Optical and structural properties of LaF3 thin films

LaF3 thin films of different thicknesses were deposited on CaF2 (111) and silicon substrates at a relatively low substrate temperature of 150 °C. Optical (transmittance, reflectance, refractive index, and extinction coefficient) and mechanical (morphology and crystalline structure) properties have been investigated and are discussed. It is shown that LaF3 thin films deposited on CaF2 (111) substrates are monocrystalline and have a bulklike dense structure. Furthermore, it is presented that low-loss LaF3 thin films can be deposited not only by boat evaporation but also by electron beam evaporation.