Mössbauer Studies of the Structure of Core/Shell Fe<inf>3</inf>O<inf>4</inf>/γ-Fe<inf>2</inf>O<inf>3</inf> Nanoparticles

Abstract

© 2019, Pleiades Publishing, Ltd. Abstract: The phase composition, the structure of cores and shells, and the dependences of the shell thickness on the fabrication technique were determined by Mössbauer spectroscopy for core/shell Fe3O4/γ-Fe2O3 magnetic nanoparticles (MNPs) with Fe3O4 cores of a fixed size (8 nm) and γ-Fe2O3 shells of a varying thickness (1, 3, or 5 nm). A layer on the MNP surface with a magnetic state differing from that in the bulk was found. It was also found that a spin-glass state probably exists between the core and the shell. The studied core/shell Fe3O4/γ-Fe2O3 MNPs have promising applications in various fields (e.g., biomedicine).