Effects of Cu substitution for Fe on the glass-forming ability and soft magnetic properties for Fe-based bulk metallic glasses

• Fully glassy rods of Fe72−xCuxB20Si4Nb4 BMGs were produced above 1 mm in diameter.
• Investigated BMGs exhibit large glass-forming ability and excellent soft magnetic properties.
• Proper Cu substitution improves magnetic properties without obvious deterioration of glass-forming ability.

The effects of Cu substitution for Fe on the glass-forming ability (GFA) and soft magnetic properties for Fe72−xCuxB20Si4Nb4 (x=0.0, 0.2, 0.4, 0.6, 0.8, and 1.0) bulk metallic glasses (BMGs) are investigated. It is found that the investigated BMGs exhibit large GFA as well as excellent soft magnetic properties, and proper substitution of Fe by Cu improves the saturation magnetization, coercive force, and effective permeability without obvious deterioration of the GFA.