Oxidation Induced Aging Of Spectrally Selective Coatings Obtained By D.C. Magnetron Sputtering Of Cu and Cr

Abstract

Aging (under heating in air at 100 °C ) of Cu and Cu -Cr coatings on glass substrates has been studied by measuring the spectral transmittance and reflectance in the wavelength range 0,4 -25pm. The results show a fast oxidation of copper films.In the case of CuCr double layer system an initial increase of the IR reflectance has been observed.After this stage the system shows a selectivity similar to that of a single as-received Cu films and very good stability to the oxidation. The prolonged heating (up to 600 h) in air at 100 °C does not essentially change the IR reflectance of the Cu -Cr system.The increase of the IR reflectance of Cu -Cr coatings in the initial stage of heating and their further stability has been explained, supposing an oxidation of the Cr layer.