New microcrystalline hard magnets in a Co-Zr-B alloy system

Abstract

The glass formability and magnetic properties of rapidly solidified Co-Zr-B alloys were investigated in the composition range Co/sub 80/Zr/sub x/B/sub 20-x/ (2<or=x<or=18 a/o) in order to determine the glass-forming range and explore the magnetic characteristics as a function of composition and quenching rate. The alloys were found to be completely glassy for 6<or=x<or=10, whereas all the other compositions studied were completely or partially crystalline. The typical glassy alloys showed good soft magnetic properties. The crystalline alloys with Zr content of 16 and 18 a/o were characterized by coercive force in excess of 3 kOe. Slowly-cooled samples of the same composition showed coercivity on the order of 100 Oe.<<ETX>>