Study of structural features and phase transformations in nanocomposites of Fe_2O_3@NdFeO_3 type

摘要

The aim of this work is to study the effect of the Nd_2O_3 dopant concentration on the phase composition, structural, and magnetic parameters of Fe_2O_3@NdFeO_3-type nanocomposites, which have great prospects for use as a catalyst base for the purification of aqueous media from heavy metals. Using X-ray phase analysis, it was found that an increase in dopant concentration leads to the formation of a stable NdFeO_3 phase, which dominates in the structure at concentrations of 0.4-0.5 mol. Changes in the structural parameters, as well as the density of nanocomposites, are associated with structural orderings arising as a result of phase transformations and NdFeO_3 phase dominance in the structure. Using Mossbauer spectroscopy, it was found that values of the hyperfine magnetic parameters are characteristic of the hematite structure, while, according to the data obtained, the presence of paramagnetic inclusions was not observed. Evaluation results of the manganese purification efficiency of aqueous media showed that an increase in particle concentration from 0.001 to 0.005 g leads to an increase in absorption efficiency to 45-75%, which indicates a positive effect of absorption and degree of purification.