Gigantic magneto-optical effects induced by (Fe/Co)-cosubstitution in titania nanosheets

摘要

Magneto-optical Faraday effect has been investigated for 3d-transition-metal-substituted titania nanosheets Ti_(1-x)M_xO_2 (M=Fe,Co). In Ti_(0.8)Co_(0.2)O_2 and Ti_(0.6)Fe_(0.4)O_2 nanosheets, a strong magneto-optical response (～10~4 deg/cm) appeared near the absorption edge at 260 nm. We find that tailoring magneto-optical properties could be achieved by (Fe/Co) cosubstitution and an optimally doped Ti_(0.75)Fe_(0.1) [Co_(0.15)O_2 nanosheet exhibits a gigantic magneto-optical response (～10~5 deg/cm) over the wide wavelength region (400-750 nm). By analyzing electronic structures from first-principle calculations, we have clarified that the d-d transitions are responsible for the gigantic signal in (Fe/Co)-cosubstituted nanosheets.