Dissertation > Industrial Technology > Chemical Industry > Silicate > Ceramic Industry > Production process and equipment

Preparation and Spectroscopic Properties of Er3+:Lu2O3Nano-powders and Transparent Ceramics

Author WangPengHe
Tutor WangNengLi
School Changchun University of Science and Technology
Course Materials Science
Keywords lutetium(Ⅲ) oxide nanopowders co-precipitation solid state reaction Transparent ceramic Photoluminescent
CLC TQ174.6
Type Master's thesis
Year 2012
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Er-doped lutetium(III) oxide (Er3+:Lu2O3), with excellent physical and optical properties, has emerged as a promising candidate for ceramic scintillators and the laser gain medium used in the short-pulsed laser and high-power laser, and can be used widely in various area, such as infrared quantum counter detectors, biological medicine, optical data storage, environmental monitoring and so on. In this paper, the synthesis of Er3+:Lu2O3powders were investigated by a co-precipitation processing and the solid state reaction method, and the transparent Er3+:Lu2O3ceramics were fabricated by using the synthesized powers. Then photoluminescence properties of the powers and ceramics are also discussed. The main points are as follows:Er3+:Lu2O3nanopowders with excellent properties were prepared by co-precipitation processing,The effects of precipitants, dispersants and process parameters of co-precipitation processing and temperature of calcining of the precursor were discussed. The results indicate that powders were synthesized by co-precipitation process with NH4HCO3as precipitant and (NH4)2SO4and PAM as dispersants, respectively, exhibited homogeneously spherical morphology and good dispersivity when calcined at1000℃for2h, and the particle size are about50-60nm. The Er3+:Lu2O3nanopowders synthesized with tartaric acid as precipitant have bigger particle size of about75nm and relatively lower sintering activity. By studing the densification behavior and the grain growth behavior of Er3+:Lu2O3ceramics compacts during the sintering process, it is found that both the sintering mechanism and the grain growth of ceramic were dominated by grain boundary diffusion. The Er3+:Lu2O3transparent ceramics were prepared by vacuum sintering at1650℃for8~12hours and the transmittance can reached55.4%High optical quality Er3+:Lu2O3transparent ceramics were fabricated with home commercial powders by the solid state reaction processing,the transmittance can reached63.8%at a wavelength range of400-800nm.The sintering aid (TEOS:0.5wt.%) can effectively suppressed the grain-boundary migration,and improve density and transmittance of Er3+:Lu2O3transparent ceramics.Excessive La2O3over5at.%will increase the distortion of the grain ceramic structure. At high temperatures,the La2O3reacted with Lu2O3to form the second phase LaLuO3, thus affecting the optical properties of transparent ceramics.Finally, the spectroscopic properties of Er3+:Lu2O3powders and bulks were investigated. The red and green up-conversion luminescence of Er3+:Lu2O3nanocrystalline and bulks samples under the excitation of a980nm continuous wave diode laser (LD) was be observed in the visible region of the spectrum. The intensity of up-conversion emission revealed an enhancement of the red4F9/2→4I15/2mission with respect to the green2H11/2,4S3/2→4I15/2emission when the dopant concentration is increased. It is explained by the cross relaxation processing of (2H11/2,4S3/2)+4F9/2→4I15/2+4I13/2. The effects of the morphology of nanopowders on the up-conversion luminescence properties are also discussed. In addition, the NIR luminescence of Er3+:Lu2O3ceramics at wavelength of1553nm, with different Er3+concentrations, upon excitation of980nm were discussed, the results show that the most intensity NIR luminescence of the bulks can be observed when the dopant concentration of Er3+is between2.0and3.0at.%, and the intensity of NIR luminescence become weak when the concentration of Er3+ions is higher than3at.%.

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