Large magnetic permeability and resonant frequency of CoFe nanofilms electrodeposited via optimizing plating solution parameters based on electrochemistry mechanisms

摘要

A simple methodology to electrodeposit thin soft CoFe films with desirable microwave properties from simple salt solutions at room temperature is demonstrated. Plating solution parameters have diverse influences on real potentials of ion reductions and deposition behavior of the FeCo crystals, consequently affecting largely the particle size, crystal structure and chemical composition of the film fabricated. This in turn determines their static magnetism and dynamic microwave properties. Through optimizing solution additive, concentration and temperature from electrodeposition mechanism, the as-prepared nanofilms possess a low coercivity of < 30 Oe, moderate anisotropy of 60-90 Oe, high crystallinity and magnetic moment of ≥ 2.0 T, and hence readily display an ultrahigh magnetic permeability (up to 1128) and resonant frequency (up to 2.1 gigahertz) simultaneously, as well as other desirable physico-chemical properties. Thus the nanofilms can be applied to high gigahertz frequency applications.