Magnetic, Magnetoimpedance and Magnetoresistance Studies in Co-Rich Ribbons

Effects of the different types of annealing (conventional, stress and Joule) on the magnetoimpedance (MI), AC magnetoresistance (ACMR), DC magnetoresistance and magnetic properties of melt-spun Co68Mn5Si12B15 ribbon have been investigated. The MI and magnetic force microscopy (MFM) studies indicate the presence of transverse domains in the ribbon. The magnetization data show smaller coercivity and larger saturation magnetization in case of stress annealed ribbons. For the DC magnetoresistance studies, both transverse (TMR) and longitudinal MR (LMR) are measured. The values of LMR and TMR are found to be positive and negative respectively. Ferromagnetic anisotropy resistivity (FAR) is also investigated in the as-cast and annealed ribbons. Strain induced transverse anisotropy resulted in large MI, ACMR and FAR values in the stress annealed ribbons.