Out-of-plane anisotropy and low field induced magnetic domain reorientation in Al/Metglas-2605S2/Al trilayer sensors

Abstract

Local magnetism of Al/Metglas-2605S2/Al trilayer-like sensors prepared by dc sputtering has been studied at room temperature by both in-field and zero-field Mössbauer spectroscopy for a maximum field of 60 mT. Ferromagnetic domain reorientation from out-of-ribbon plane to in-plane, induced by low applied fields, was measured by monitoring the intensities of lines 2 and 5 in the Mössbauer sextet spectra obtained for different magnitudes of applied magnetic field. Coating the Metglas-2605S2 with Al layers of 20 μm thickness, a stress-field is induced, allowing to distinguish different in-plane magnetic anisotropy distributions along the ribbon length (∼4 mT) as well along its width (∼10 mT). Using a phenomenological model for the magnetization reversal, out-of-plane anisotropies ranging up to 3 kJ/m3 were estimated for the Metglas-2605S2 alloy ribbons. This anisotropy range is similar to that observed for the in-plane case previously reported. The methodology applied in this work can be used to determine native out-of-plane anisotropy distributions for different melt-spun ribbons. It also allows understanding magnetization reversal associated with the ferromagnetic domains reorientation caused either by induced stress or by applied magnetic field.