Synthesis and Comparison of the Magnetic Properties of Iron Sulfide Spinel and Iron Oxide Spinel Nanocrystals

摘要

The iron—sulfur system contains a number of phases possessing complex and interesting chemical, magnetic and electronic properties, including Fe3S4, which is isostructural to the iron oxide spinel phase Fe2O4. Submicrometer Fe3S4 nanoparticles occur in nature as magnetosomes in magnetotactic bacteria, and as inclusions in geological sediments, where they are significant contributors to chemical remnant magnetization (CRM). Yet the synthesis of monodisperse Fe3S4 nanocrystals and the study of their magnetic properties have received relatively little attention compared to well-researched Fe and Fe3O4 nanocrystals. This is mainly due to the relatively narrow range of thermal stability of Fe3S4 and the tendency for formation of mixtures of iron sulfide phases making the synthesis of phase-pure, crystalline, monodisperse Fe3S4 nanocrystals highly challenging.