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

Abstract

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.