Infrared spectroscopic study of sol–gel derived mixed-metal oxides

• Published in: Journal of non-crystalline solids Vol. 279; no. 2; pp. 119 - 125
• Main Authors: Parler, Caroline M., Ritter, James A., Amiridis, Michael D.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 2001; Elsevier
• Subjects: Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Lattice dynamics; Materials science; Materials synthesis; materials processing; Phonon states and bands, normal modes, and phonon dispersion; Phonons and vibrations in crystal lattices; Physics; Sol-gel processing, precipitation; S310; I160; Inorganic compounds; Silicon oxides; Transition element compounds; Vibrational modes; Chemical bonds; Binary compounds; Fourier transform spectra; Metals Oxides; Infrared spectra; Experimental study; Fabrication property relation; Sol-gel process
• ISSN: 0022-3093; 1873-4812
• DOI: 10.1016/S0022-3093(00)00401-4

Binary, mixed-metal oxides of silicon–aluminum, silicon–cobalt, silicon–copper, silicon–iron, and silicon–nickel were produced via a sol–gel method and characterized with in situ Fourier transform infrared (FTIR) spectroscopy over the temperature range from 30°C to 350°C. Characteristic Si–O–Si IR stretches, observed at 1086 and 798 cm −1 , shifted to lower frequencies as the second metal oxide was introduced to the system, suggesting a weakening of the Si–O–Si network. In addition, new peaks observed in the 600–700 cm −1 range were assigned to silicon–oxygen–metal vibrations providing further evidence that the second metal was chemically incorporated into the gel network. Heating these mixed-metal oxides to 350°C only dehydroxylated the surface, with no other structural changes observed. This result indicated that the mixed-metal oxide structure, including silicon–oxygen–metal bonds, was formed during the synthesis and drying stages at relatively low temperatures (i.e., 90–110°C).