FeSiBP metallic glasses with high glass-forming ability and excellent magnetic properties

Novel Fe-rich Fe-based bulk glassy alloys with unusual combination of high saturation magnetization (Js) and high glass-forming ability (GFA) have been developed. The representative Fe76Si9B10P5 (atomic percent) alloy exhibits with high Js of 1.51 T, comparable to the Fe–Si–B amorphous alloy ribbons with thickness of about 25 μm in now practical use, because of without any glass-forming metal element other than Fe, which significantly decreases Js, as well as high GFA leading to a rod-shaped specimen of 2.5 mm in diameter. This bulk glassy alloy also shows extremely low coercivity of 0.8 A/m at a glassy state with a higher degree of atomic density of dense random packed structure by optimum annealing. Therefore, the alloy composed of familiar elements with the excellent properties and low material cost should have a great advantage for engineering and industry, and also make a contribution to conservation of environment and earth resources.