Investigating oxidation of niobium by laser treatment

Abstract

Composition, structure, and optical properties of films formed on the surface of niobium during laser processing are presented. Two modes of laser oxidation of niobium are empirically determined. The first mode, using single-pass laser processing, create the blue shade oxide film, the second mode, using multipass laser processing, forms the green shade oxide film. The optical contrast, determined as a difference of reflection coefficients, in the infrared spectrum of the blue oxide film is equal to 0.2 and the green oxide film forms the contrast equal to 0.5. It was found that the niobium blue shade oxide films, obtained after laser processing, has stoichiometry NbO and the green oxide film has stoichiometryNbO2.