Magnetization Reversal in Cobalt Nanocolumn Structures Obtained by Glancing Angle Deposition

Abstract

An advanced deposition technique known as glancing angle deposition was used to fabricate randomly seeded magnetic cobalt columnar nanostructures. The existence of nanocolumns was con rmed by the cross-section scanning electron microscopy. The evolution in the magnetization reversal mechanism as a function of the lm thickness was investigated. The coercivity HC and MR/MS ratio (where MR and MS denote the remanent and saturation magnetization, respectively), derived from the magnetic hysteresis loops, are discussed as a function of the angle between the external magnetic eld and the surface normal. The direction of the magnetization easy/ hard axis and the columns inclination angle were determined on the basis of the angular dependences of the HC and the MR/MS. A crossover from the coherent rotation, based on the Stoner Wohlfarth model, to the curling reversal mode was observed.