Relationship of Locally Inhomogeneous, Elastic, and Magnetic Fields in Mn–Zn Ferrites

The regularities of changes in the atomic, electronic, and magnetic subsystems in ferrites of variable composition Mn_xZn_yFe_zO₄ related to the formation of clusters differing in the composition of cations are studied using the methods of X-ray diffraction analysis, X-ray spectroscopy, and theoretical physics. Experimentally detected clusters appearing in the X-ray diffraction patterns as a halo are characterized by a certain superposition of ion states, the magnetic moment of which depends not only on the spin of the electron, but also on its orbital moment and the spin of the nucleus. In a mesoscopic cluster structure, a phase transition from manganese-containing clusters stipulated by the interaction of trivalent manganese ions with oxygen ions to clusters with a predominance of divalent and trivalent manganese ions with oxygen ions is discovered. It is found that the clustered structure of manganese-zinc ferrites is responsible for the appearance of extreme magnetic properties; the maximum corresponds to a change in the dominant type of clusters. It is found that with an increase in mass density, a repopulation of energy states occurs: a decrease in the number of states of the low-energy electron group and their increase in the high-energy group in the form of a Fermi-surface saddle point. It is established that the peculiarities of condensation of the basic and soft modes of complexes (clusters) containing manganese and oxygen ions result in changes in the physical parameters of the samples.