Preparation and Luminescent Properties of Cr~(3+):Al_2O_3 Powders by Precipition Method

NH4MO(OH)HCO3(M=Al3+, Cr3+) precursors were synthesized by a co-precipition method with the solutions of mixed nitrates as starting materials and ammonium bicarbonate as precipitator. The precursors and powders sintered at various temperatures were characterized by thermogravimetry/differential thermal analysis(TG/DTA), infrared spectroscopy(IR), X-ray diffractormetry(XRD), transmittion electron microscopy(TEM). The luminescent spectra of Cr3+∶Al2O3 nano-powder was measured. The XRD results show that the pure-α-Al2O3 phase can be obtained at 1 200 ℃. TEM analysis indicates that the nano-powders about 20~30 nm are well-dispersed and less-aggregated. Spectral analysis demonstrates that the sample has good photoluminescence.