Thermal stability, magnetic properties and GMI effect of Cr-doping amorphous CoFeSiB ribbons

•Proper amount of Cr is beneficial for stabilizing the amorphous nature of the ribbons.•Optimized Cr content of about 3.5 at.% gives lowest coercivity (∼0.1 A/m) and highest permeability (86,000).•The alloy ribbon with Cr content of 3.5 at.% showed largest GMI value (76%).

The thermal stability, magnetic properties and GMI effect of amorphous Co68Fe7−xCrxSi15B10 (x = 0, 1.5, 3, 4.5) ribbons were investigated in this paper. Thermal analysis results show that the crystallization temperatures of as-prepared ribbons were affected significantly by Cr doping. The saturation magnetization of ribbons decreases with increasing Cr content. Optimized Cr content of about 3 at.% gives lowest coercivity (∼0.1 A/m) and highest permeability (86,000). The maximum GMI value was achieved by optimizing the frequency and amplitude of driving ac current (2 MHz and 10 mA). The ribbon doped with 3 at.% Cr shows largest GMI value (76%) due to magnetic softness.