Bioinspired fabrication of magneto-optic hierarchical architecture by hydrothermal process from butterfly wing

► We develop a green, easy controlled hydrothermal process to synthesize magnetite hierarchical architecture. ► The optical response of Fe3O4/wing exhibits a coupling effect between the structure and material. ► The saturation magnetization value is mediated by shape anisotropy and the stress of different subtle structure, which has provided unique insights into studying the mysterious magnetic property of magnetite.