Thermal and magnetic properties of melt-spun Co-Fe-B-Si-(Cr/Ta) amorphous alloys

Abstract

The ferromagnetic amorphous alloys Co-Fe-B-Si-Cr and Co-Fe-B-Si-Ta were systemically investigated. [(Co1-x Fe (x) )(0.75)B0.2Si0.05](96)Cr-4 (x = 0, 0.1, 0.4, 0.7, 1.0) and [(Co1-x Fe (x) )(0.75)B0.2Si0.05](96)Ta-4 (x = 0, 0.1, 0.3, 0.5, 1.0) ribbons were prepared by using the melt-spinning technique. Amorphous structures were confirmed by the presence of a broad and halo peak in X-ray diffraction (XRD). The thermal characteristics, such as the glass transition temperature (T (g) ), the crystallization temperature (T (x) ) and the supercooled liquid region (Delta T (x) = T (x) - T (g) ), were measured by means of a differential scanning calorimeter (DSC). For the Co-Fe-B-Si-Cr alloys, the values of Delta T (x) were in the range of 51.6-61.4 K, and for Co-Fe-B-Si-Ta alloys, they were in the range of 39.3-55.5 K. The magnetic properties were examined by means of a vibrating sample magnetometer (VSM) at a maximum field strength of 3000 Oe. These glassy ribbons exhibited soft magnetic properties. The saturation magnetization (M (s) ) and the coercive force (H (c) ) were in the ranges of 307.85-854.52 emu center dot cm(3) and 0.64-0.89 Oe, respectively.