Combustion synthesis and properties of fine particle fluorescent aluminous oxides

Abstract

Fine particle fluorescent aluminous oxide materials like Cr3+-doped α-Al2O3 (ruby), MgAl2O4, LaAlO3, Y3Al5O12 and Ce3+-doped Y3Al5O12, LaMgAl11O19, CaAl12O19 and CeMgAl11O19 have been prepared by the combustion of the corresponding metal nitrate-aluminium nitrate-urea/carbohydrazide mixtures at 500°C in less than 5 min. Formation of these Cr3+- and Ce3+-doped aluminous oxides has been confirmed by their characteristic XRD, colour, UV-visible and fluorescence spectra as well as decay time measurements. Ruby (Cr3+/α-Al2O3) powder showed characteristic excitation bands at 406 and 548 nm and emission band at 695 nm with the decay time of 3·6 ms.