Thermoelastic‐tunable magnetic response of BiFeO3 thin film on colloidal photonic crystal substrate fabricated by pulsed laser deposition

Investigation of the thermoelastic‐tunable magnetic response of polycrystalline bismuth ferrite thin film is herein reported. The polycrystalline bismuth ferrite thin films were grown by room‐temperature pulsed laser deposition on the designed polymer colloidal photonic crystal substrates. The evolution of these films was assessed by X‐ray diffraction testing and scanning electron microscopy images. The thermal‐dependent magnetic measurements and magneto‐optical properties were also investigated as a function of deposition substrate and target–substrate distances via the Faraday rotation method. Due to the large anisotropic thermal deformation of the polymer colloidal interface, the huge rotation downshift was observed versus a slight thermal change. Furthermore, we found that this returnable reduction had the same behavior during the heating and cooling processes. This reversible thermal property of the polymer colloidal crystal in combination with the magnetic response of the multiferroic compounds can possibly lead to innovations in sensors and switches based on thermomagneto‐optical coupling and facilitate the nanoscale thermal characterization.