Study of Multicomponent Magnetic Nanostructures with Digital Image Processing Technique.

Abstract

ABSTRACTPreviously, we used Digital Image Processing (DIP) to explore the relationships between the growth morphologies of sputtered two-phase nanostructures and their soft magnetic properties [1]. In this work we extended the application of DIP to analyse the effects of deposition parameters and annealing conditions on their soft magnetic properties including disaccommodation.Magnetically soft, amorphous Co61B39 thin films, exhibiting a two-phase structure, were deposited by sequentially co-sputtering cobalt and boron. We digitized TEM micrographs of these thin films, prepared under different deposition conditions, and subjected to various post deposition processing. Digital Fourier transforms of the TEM micrographs were studied for evidence that the film anisotropy could be correlated with morphological order arising from long and short range interactions between particles over distances of ≈ 0.2 − 1.0 nm.Our qualitative studies showed that important changes in soft magnetic properties were associated with changes in the two phase morphologies. We determined, for example, that specific morphological changes were associated with the reduction in the magnetic anisotropy produced by annealing. In general, decreases in anisotropy were associated with increased isotropy in Fourier space. The largest reductions and circular symmetric 2D Fourier transforms were produced by rotating field annealing.