Photoexcitation-Controllable Magnetization in Magnetic–Semiconducting Nanohybrid Containing γ-Fe₂O₃–Graphene (0D–2D) van der Waals Heterostructure Based on Steady-State Pump–Probe Light Scattering Measurement in Magnetic Field

Abstract

This paper reports photoexcitation-enhanced magnetization in γFe2O3–graphene (zero dimensional–two dimensional) van der Waals heterostructure based on the experimental studies of steady-state pump–probe measurements in magnetic field. It is observed that applying a magnetic field on the γ-Fe2O3/graphene material suspended in an organic solvent can cause a light scattering on the probe beam in the absence of pump beam, leading to a magnetic field effect of light scattering. This result shows that the magnetization on the γ-Fe2O3 nanoparticles can lead to a partial orientation of Fe2O3–graphene heterostructure components suspended in liquid. This effect of magnetic field on light scattering is caused by the dynamic magnetization of the superparamagnetic–semiconducting hybrid material. Interestingly, applying the pump beam functioning as photoexcitation can lead to an enhancement on the scattering of probe beam, increasing magnetic field effect of light scattering. The increased magnetic field effect of light scattering indicates that the photoexcitation from the pump beam applied to the hybrid enhances the magnetization on the γ-Fe2O3 nanoparticles through the d−π electron coupling between γ-Fe2O3 and graphene in the hybrid material. This d−π electron coupling can be a practical method to develop photoexcitation-controllable magnetization through excited states based on chemically linked magnetic–semiconducting hybrid design.