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Synthesis of luminescent KY_3F_(10) nanopowder multi-doped with lanthanide ions by a co-precipitation method

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Journal of Rare Earths 2016年第8期34卷 808-813页

作者： Szymon Goderski Marcin Runowski Stefan Lis Department of Rare Earths Faculty of Chemistry Adam Mickiewicz University

A series of KY3F10 nanophosphors doped with Gd3＋, Ce3＋ and Eu3＋ ions were obtained with the use of a co-precipitation method. The resulting products were white precipitates, consisting of spherical particles with diameter about 150-200 nm, which was confirmed using transmission electron microscopy （TEM） technique. Powder X-ray diffraction （XRD） and energy dispersive X-ray analysis （EDX） measurements confirmed appropriate structures of the nanoparticles obtained. Spectroscopic properties of the prod- ucts were examined on the basis of the measured excitation/emission spectra and luminescence decay curves. The synthesized sam- ples showed orange-red luminescence, characteristic for Eu3＋ ions. The reaction process was performed in required alkaline pH ad- justed with the use of ethylenediaminetetraacetic acid （EDTA） and potassium hydroxide. The samples containing large amounts of Gd3＋ dooant ions exhibited a tendencv to form nroducts with different momhologies.

关键词： : fluorides co-precipitation nanophosphors luminescence nanopowders Ce3+/Gd3+/Eu3+ doping rare earths

Synthesis of Yb:Lu_3Al_5O_(12) nano powders with the reverse strike co-precipitation method:influence of decomposition of NH_4Hco_3

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Journal of Rare Earths 2016年第9期34卷 901-907页

作者：陈思圆范金太潘良杰姜本学毛小建李日红袁新强姜雄伟张龙 Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences School of Materials Science and Engineering Shanghai University

Yb：Lu3Al5O12 （Yb：LuAG） nano powders were synthesized with the co-precipitation method from cation （Lu3＋, Yb3＋, Al3＋） solution of different concentrations using NH4Hco3 as the precipitant. The influence of cation concentration on the morphology and purity of the calcined powders was studied. contrary to the conventional suggestion that recommends thin solution to obtain loosely agglomerated nano powders, results showed that thin cation （Lu＋Yb＋Al） concentration ≤0.08 mol/L led to formation of Al2O3 and LuAP impurities in the obtained nano powders. By means of Tg/（DTA）, X-ray diffraction （XRD）, scanning electron microscopy （SEM）, the cause was revealed to be re-dissolution of Lu at high pH value that resulted from the decomposition of NH4Hco3.（Lu＋Yb＋Al） concentration of ~0.24 mol/L was recommended to achieve pure Yb：LuAG nano powders. Transparent Yb：LuAG ceramics were fabricated with the prepared Yb：LuAG nano powders. The transmittance around 800 nm was 77.5%.

关键词： Yb:LuAG transparent ceramics co-precipitation rare earths

ITO nano-powders prepared by microwave-assisted co-precipitation in aqueous phase

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中国有色金属学会会刊：英文版 2009年第S3期19卷 752-756页

作者：朱协彬姜涛邱冠周黄伯云 School of Minerals Processing and Bioengineering Central South University

By using microwave-assisted co-precipitation in aqueous phase, adding surface activation agent PEG-6000 into the mixture of InCl3 solution and SnCl4 solution, and dropping the ammonia solution with the density (volume ratio) of 1-0 to 1-4, ITO precursor was prepared at different reaction system temperatures of 35 ℃-85 ℃, then ITO nano-powder was obtained after it was calcinated at 800 ℃ for 1 h. The morphology of ITO nano-powder was characterized by SEM and its electrical conductivity was determined by conductivity meter. The effects of different temperatures and ammonia concentration in microwave-assisted reaction system on its morphology and electric conductivity were discussed. The experimental results indicate that with the dilution of the ammonia solution or the rise of reacting system temperature, the morphology of ITO particles is transformed from spherical to rod-like one with the decline of its electric conductivity. And the electric conductivity of ITO nano-powders with spherical morphology is higher than that of ITO nano-powders with rod-like morphology.

关键词： ITO nano-powder surface activation agent PEG-6000 microwave assistance co-precipitation aqueous phase

Solution-Phase Synthesis and Characterization of Perovskite LacoO_3 Nanocrystals via A co-precipitation Route

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Journal of Rare Earths 2007年第5期25卷 601-604页

作者：朱俊武孙小杰王艳萍汪信杨绪杰陆路德 Materials Chemistry Laboratory Nanjing University of Science and Technology

A facile co-precipitation route for the synthesis of well-dispersed LacoO3 nanocrystals was developed. The asprepared products were characterized by X-ray diffraction （XRD）, transmission electron microscopy （TEM）, energy dispersive X-ray spectrometer （EDX）, and laser Raman spectroscopy （LRS）. The resuks showed that modulating the growth parameters, such as the addition of surfactants as well as the adding manner of the precipitator had a significant effect on the overall shape and size of the obtained nanocrystals. The nanorods with the diameter of 20 nm and spherical LacoO3 nanocrystals with the size of about 25 nm could be obtained at a relatively low calcining temperature of 600℃. Furthermore, the Raman properties of LacoO3 products obtained at different calcining temperatures were investigated.

