Mössbauer study of nano-TiO2 doped with Fe

Abstract

A Mossbauer study of nano-TiO2 doped with Fe is presented. The samples are prepared by sol-gel method, doping Fe by 5, 10 and 15 wt.%, respectively, which are measured with XRD, TEM and Raman spectra. Especially, Mossbauer spectra are emphasized in this study. The anatase phase is major in both doped and no-doped sample. The α-Fe2O3 phase is also in the doped samples. The grain size of doped sample is in 5–20 nm range, the major grains are about 13 nm. And the grain size of no-doped sample is about 8 nm. Studying Mossbauer spectra and Raman spectra, we concluded that in the doping process the Fe3+ ions entered anatase lattice and substituted Ti4+ ions. However, the amount of Fe ions in the site is limited to about 1.5 wt.%. It does not increase as the doping Fe increase. The more Fe doped, the more α-Fe2O3 formed. For comparing conveniently, it also can be described as (Ti0.98Fe0.02) O2 by atomic percent.