Investigation of structural, optical and micro-mechanical properties of (NdyTi1 − y)Ox thin films deposited by magnetron sputtering

• Thin film coatings were prepared by magnetron sputtering in pure oxygen plasma.
• Increase of the neodymium concentration caused amorphisation of prepared coatings.
• Doping TiO2 with Nd decreased the refractive index and extinction coefficient.
• Neodymium addition in the amount of 4, 7 and 10 at.% caused hardening of the coating.
• The highest hardness was obtained for (Nd0.07Ti0.93)Ox thin films.

TiO2 and (NdyTi1 − y)Ox thin films were deposited by reactive magnetron sputtering process from mosaic Ti–Nd targets and characterised by X-ray diffraction (XRD), Raman optical spectroscopy and nanoindentation technique. XRD measurements revealed that as-prepared titanium dioxide and TiO2 thin films with 4 and 7 at.% of Nd had nanocrystalline rutile structure, while coatings with larger amount of Nd were amorphous. Raman spectroscopy investigations showed that the increase of the neodymium concentration caused amorphisation of the coatings and hindered their crystal growth. All as-prepared coatings were transparent in the visible wavelength range with a transmittance of approximately 80%. The refractive index and extinction coefficient of the thin films gradually decreased with the increase of the neodymium concentration. Micro-mechanical properties, i.e. hardness and elastic modulus, were determined using traditional load-controlled nanoindentation testing and continuous stiffness measurements. The highest hardness and elastic modulus values were obtained for thin films with 7 at.% of Nd and were approximately 14.8 GPa and 166.3 GPa, respectively.

Figure optionsDownload as PowerPoint slide