Shurinovа E. Interparticle magnetic interaction in the different dispersion systems of particles of highanisotropy barium ferrite

The object of research: the system of nano- and microcrystals highanisotropy hexagonal barium ferrite. Objective: To define the magnitude and sign of magnetic interaction parameters resulting in highdensities systems of particles in a wide range of temperature and the magnetic field. Methods: The electron microscopy (transmission and raster), mikrodifraction, X-ray phase analysis and standard magnetic methods in the temperature range 300 - 700 K and in the range of values of the magnetic field 0,5-20 kOe. Results: The obtained data on the magnitude and sign of the parameters resulting interparticle magnetic interactions, depending on the dispersion of particles, the effective magnetic anisotropy and surface physical-chemical condition of the surface plate particles, the magnetic state of particles and their whole surface, temperature and external magnetic field. There are defining the mechanisms of collective effects in highly dispersed systems. Namely, confirmed by determining the role of the magnetic moments of ions in the formation of surface magnitude and sign of the resultant interparticle interaction. A lowfield boundary distribution on the effective magnetic anisotropy field of particles with a volume close to superparamagnetic. For the first time for the system singledomain microcrystals revealed a strong effect of interparticle interaction. Field of use: the magnetic recording technology, the advanced medical-biology technologies.