Black chromium coatings : experimental and calculated optical properties using inhomogeneous medium theories
نویسندگان
چکیده
2014 Bulk composition, surface and volume structures and optical characterization of selective black chromium coatings used for photothermal conversion of solar energy are presented. A model of the optical properties, taking into account all these parameters and using Maxwell Garnett and Effective Medium Theories for the determination of an effective dielectric constant for the inhomogeneous and rough media, is then developed. The influence of different roughness profiles is considered. The optical behaviour obtained with the different theories is examined and the limitations of these theories are discussed. LE JOURNAL DE PHYSIQUE TOME 40, NOVEMBRE 1979, Classification Physics Abstracts 78.65 88.60
منابع مشابه
Development of spacecraft black thermal control coatings using the synthesized mesoporous Co3O4 pigment
The thermo-optical properties of coated surface are important for spacecraft thermal control coatings which depend on the optical properties and structure of the coating material. These coatings control the temperature by their capability of outer energy absorption and its emission. The optical properties of pigment can be improved if the pigment contains a high fraction of voids in its structu...
متن کاملPlasma spraying and characterization of chromium carbide – nickel chromium coatings
Chromium carbide – nickel chromium powder Cr3C2-25wt.NiCr was plasma sprayed by a water-stabilized system WSP®. A series of experiments with variable feeding distance was carried out. Basic characterization of coatings was done by XRD, SEM and light microscopy plus image analysis. Microhardness was measured on polished cross sections. The main focus of investigation was on resistances against w...
متن کاملEFFECT OF MULTI-STEP ANODIZING METHODS ON THE OPTICAL ABSORPTION OF BLACK COATINGS ON 2024 ALUMINUM ALLOY
Development of materials with the ideal black body absorption spectrum are of great interest. Such materials could improve the efficiency of solar cells, and passive cooling and heat transfer systems as well as the protective and decorative coatings. Fabricating black anodizing coatings is promising for this purpose because they exhibit low light reflection from the surface. Such coatings can ...
متن کاملAngular selective window coatings: theory and experiments
This review is devoted to the angular selectivity that can be obtained in thin films prepared under conditions such that they contain inclined absorbing regions of sizes much smaller than the wavelength of visible light. The films are of considerable interest as window coatings for energy-conscious architecture and, potentially, in the automotive sector. The theoretical basis for modelling the ...
متن کاملOmnidirectional, broadband light absorption using large-area, ultrathin lossy metallic film coatings
Resonant absorbers based on nanostructured materials are promising for variety of applications including optical filters, thermophotovoltaics, thermal emitters, and hot-electron collection. One of the significant challenges for such micro/nanoscale featured medium or surface, however, is costly lithographic processes for structural patterning which restricted from industrial production of compl...
متن کامل