High magnetic moment in Fe87B11Au2 ribbons

Amorphous Fe87B11Au2 ribbons that are stable above 300 K displayed saturation magnetization M/sub s/ of 223 emu/g at 4.2 K. The deduced average Fe atomic moment mu-bar/sub Fe/ was 2.46 μ/sub B/, which is relatively high compared to mu-bar/sub Fe/ = 2.13 μ/sub B/ in Fe87B13. The higher Fe moment is attributed to a quenched-in, high-volume Fe lattice (similar to that found in amorphous Fe-Au films) stabilized by Au and B atoms. Upon annealing, three crystallization stages were observed. First, a α-Fe phase with about 3 at.% Au emerged at around 620 K followed by a Fe2B phase at roughly-equal745 K. At roughly-equal790 K, a Au-rich phase emerged. There were decreases in M/sub s/ (4.2 K) as the isothermal annealing temperature was increased, with the largest decrease coinciding with the precipitation of Fe2B