Production of Magnetically Soft Submicron Particles From Aqueous Solutions and Characterization

Submicron-size amorphous particles were produced chemically from aqueous solutions. The particles in the as-made state exhibit a high saturation magnetization and magnetic softness almost equivalent to that of much larger amorphous particles produced by water atmizing. Platinum ions work effectively to control the particle size without losing magnetic softness. Magnetic softness observed for the as-made particles becomes degraded slightly by annealing. A calculation of eddy current within spheres predicts no eddy current loss even at 100 MHz for 0.3-mum particles, whereas initial permeability measurements exhibit slight indication of magnetic loss due to the broad spin resonance profile extending from 100 MHz to 10 GHz.