Exploiting a pronounced photo-magnetic effect over the rational design of facile core–shell ferrowmagnet

Designing artificial nanostructures with well-defined composite and morphology may create magic phenomena that are otherwise unattainable. In this work, we have synthesized a facile core–shell structure with CoFe₂O₄ as the core and Prussian blue analog as the shell (CoFe₂O₄@PBA). By introducing the photo-sensitive shell, this hybrid can perform unexpectedly great changes in saturation magnetization and coercivity under illumination at 5 K. Herein, we contribute this photo-magnetic effect to the valence state transition of Fe ions in CoFe₂O₄, which is induced by the optical-excited electrons transfer from the CoFe PBA shell to the CoFe₂O₄ core.