Magnetic and optical properties of WO3/TiO2 superlattice

• We found the magnetic phenomenon in the WO3/TiO2 thin film.
• The electrons transfer from TiO2 and WO3 induce the occurrence of ferromagnetism.
• The electrons transfer between TiO2 and WO3 shift the absorption region to visible light.

The electronic structure and properties of WO3/TiO2 superlattice were investigated by the calculation and experiment. The O electrons transfer the spin angular momentum from the unoccupied Ti eg states electrons to W eg states electrons and let Ti and W electrons spin splitting, which were the reason of ferromagnetism occurrence, while the electrons transfer from the CB of TiO2 to the CB of WO3. Coupling TiO2 and WO3 greatly reduce the recombination rate of electron and hole and shift the absorption region to visible light because of the electrons transfer between TiO2 and WO3.