Exploring thickness-dependent structural, chemical and magnetic properties of nanostructured nickel thin films

Nickel thin films were deposited to the different thicknesses onto glass substrates using electron-beam glancing angle deposition. The changes in the structural, chemical, and magnetic properties of the films have been investigated. The obtained morphological and microstructural results revealed that the deposited samples consisted of vertical columns with a thickness in the range of 50 nm to 140 nm and a diameter of 15 nm to 29 nm. With the increase in film thickness, the surface roughness increases as well. Chemical analysis showed that the main phase in the samples is metallic Ni, with a certain amount of NiO. In addition, magnetic measurements exhibit that all Ni films show typical hysteresis loops with a uniaxial magnetic anisotropy. The coercivity was found to increase with the thickness up to 110 nm followed by its further decrease, probably due to the differences in the structure of the columns themselves as well as the combined contributions of two different antiferromagnetic (NiO) and ferromagnetic (Ni) phases created in the deposited nanostructures.