| Autor: |
KalužA, Leon, Šurca-Vuk, Angela, Orel, Boris, Dražič, Goran, Pelicon, Primož |
| Zdroj: |
Journal of Sol-Gel Science & Technology; Jan2001, Vol. 20 Issue 1, p61-83, 23p |
| Abstrakt: |
Black colored CuFeMnO4 spinel powders and films were prepared using sol-gel process from Mn-acetate and Fe- and Cu-chloride precursors. Films were deposited by dip-coating technique and heat-treated at 500°C. For CuFeMnO4/silica films 3-aminopropyl-triethoxysilane (3-APTES) or tetraethoxysilane (TEOS) were used in molar proportion (Mn : Cu : Fe) : silica = 1 : 1. Films and powders were prepared by heating at 500°C. IR spectroscopic measurements were employed to follow the hydrolysis-condensation reactions in (Mn : Cu : Fe)/3-APTES sols hydrolysed with water, and (Mn : Cu : Fe)/TEOS sols hydrolysed with (NH3)aq (Stöber processing). The resulting coatings were examined with transmission electron microscopy (TEM) combined with electron dif-fraction analyses, Rutherford back scattering (RBS) and proton induced X-ray emission (PIXE) techniques. Results revealed that (Mn : Cu : Fe)/3-APTES films had a composite structure consisting of the upper Cu1.4Mn1.6O4 spinel and the lower amorphous SiO2 layer. RBS measurements confirmed the composite structure, showing also that the composition of the film was Mn : Cu : Fe = 1 : 0.96 : 0.29, i.e. close to the precursors ratio Mn : Cu : Fe = 3 : 3 : 1. (Mn : Cu : Fe)/TEOS films prepared from sols which were catalysed with (NH3)aq consisted of amorphous monodispersed spherical SiO2 particles with a size of about 400–420 nm. Solar absorbance ( as) and thermal emittance ( eT) values of CuFeMnO4 (500°C) and (Mn : Cu : Fe)/TEOS films (500°C) showed that CuFeMnO4 films could be used as potential selective coatings for solar absorbers in solar collector systems. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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