These results suggest that there are some oxygen vacancies in the nanofibers, and that these oxygen vacancies are the maincause of the induction of room temperature ferromagnetism in La0.5Sr0.5Ti1−xNixO3 nanofibers.23,27–29) The higher-binding energy peaks centered at ∼532.4 eV (OIII) and 533.5 eV (OIV) are associated with the presence of loosely bound
oxygen on the surface of La0.5Sr0.5TiO3 nanofibers such as –NO3, –CO3, and adsorbed H2O.