Intermetallic charge transfer and band gap of MTiO3 (MÂ =Â Mn, Fe, Co, and Ni) studied by O 1s-edge X-ray emission spectroscopy

Charge transfer is a key concept in understanding X-ray spectra of transition metal oxides. In this study, X-ray absorption spectra (XAS) and X-ray emission spectra (XES) at the O 1s-edge of MTiO3 (ilmenite: M = Mn, Fe, Co, and Ni) have been measured. It was found that the O 1s-edge XES show the existence of not only oxygen-metal charge transfer but also intermetallic charger transfer. Moreover, the band gap of each ilmenite was evaluated to be 2.4-2.8 eV by measuring the distance between the spectra edges of XAS and XES.

► X-ray absorption spectra and X-ray emission spectra at the O 1s-edge of MTiO3 (ilmenite: M = Mn, Fe, Co, and Ni) have been measured. ► It was found that the O 1s-edge XES show the existence of not only oxygen-metal charge transfer but also intermetallic charger transfer. ► The band gap of each ilmenite was evaluated to be 2.4-2.8 eV by measuring the distance between the spectra edges of XAS and XES.