Nanostructure and oxide phase distribution in Co36-40Fe64-60 electrodeposited films for magnetic field sensors

Abstract

Co36-40Fe64-60 films were electrodeposited on Cu/Si substrates from electrolytes containing variable amounts of Fe3+, to control the film’s oxygen content. The films were body centered cubic with grain sizes of 10 to 20 nm. Analytical electron microscopy was used to determine oxygen distributions and bonding states in the films. Intergranular trivalent Fe2O3 was distributed along grain boundaries in the films with highest oxygen content. A lower volume fraction of intragranular FeO particles were observed in low oxygen content films. Intergranular Fe3+ oxide increased the coercivity and magnetoresistance and reduced the mass saturation magnetization relative to the low oxygen content films.

Aberration-Corrected STEM Study of Magnetic Alloys

“…Previously, we have shown [1,2,3] Z contrast images of nanodistributions of different Fe oxides in nanocrystalline room temperature electrodeposited Co 40 Fe 60 films and corresponding energy dispersive (EDS) and electron energy loss (EELS) spectra recorded at 200 keV in an uncorrected JEOL 2010F. The objective was determination of oxygen distribution, valence state and crystallinity which affect the film's magnetic properties.…”