Magnetization of electrodeposited nickel: Role of interstitial carbon

Abstract

The magnetization of nickel foils electrodeposited under different conditions was not usually found to differ significantly from that of the bulk (55.4 A m2 kg−1). However, some galvanostatically deposited films from a citrate-based electrolyte showed a lower magnetization, which was rose to the bulk value after annealing at 575 K, with no change in lattice parameter. Analysis of the influence of various lattice defects (nickel vacancies or interstitials, hydrogen or carbon impurities) using density functional theory indicates that nickel vacancies may be present in all of the films and that a nonequilibrium concentration of carbon interstitials is the likely explanation of the reduced magnetization in the citrate as-deposited nickel.