Abstract
The structural, optical and magnetic behavior of undoped TiO2 nanoparticles synthesized by sol-gel technique annealed at 400 °C in air for different time periods were studied. Tetragonal anatase phase was formed in all the samples as studied from X-ray diffraction, and Raman spectroscopy. HRTEM showed the particles in the nanometer range (13–16 nm) Photoluminescence and XPS show the formation of oxygen vacancies and Ti3+ions. Clear hysteresis is observed at low field, but there is a lack of saturation magnetization, suggesting the presence of paramagnetic/diamagnetic contributions. The bound magnetic polaron (BMP) is proposed to be the mechanism of ferromagnetism (FM) which is formed by overlapping of orbital of trapped electrons in F+ center with the unpaired (3d1) electron of Ti3+ions. The increase of magnetic moment with the increase in annealing time can be due to a greater number of BMPs participating in FM exchange and the same have formed due to the formation of large number of oxygen vacancies and Ti3+ ions in TiO2 nanocrystals.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
