Remanent magnetization plots of fine particles with competing cubic and uniaxial anisotropies

Magnetization and remanent magnetization curves for noninteracting single-d omain particles whose anisotropy is made up of a cubic magnetocrystalline a nd an uniaxial components were investigated. For a given cubic anisotropy, the saturation remanence, coercivity, remanence coercivity, and coercivity factor values have been obtained for several different uniaxial anisotropy directions. The corresponding delta M plots have been constructed for initi ally thermal or ac demagnetized systems, and a great variety of their shape s has been obtained when the uniaxial anisotropy does not dominate. Coerciv ity factor values rather higher than those for pure uniaxial or cubic aniso tropy particles have been obtained as well, even for already dominating uni axial anisotropy for some uniaxial anisotropy directions. Thus, it has been shown that one may not safely draw conclusions about interactions from dev iations from the zero line in the delta M plots or coercivity factor values for particles with competing anisotropies without specific analysis for an y particular case. (C) 1999 American Institute of Physics. [S0021-8979(99)0 4310-8].