Magnetic and transport properties of nanocrystallizing supercooled amorphous alloy Fe74Al4Ga2P11B4Si4Cu1

A new multi-element amorphous alloy Fe74Al4Ga2P11B4Si4Cu1 with large glass forming ability is studied by magnetization and electrical resistivity measurements. During a first crystallization stage, the bcc Fe(Si) grains with mean diameter of 10 nm precipitate inside the amorphous matrix. The nanocrystalline fraction is estimated to be 20%. Nanocrystallization suppresses the magnetic anisotropy and remarkably improves soft magnetic properties—increasing saturation magnetization from 0.9 to 1.4 T and diminishing the coercive force from 14 to 1.8 A/m. This alloy is a very promising precursor for high frequency devices due to the high electrical resistivity reducing the losses. The influence of grain boundaries and Si content on the unusual electrical resistivity behavior is discussed.