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Homoepitaxial thin films of Fe:TiO 2 and (Fe,N):TiO 2 were deposited on rutile(110) by molecular beam epitaxy. X-ray absorption near edge spectroscopy (XANES) spectra were collected at the Ti L-edge, Fe L-edge, Ti K-edge, O K-edge, and N K-edge. No evidence of structural disorder associated with a high concentration of oxygen vacancies is observed. Substitution of Fe for Ti could be inferred, and secondary phases such as Fe 2 O 3 , Fe 3 O 4 , and FeTiO 3 can be ruled out. The similarity of the N K-edge spectra to O, and the presence of a strong x-ray linear dichroism signal for the N K-edge, indicates that N is substitutional for O in the rutile lattice and is not present as a secondary phase such as TiN. Simulations of the XANES spectra confirm substitution, although N appears to be present in more than one local environment. Neither Fe:TiO 2 nor (Fe,N):TiO 2 exhibit intrinsic room temperature ferromagnetism, despite the presence of mixed valent Fe(II)/Fe(III) in the reduced (Fe,N):TiO 2 film.

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