Magnetic relaxatio in aligned Fe_3O_4 fine particles

摘要

The remanent magnetization of aligned Fe_3O_4 fine particles with median diameter (D approx approx 121 A) has been measured in the temperature range 85<=T<=290K and in time up to t=500 Sec. The remanent magnetization parallel to the aligned direction was found to be systematically higher than that for the perpendicular to the aligned direction. The time decay of the remanent magnetization of aligned Fe_3O_4 fine particles was found to be logarithmic within the measuring period. The coefficient of magnetic viscosity was determined. The data was found to agree with the Tln (t/#tau#_0) scaling plot for the two directions.