Optical, Magnetic, and Electronic Properties of Nanostructured VO2 Thin Films Grown by Spray Pyrolysis: DFT First Principle Study

Abstract

In this work, we have grown nanostructured vanadium dioxide (VO2) thin films by a spray pyrolysis coating method on glass pre-heated substrates at 450 °C and studied their optical and electronic properties. As-prepared film structure and morphology, with a thickness of ~ 400 nm, were examined by X-ray diffraction, Raman spectra, and atomic force microscopy (AFM), thus revealing a polycrystalline monoclinic M1 phase. On the other hand, the electrical resistance was measured as a function of the temperature in the range of 25 to 100 °C where a clear transition from the M1 phase at T = 25 °C to the metallic one (conductive phase) at ~ 60 °C was observed. This also confirms the stability of the M1 phase for T < 60 °C. The electronic properties and band structure were additionally investigated by the local density approximation (LDA) using the first principle of the Korringa-Kohn-Rostroker (KKR). As a result, our material showed a magnetic property, specifically an antiferromagnetic stabilization of the M1 phase.