Analysis of the magnetic anisotropy in advanced metal particles for recording media

The magnetic anisotropy of metal particles with high coercivity, useful in the recording technology, is investigated with measurements of the anisotropy distribution, as obtained from the second derivative of the perpendicular magnetization, and of the transverse susceptibility. Also the temperature dependence of the magnetic properties is studied at the same aim. The relevance of shape anisotropy, and therefore of the particle morphology, in determining the magnetic behavior of the advanced metal particles is expressed. The effect of the particle-particle interactions on anisotropy is studied in aligned samples with different packing densities. The average anisotropy field does not change with packing, which on the contrary affects the width of the anisotropy distribution, which is larger in packed samples, because of the diversified contributions of the interacting particles. © WILEY-VCH Verlag Berlin GmbH.