The Effect of Nb Content on the Thermal, Structural, and Magnetic Properties of FeNbB Ribbons

Amorphous $Fe_{80-x}Nb_{x}B_{20}$ (x = 5, 10, 15) ribbons were prepared by single-roller melt spinning method. The thermal, structural and magnetic properties of $Fe_{80-x}Nb_{x}B_{20}$ (x = 5, 10, 15) ribbons were investigated using differential thermal analysis, X-ray diffraction, and vibrating sample magnetometer. The thermal stability is the lowest for $Fe_{70}Nb_{10}B_{20}$ ribbon and the highest for $Fe_{65}Nb_{15}B_{20}$ ribbon. Along with the increase of Nb content, the supercooled liquid region Δ $T_{x}$ increases, indicating that the amorphous formation ability improves. The primary stages of crystallization of the three ribbons are different. The primary devitrification phases are $Fe_{23}B_6$ type for $Fe_{70}Nb_{10}B_{20}$ and $Fe_{75}Nb_5B_{20}$ ribbons, and α-Fe type for $Fe_{65}Nb_{15}B_{20}$ ribbon. $Fe_{80-x}Nb_{x}B_{20}$ (x = 5, 10) ribbons are ferromagnetic and the $Fe_{65}Nb_{15}B_{20}$ ribbon is paramagnetic. The saturation magnetization ($M_{s}$) decreases with increasing Nb content.