Physical and technological principles of creating biocompatible superparamagnetic particles.

Nanodisperse powder of zinc-substituted magnetite has been developed. Functional characteristics (biocompatibility, dispersion, magnetic state) allow to recommend it for approbation in medical and biologic technologies. The character of the temperature dependences of magnetization investigated in the magnetic fields lower than the anisotropy field indicates that transfer from the magnetically stable state into the super- paramagnetic state was realized for particles of 3n13 nm in the temperature range of 4.2n150 K. It reflects specificity of small particles magnetism.