Growth and properties of molecular beam epitaxially grown ferromagnetic Fe-doped TiO2 rutile films on TiO2(110)

We have grown epitaxial Fe-doped ${\mathrm{TiO}}_2$ rutile films on rutile ${\mathrm{TiO}}_2\text{(110)}$ substrates, and have explored the resulting compositional, structural, morphological and magnetic properties. Clusters of mixed ${\mathrm{TiO}}_2$ rutile and ${\mathrm{Fe}}_3{\mathrm{O}}_4$ form on the surface of a continuous rutile epitaxial film during growth. Room-temperature ferromagnetism is observed, and is associated with the formation of secondary phase ${\mathrm{Fe}}_3{\mathrm{O}}_4$ rather than a true diluted magnetic oxide semiconductor.