Magnetic Properties of Fe-Co Alloy Fine Particles

Abstract
Fine particles of Fe-Co alloys, whose radii ranged about from 50 Å to 350 Å, were prepared by evaporation in the atmosphere of argon gas at low pressure. They arranged like a necklace. An assembly of these particles, whose average radius was 350 Å, has a uniaxial magnetic anisotropy of 3∼4×106 ergs/cm3, which is mainly due to the shape anisotropy of the assembly. Relative change of magnetization of these particles against the alloy composition was almost the same with the Slater-Pauling curve, but values of magnetization were fairly less than those of bulk specimens. Superparamagnetic behavior was not observed for the assembly of the smallest particles.