Preparation and optical characterization of e-beam deposited cerium oxide films

► Films of cerium oxide are prepared on quartz substrates at different temperatures, Ts. ► Films are transparent for a visible range and for NIR. ► For 300K⩽Ts⩽473K values of the refractive index n are between 1.91 and 2. ► For higher temperatures n increases strongly up to 2.34 at Ts=673K. ► These changes arise from structural changes (confirmed in the AFM, Raman spectroscopy and diffuse reflectance examinations). Cerium oxide films, of 0.3–1μm thickness, were reactively deposited in the oxygen atmosphere onto quartz plates by the PVD method. An electron gun was used as an evaporation source. Films were characterized with the AFM method, Raman spectroscopy and spectrophotometrically. Optical properties of these films were examined for the wavelength range 0.2–2.5μm. Films were characterized by high transparency, between 0.38 and 2.5μm. The complex refractive index, n*=n−jk, was evaluated. The dispersion characteristics for n(λ) and k(λ) were presented. We found that the refractive index strongly depends on the temperature of substrates (300K⩽Ts⩽673K) during film deposition. Estimated values of the refractive index (at λ=0.55μm) were in the range 1.91–2.34.