Nanoscale Topography and Magnetic Structure of Nanocrystallized Nickel Electrodeposits

Abstract

The microstructure and magnetic properties of nickel films thick of 100 till 1000 nm are here investigated. They are deposited on polycrystalline Cu substrate by cathodic voltammetry (CV) technique varying the scan rate in the interval 0.17 ≤ r ≤ 1.67 mV/s. Thicker and rougher samples grow at lower r values while thinner and smoother ones are obtained at the higher r values. All the samples obtained exhibit a negative strain indicating a compressive stress that decreases with the film thickness increase. The magnetic reversal of the Ni films is ruled by the spin rotation mechanism associated with their low squarness of about 28%. The study of their ferromagnetic-topography dependence reveals that their magnetic domains always remain of the Néel type (MD)_N in the investigated r values according to the model of Zhao et al. [J. Appl. Phys. 89, 1325(2001)]. The magnetic anisotropy of the Ni samples exhibit a out-of-plane component that becomes sensitively marked with the increase of the film thickness.