抄録
Submicron-sizedparticles of M-type Sr-ferrite were obtained from fine Fe2O3 and precipitated SrCO3. The magnetic properties of the powder were σs=71 emu/g and Hcj=5.5 k0e. The Hcj of the powder was reduced to less than 40% of the initial value by dry vibration milling. SEM observation showed that the primary particle size distribution was not much different from that in the initialstate. Crystal distortion was determined by XRD investigation, using the method of Warren and Averbach. The torque curve of the milled powder was measured by using a highly sensitive torque magnetometer. The dependence of K2/K1 on the measuring magnetic field was increased according to the crystal distortion by milling. The Möessbauer absorption effect was also measured. Submicron particles were analyzed in comparison with coarse Sr-ferrite particles (3μm) by a conventional breaking-down process.
