Lanthanum oxyfluoride sol-gel thin films by a simple single-source precursor route

Highly transparent and homogeneous nanostructured LaO1-xF1+2x (0 <= x <= 1) thin films have been synthesized by 0 a simple sol-gel procedure using La(hfa)(3)center dot diglyme (Hhfa = 1,1,1,5,5,5-hexafluoro-2,4-pentailedione; diglyme = bis(2-metoxyethyl) ether) as source compound for both lanthanum and fluorine. While thermal treatments up to 500 degrees C resulted in highly fluorinated nanosystems, i.e., LaF3 at 300 degrees C and LaF3 + LaOF at 500 degrees C, pure and single-phase nanostructured lanthanum oxyfluoride thin films with a mean crystallite size of similar to 15 nm have been obtained at 700 degrees C. The microstructure and composition of the samples and their interplay with the synthesis procedure were investigated by glancing incidence X-ray diffraction, X-ray photoelectron, and X-ray excited Auger electron spectroscopy. Finally, the optical properties of the films were studied by UV-vis-NIR spectroscopy and spectroscopic ellipsometry.