CoFe2O4@BiFeO3 core/shell nanoparticles: Synthesis, characterization, and fingerprints of the spin disorder

We synthesize CoFe2O4@BiFeO3 core/shell nanoparticles by coprecipitation and systematically investigate the structural, morphological, and magnetic properties in such nanostructured system. Through structural and morphological characterization, we demonstrate the obtainment of core/shell nanostructure with pure phases. By performing a broad experimental magnetic analysis, we evaluate the magnetic response for the precursor phases, as well as for the core/shell nanostructure. For this latter, we identify fingerprints of the wasp-waisted behavior and exchange bias effect, disclosing the exchange coupling between the phases taking place at the interface. Further, we reveal the exchange coupling between core and shell is strongly affected by a spin glass behavior arisen from the spin disorder in the CoFe2O4@BiFeO3 core/shell nano particles. After all, our findings allow us to place the used procedures taking into account the coprecipitation and calcination processes as a feasible route to the production of high-quality core/shell nanostructures. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

The CoFe2O4@BiFeO3 core/shell nanoparticles were synthesized using coprecipitation, with structural, morphological, and magnetic properties thoroughly investigated. The study revealed a core/shell nanostructure with pure phases, magnetic response characteristics, and spin glass behavior in the nanoparticles, demonstrating the feasibility of the coprecipitation and calcination processes for producing high-quality core/shell nanostructures.