Magnetic domain structure and anisotropy distribution in Al/Metglas 2605S2/Al trilayers

Abstract

Al coatings, with thickness (x) up to 20 µm, were deposited by dc sputtering on both sides of the Metglas 2605S2 precursor melt-spun ribbons. Spin reorientation, induced by the magnetoelastic effect, was clearly observed in the Al/Metglas 2605S2/Al trilayers by monitoring the 2 and 5 line intensities of the Mössbauer spectra obtained at different temperatures. The average spin orientation angles can be controlled by adjusting the Al thickness. A magneto-mechanical coefficient, which measures the rate of spin reorientation with respect to the temperature variation, was obtained and is found to be equal to −0.15 • K −1 and −0.28 • K −1 for x = 5 µm and 20 µm, respectively. Using a spin structure phenomenological model, in-plane native magnetic anisotropies ranging up to 3 kJ m −3 were estimated for the Metglas 2605S2 ribbons. Energy anisotropy values higher than 20 kJ m −3 are associated with inhomogeneities and defects from the sample preparation method and may correspond to about 10% of the ribbon volume.