Among many kinds of bulk metallic glasses (BMGs), Fe-based BMGs with good magnetic properties, high strength and low materials cost should have great potential for wide variety of applications. However, the glass-forming metal elements such as Al, Ga, Nb, Mo, Y and so forth in the Fe-based BMGs significantly decrease saturation magnetization (J_s) which is a essential property as soft magnetic materials and also increase the material cost.
The coexistence of high Fe content and high glass-forming ability (GFA) has been earnestly desired from academia to industry. We report a novel Fe₇₆Si₉B₁₀P₅ (at%) bulk metallic glass with unusual combination of high J_s of 1.51 T due to high Fe content and high GFA leading to a glassy rod with a diameter of 2.5 mm despite not-containing any glass-forming metal elements. This alloy composed of familiar and low-priced elements, also exhibiting very excellent magnetic softness and rather high strength, has a great advantage for engineering and industry, and thus should make a contribution to conservation of earth resources and environment through energy saving.