Cava, SergioBeninca, RenataTebcherani, Sergio M.Souza, Iedo A.Paskocimas, Carlos A.Longo, Elson [UNESP]Varela, José Arana [UNESP]2014-05-202014-05-202007-07-01Journal of Sol-gel Science and Technology. Dordrecht: Springer, v. 43, n. 1, p. 131-136, 2007.0928-0707http://hdl.handle.net/11449/25446Al2O3 and Al2-x Cr (x) O-3 (x = 0.01, 0.02 and 0.04) powders have been synthesized by the polymeric precursors method. A study of the structural evolution of crystalline phases corresponding to the obtained powders was accomplished through X-Ray Diffraction and UV-vis spectroscopy (reflectance spectra and CIEL* a*b* color data). The obtained results allow to identify the gamma-Al2O3 to alpha-Al2O3 phase transition. The single-phase alpha-Al2O3 powder was obtained after heat treatment at 1050 degrees C for 2 h. The results show that the green to red color transition and ruby luminescence lines observed for the powders of Al2-x Cr (x) O-3 are related to the gamma to alpha-Al2O3 phase transition and the temperature and time range for such transition depends on the chromium content.131-136engAl2O3Al2-xCrxO3phase transitionpowder synthesisspectroscopypolymeric precursor methodArtigo10.1007/s10971-007-1541-yWOS:000247194300019Acesso restrito