Micromagnetic structure of Co-rich amorphous microwires

Results on the magneto-optical investigation of near-surface micromagnetic structure (MMS) of Co69Fe4Si12B15 amorphous wires 10 similar to 50 mu m in diameter are presented. The wires were prepared by the rapid solidification technique. The magnetic field H was applied along or perpendicular to the wire length. By scanning the light spot of 1 mu m-diameter along the wire l ength, distributions of magnetization components (both parallel and perpend icular to the applied magnetic field) and also local hysteresis characteris tics of the wires were measured. It was experimentally established that owi ng to the compressive stresses from quenching coupled with negative magneto striction of Go-rich amorphous materials, the examined microwires have a ci rcumferential magnetic anisotropy. In consequence, there are the near-surfa ce alternate left- and right-handled circular domains in these samples. The dependencies of the circular domain width on the wire diameter and length were found. It was discovered that in the axial magnetic field local hyster esis loops are unhysteretic. It was proved that in this case the dominant m echanism of the wire magnetization reversal is rotation of local magnetizat ion vectors in circular domains.