Structure and electronic properties of Fe-Ti thin films

Fe/Ti multilayers (MLs) prepared onto glass substrates using UHV RF/DC magnetron sputtering. Results showed a significant drop of the coercivity measured for the Fe/Ti MLs with decrease in Fe layer thickness - typically from Hc ~ 2.2 kA/m to Hc ~ 0.2 kA/m - observed at a critical Fe thickness dcrit ~ 2.3 nm. Structural studies showed that the deposition of the 0.18 nm - Fe / 0.22 nm - Ti ML at 285 K leads to the formation of an uniform amorphous Fe-Ti alloy thin film due to a strong interdiffusion during the growth process. On the other hand, in-situ annealing of this ML at 750 K for 2 h resulted in the creation of a nanocrystalline phase. Furthermore, in-situ XPS studies showed that the valence band of the nanocrystalline Fe-Ti alloy film is broader compared to that measured for the amorphous phase with the same average composition.