH contains slightly higher Fe and Co contents but lower Ni content compared to deposits fabricated at high pH values. Further composition analysis confirms that the reduction rates of Fe2+ and Co2+ are higher than the Ni2+ reduction rate. The films consist of nano-sized crystallites with a strong [111] preferred orientation. The results also reveal that the crystallization of the thin films is affected by the electrolyte pH. Surface analysis shows that the deposit surfaces are composed of nano-sized particles with different diameters. The mean particle diameter and surface roughness decrease as the pH of the electrolyte decreases. The effect of the electrolyte pH on the morphology is also discussed in terms of surface skewness and kurtosis parameters. Magnetic analysis shows that the resultant deposits have in-plane hysteresis loops with low and close SQR parameters ranging from 0.079 to 0.108. The results also reveal that the coercive field of the deposits increases from 29.4 Oe to 41.3 Oe as the electrolyte pH decreases from 4.7 to 3.2.
Keywords: coercive field; electrolyte pH; hydrogen evolution; nanostructured Fe-Co-Ni deposits; roughness parameters.
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