The role of strain on the magnetic properties of confined Fe3O4 nanocrystals in Al2O3 matrix

Abstract Dispersing nanocrystals in solid state matrix is a practical way for the applications in nanodevices, which can yield production of non-agglomerated nanocrystals with good magnetic properties. In this work, Fe 3 O 4 nanocrystals in non-magnetic Al 2 O 3 matrix are synthesized by one-step method. HRTEM analyses confirm the formation of chemical stable Fe 3 O 4 nanocrystals. The finite element calculations and Raman spectra demonstrate that the Fe 3 O 4 nanocrystals experience compressive strain from Al 2 O 3 matrix. Typical magnetic behaviors of weakly interacting Fe 3 O 4 nanocrystals are observed, which are characterized by superparamagnetism. Moreover, the influence of strain on their magnetic properties of the Fe 3 O 4 nanocrystals are also investigated. By utilizing the strain engineering, it paves the ways for the applications of Fe 3 O 4 nanocrystals in magnetic nanodevices.