Self-assembled growth and magnetic properties of Fe and FeTiO3 core-Sr (Ti,Fe)O-3 shell nanocomposites

Abstract

In this study, a promising method for the modulation of the microstructure, composition, and magnetic properties of thin films fabricated by co-sputtering metallic Fe and oxide SrTiO3 targets is proposed. The proposed method can potentially be applied in multifunctional electronics. The flat surface morphology was observed in the thin film sputtered under a low power for the Fe target, whereas micro-height rods were fabricated on an uneven layer at a higher power. Strong magnetic anisotropy was not observed in the co-sputtered thin films because of the randomly oriented growth of the magnetic rods. Detailed microstructural and compositional studies using high-resolution transmission electron microscopy and scanning transmission electron microscopy revealed that self-assembled nanocomposites with three components were grown with a core-shell structure, in which Fe and FeTiO3 phases grew in the Sr(Ti,Fe)O3 matrix. This report provides an insight into designing multifunctional metal-metal oxide nanocomposites with single-step co-sputtering, which is capable of adjusting the composition and geometry of the nanocomposites.