FeNbBP type nanocrystalline alloy with high Bs of 1.64 T optimized by sputtered thin film method

Abstract

The increasing of saturation magnetic flux density (Bs) in FeNbB type nanocrystalline alloy has been widely studied. The influence of additional element to improve Amorphous Forming Ability (AFA) in precursor was investigated using substrate temperature controlled sputtering method at 523K. The AFA was improved by the addition of P, Si, V, or Mo, was decreased by the addition of Y, Cu, or Ge. Especially, the addition of 1 at% P exhibited a good effect of obtaining 85 at% of maximum Fe content with high stable amorphous precursor. The addition of P or C increased Bs. The Fe85Nb6B8P1 nanocrystalline alloy ribbon showed stable amorphous phase as quenched, exhibited a homogeneous nanocrystalline structure composed of grains with 10 to 20 nm in diameter after nanocrystallization. The ribbon exhibited high Bs of 1.64T and low coercivity of 10 A/m.