The Effectof Film Microtexture and Magnetic Field on Transparency of Fe3O4-PDMS Nanocomposite Films

This letter reports the feasibility of tuning the transmittance of Fe₃O₄-polydimethylsiloxane nanocomposite films via film microtexture and external magnetic field. Anisotropic and isotropic films with Fe₃O₄ nanoparticle weight fractions ranging from 1 wt% to 13 wt% were fabricated in the presence and absence of an external magnetic field, respectively, during the film fabrication process. UV-vis transmission spectra of the films indicate that the anisotropic films demonstrate higher transparency than the isotropic counterparts with the same weight fraction of Fe₃O₄ nanoparticles. Furthermore, it was observed that the transmittance of the films can be tuned by applying an external magnetic field, which might be due to changes in the Fe₃O₄ interparticle distance induced by magnetostrictive effect. In the case of an anisotropic film with Fe₃O₄ nanoparticle weight fraction of 10 wt%, the transmittance decreases by 8.61% at the wavelength of 600 nm under a magnetic field of B= ~800 G.