Mazurenko Y. Synthesis, structure and physical and chemical properties of nano dispersed magnesium-substituted lithium iron spinel.

The effect of substitution of magnesium on the structure, morphology, electrical and magnetic properties of nanosized lithium ferrite, synthesized by the method of sol-gel autocombustion is investigated in the dissertation. The influence of the conditions of synthesis: pH of the reaction medium and the temperature of post synthesis annealing on the morphology and the physical properties of the synthesized material have been established.As a result of studies by the method of impedance spectroscopy, it has been shown that the conductivity of the synthesized systems is realized by the spin mechanism and, in substitution, from the temperature dominant, the contribution passes from the influence of the grain boundaries and defects on their surfaces at low and room temperatures to iron cations localized in the octopagus of the spinel.It is established that magnetic characteristics increase to the value of replacement x = 0,4, with subsequent replacement, they decrease. This behavior is explained on the basis of the features of the substitution of non-magnetic ions in the spinel sublattice.