关键词： perovskite LacoO3 co-precipitation nanocrystals rare earths

Synthesis and properties of strontium hexa-ferrite ultrafine powders via a CTAB-assisted co-precipitation method

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Rare Metals 2017年第8期36卷 666-670页

作者： Jun-Liang Liu Xiu-Lie Chen Sheng-Yun Wang Lei-Ming Yan Ming Zhang School of Chemistry and Chemical Engineering Yangzhou UniversityYangzhou 225002China

Single-phase SrM ultrafine powders with single-domain particle ranging from 200 to 400 nm in size were successfully synthesized by a cetyltrimethylammonium bromide（CTAB）-as sis ted co-precipitation method,and excellent magnetic properties with saturation magnetization of 68.6 A·m^2·kg^（-1） and coercive field of 0.5250 T are *** CTAB content exceeds 5.0 wt%,the impurities emerge due to the deterioration of simultaneous precipitations of the starting materials and the deviation of Sr/Fe molar ratio from stoichiometry ratio in the local microdomains by employing CTAB in co-precipitation ***,the use of CTAB can effectively improve the homogeneities of Fe-precursor particles with Sr-precursor particles,exert surface barriers to inhibit interdiffusion,and constrain the crystal growth in the local microdomains during sintering,resulting in smaller particle sizes and more uniform particle size distribution.

关键词： Strontium hexa-ferrite Nanopowders co-precipitation Surfactants Magnetic properties

Characterization of ZnS nanoparticles synthesized by co-precipitation method

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Chinese Physics B 2015年第4期24卷 306-309页

作者： Parvaneh Iranmanesh Samira Saeednia Mohsen Nourzpoor Department of Physics Vali-e-Asr University of Rafsanjan Department of Chemistry Vali-e-Asr University of Rafsanjan

ZnS nanoparticles are prepared by homogeneous chemical co-precipitation method using EDTA as a stabilizer and capping agent. The structural, morphological, and optical properties of as-synthesized nanoparticles are investigated using x-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, ultraviolet-visible （UV-Vis） absorption, and photoluminescence spectroscopy. The x-ray diffraction pattern exhibits a zinc-blended crystal structure at room temperature. The average particle size of the nanoparticles from the scanning electron microscopy image is about 50 nm. The ultraviolet absorption spectrum shows the blue shift in the band gap due to the quantum confinement effect. The photoluminescence spectrum of ZnS nanoparticles shows a blue visible spectrum.

关键词： nanoparticles zinc sulfide optical properties co-precipitation

Structural & Magnetic Characterizations of NiLiZn Nanoferrites Synthesized by co-precipitation Method

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Journal of Materials Science & Technology 2011年第11期27卷 991-995页

作者： D.N. Rohadiana Z.A.Z. Jamal S.B. Jamaludin M.F. Bari J. Adnan Sustainable Engineering Research Cluster Universiti Malaysia Perlis School of Microelectronic Engineering Universiti Malaysia Perlis

Synthesis of ***（0.5-x）Fe204 nanoparticles with x=0, 0.1, 0.2, 0.3, 0.4 and 0.5 were realized via coprecipitation method. X-ray diffraction （XRD） and vibrating sample magnetometer （VSM） measurements were performed on the samples to determine the characteristics of the crystal structures and the magnetic properties of the samples, respectively. The spinel phase structures of the samples were confirmed by XRD analysis. Patterns of decreased lattice parameter and increased crystallite size values were observed by increasing the Li concentration at longer synthesis reaction periods. Similarly, for the magnetic properties, both the saturation magnetization （Ms） and coercivity （Hc） were found to vary with increasing patterns at higher Li doping levels and longer synthesis reaction periods. The results and mechanisms concerned were discussed.

关键词： Lithium nickel zinc ferrite co-precipitation Crystal structure Magnetic properties

Preparation and Characterization of Gd_3Sc_2Ga_3O_(12) Polycrystalline Material by co-precipitation Method

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Journal of Rare Earths 2007年第2期25卷 158-162页

作者：邵淑芳张庆礼苏静孙敦陆王召兵殷绍唐 Anhui Institute of Optics and Fine Mechanics Chinese Academy of Sciences

Gd3Sc2Ga3O12 polycrystalline material for single crystal growth was prepared with Ga, Gd2O3 and Sc2O3 as starting materials and aqueous ammonia as the precipitator by co-precipitation method. The precursors sintered at various temperatures were characterized by infrared spectra （IR）, X-ray diffractometry （XRD） and transmitted electron microscopy （TEM）. The results showed that pure GSGG phase could be obtained at 900 ℃. The sintered powders were well-dispersed and less-aggregated in the sintered temperature range of 900 - 1000 ℃. XRD and TEM show that the polycrystalline particle sizes of the polycrystalline powders were about 20 - 50 nm. compared with the method that Ga2O3, Gd2O3 and Sc2O3 were mixed directly and sintered to get polycrystalline materials, the synthesized temperature was lower and sintered time was shorter. Thus co-precipitation was a good method to synthesize GSGG polycrystalline material.

关键词： Gd3Sc2Ga3O12 co-precipitation laser crystal rare earths

Spectroscopic properties of Eu^(3+) doped YBO_3 nanophosphors synthesized by modified co-precipitation method

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Journal of Rare Earths 2011年第12期29卷 1142-1146页

作者： A.Szczeszak S.Lis V.Nagirnyi Department of Rare Earths Faculty of ChemistryAdam Mickiewicz University Institute of Physics University of Tartu

Y1-xEuxBO3 nanophosphors were synthesized by a modified co-precipitation method. The structure of the obtained nanocrystals was determined by X-ray diffraction （XRD） and transmission electron microscopy （TEM）. The average crystallite size was calculated from the full-width at half-maximum （FWHM） of the diffraction peaks by the Scherrer equation. The average particles size was 25±10 nm. The spectroscopic properties of the Y1-xEuxBO3 nanoborates were characterized by excitation and emission spectra under UV and VUV excitation. In order to improve colour purity, the chromaticity coordinates were also calculated.

关键词： YBO3:Eu^3+ co-precipitation nanophosphor luminescence VUV rare earths