STUDY OF PHASE FORMATION IN FE2O3-ND2O3→NDFEO3/FE2O3 NANOCOMPOSITES AS A RESULT OF THERMAL ANNEALING

Abstract

The aim of this work is systematic study of the thermal annealing effect on the preparation of nanostructured composites NdFeO3/Fe2O3 with a spinel type structure. The interest in these nano­composites is due to the enormous potential of their application as a basis for magnetic devices, catalysts, and magnetic carriers for targeted drug delivery. As a synthesis method, two­stage syn­thesis was used, which includes mechanochemical grinding of nanopowders Fe2O3 and Nd2O3 in a planetary mill, followed by thermal annealing of the resulting mixture in a wide temperature range: 600­1000°C. During the studies carried out, it was found that in the initial state the obtained nano­composites are a mixture of a solid solution of interstitial and substitutional Fe2O3 and Nd2O3. At an annealing temperature of 600°C, the onset of the formation of the NdFeO3 phase is observed, which at a temperature of 1000°C is fully formed and dominates in the composite structure (content more than 85%). It was also found that during thermal sintering, the processes of phase transformations of the Fe2O3­Nd2O3→NdFeO3/Fe2O3 type are accompanied by an increase in the particle size by a factor of 1.5­2