Enhanced glass forming ability of Fe-based amorphous alloys with minor Cu addition

•A novel approach for enhancing GFA of Fe-based amorphous alloys is proposed.•Fe-based alloys with high saturation magnetization and good GFA were developed.•The crystalline phases competing is beneficial for GFA was confirmed.

A novel approach was reported that allows us to enhance glass-forming ability (GFA) of Fe-based amorphous alloys with high saturation magnetization by minor substitution Cu, which has a large positive heat of mixing and similar atomic radius with the main constituent Fe. The minor Cu substitution (< 1 at.%) can substantially increase the GFA of Fe-based amorphous alloys with the primary phase that is not α-Fe (110) type phase. Using this strategy, Fe-based amorphous alloys with both high saturation magnetization and good GFA were developed. Our results reveal that the formation of competing crystalline phases is beneficial for the GFA. We anticipate that this work may guide the way for designing new Fe-based amorphous alloys with high saturation magnetization and large GFA concurrently.