Formation mechanism, thermal and magnetic properties of (Bi(1-x)Sr(x))(m+1)Fe(m-3)Ti(3)O(3(m+1)-δ) (m = 4 – 7) ceramics

Abstract

Specific features of the formation of Aurivillius phases (Bi 1−x Srx) m+1 Fe m−3 Ti 3 O 3(m+1)−δ (m = 4 − 7; x = 0.0 − 0.7) with a perovskitelike block having a nanometric thickness (h) of 2-3 nm are described. It has been established that the degree of isomorphous substitution in the bismuth sublattice and thermal stability of phases tend to reduce with the increasing h. It has been demonstrated that the magnetic ions inside the perovskite-like block can have antiferromagnetic interaction exchange that influences magnetic properties of the Aurivillius phases.

Fractal characterization of nanostructured materials

“…The high specific surface area of fractal aggregates of different nature explains the possibility of their active participation in condensation processes, sorption processes, chemical reactions of heterogeneous catalysis and inhibition, and other applied areas [13]. Establishing the characteristics of these dependencies allows us to link the indicators of structural and phase nonuniformity in the development of new materials with changes in their physicochemical properties, as well as predicting the effect of the size of the fractal object and the spatial scale of its consideration [14][15][16][17][18][19][20].…”