The structure and microwave permeability of thin cobalt films

Abstract

An increase in the ferromagnetic resonance frequency from 3 to 5.5 GHz is discovered in thin Co films during an increase in the crystallite size from 6 to 70 nm. The structure change is achieved by increasing the deposition rate from 4.2 to 7.1 nm/min in direct current magnetron sputtering. The Co films possess a uniaxial crystallographic texture. The orientation of the texture axis varies with a variation in deposition parameters, which causes changes in the in plane magnetic anisotropy. A model to describe the discovered changes is proposed.