Ultraviolet-infrared optical properties of highly (100)-oriented LaNiO₃ thin films on Pt-Ti-SiO₂-Si wafer

The optical constants of highly (100)-oriented LaNiO₃ thin films on Pt(111)-Ti-SiO₂-Si substrate derived by metalorganic deposition have been obtained using spectroscopic ellipsometry techniques in the wide wavelength range from ultraviolet to far infrared. In fitting the dielectric functions of LaNiO₃, two harmonic oscillators are observed, one is believed to come from the valence-conduction interband transition and the other is attributed to the transition from a donor band to the conduction. Simultaneously the frequency of plasmon is also obtained, which results from the strong electron-electron interaction. Based on these optical and electrical properties, a promising application of LaNiO₃ thin films in infrared microsensors has been proposed.