Soft-Magnetic Fe-Based Nano-Crystalline Thick Ribbons

Fe-based nano-crystalline thick ribbons (up to 150 mum) with excellent soft magnetic properties were developed in Fe
₇₁
B
₂₂
Ta
_x
Y
_6-x
Ag
₁
alloys (x=1 ~ 5) alloys. The design of these Fe-based alloys was based on a ternary bulk metallic glass (BMG) Fe-B-Y system; Ta and Ag were added to achieve optimal nano-crystallization and to improve soft magnetic properties. An optimal composition Fe
₇₁
B
₂₂
Ta
₅
Y
₁
Ag
₁
was worked out showing good glass forming ability, and sound soft magnetic properties after nano-crystallization at 615
^deg
C for 5 min: saturation magnetization 1.44 T (152 emu/g), coercivity 35 A/m, and effective permeability at 1 kHz higher than 28000. The nanocrystalline Fe
₂₃
B
₆
phase was found to be magnetically soft in these thick ribbons.