Phase transitions in thin titanium oxide films under the action of excimer laser radiation

We have studied the action of pulsed vacuum ultraviolet (VUV) radiation of an ArF excimer laser (wavelength, 193 nm; pulse duration, 20 ns; pulse energy density, 40–50 J/cm2) on thin amorphous films of titanium oxide (TiO2) grown by light-assisted molecular beam epitaxy. A comparison of the Raman spectra of samples measured before and after exposure shows that VUV irradiation at increasing fluence induces the crystallization of amorphous TiO2 to anatase, which is further transformed into rutile.