Ab initio study of the electronic and magnetic structure of the TiO2 rutile (110)/Fe interface
A. Grünebohm, P. Entel, H. C. Herper.
Physical Review B, 88, 155401, (2013)
Adsorption of Fe on the rutile (110) surface is investigated by means of ab initio density functional theory calculations. We discuss the deposition of single Fe atoms and increasing Fe coverage, as well as the adsorption of small Fe clusters. It is shown that the different interface structures found in experiment can be understood in terms of the adsorption of the Fe atoms landing first on the rutile surface. Strong interface bonds form if single Fe atoms are deposited. The Fe-Fe bonds in deposited Fe clusters lead to a three-dimensional growth mode. Mainly ionic Fe oxide bonds are formed in both cases and the electronic band gap of the surface is reduced due to interface states. In addition to the structural and electronic properties, we discuss the influence of the interface on the magnetic properties, finding stable Fe moments and induced moments within the interface which lead to a large spin polarization of the Fe atoms at the rutile (110)/Fe interface.