稀土离子在CdSiO_3基质中的多光色长余辉发光

利用高温固相法合成了系列稀土离子掺杂的CdSiO_3:RE~(3+)(RE=Y,La,Ce,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho,Er,Tm,Yb,Lu)多光色长余辉磷光体。XRD分析结果表明在1050℃下烧结3小时的产物为单相。稀土掺杂CdSiO_3磷光体具有良好的发光性能。引入Y~(3+),La~(3+),Gd~(3+),Lu~(3+)以及Ce~(3+),Nd~(3+),Ho~(3+),Er~(3+),Tm~(3+),Yb~(3+)可获得一个最大发射中心位于420 nm附近的缺陷发光宽带,引入 Pr~(3+),Sm~(3+),Eu~(3+),Tb~(3+),Dy~(3+)时,除了产生约420 nm的蓝紫色缺陷发光外同时产生很强的稀土离子特征发光,这两种发光混合导致不同的余辉颜色。

Low temperature preparation of ceria solid solutions doubly doped with rare-earth and alkali-earth and their properties as solid oxide fuel cells

A series of solid electrolytes, (Ce(0.8)Ln(0.2))(1 - x)MxO2 - delta(Ln = La, Nd, Sm, Gd, M:Alkali-earth), were prepared by amorphous citrate gel method. XRD patterns indicate that a pure fluorite phase is formed at 800 degreesC. The electrical conductivity and the AC impedance spectra were measured. XPS spectra show that the oxygen vacancies increase owing to the MO doping, which results in the increase of the oxygen ionic transport number and conductivity. The performance of ceria-based solid electrolyte is improved. The effects of rare-earth and alkali-earth ions on the electricity were discussed. The open-circuit voltages and maximum power density of planar solid oxide fuel cell using (Ce0.8Sm0.2)(1 - 0.05)Ca0.05O2 - delta as electrolyte are 0.86 V and 33 mW . cm(-2), respectively.

Extraction mechanism of rare earths with sec-octylphenoxy acetic acid by two-phase titration technique

The compositions of the extracted complexes of La, Gd, Er and Y with sec-octyl-phenoxy acetic acid in heptane and the related apparent extraction equilibrium constants K-M were determined using two-phase titration technique. The stoichiometric compounds for La, Gd, Er and Y should be LaA(3) . 2.5HA, GdA(3) . 3HA, ErA(3) . 3.1HA and YA(3) . 4.3HA respectively. And their pK(M) are 3.43, 3.46, 3.08 and 2.58 respectively.

Synthesis and structural characterization of organolanthanide complexes with 1,2-dicarba-closo-dodecaborane-1,2-dichalcogenolate ligands

Reactions of anhydrous LnCl(3) (Ln = Nd, Gd, Dy, Er, Yb) with 2 equiv of LiCp' in THF afford the lanthanocene complexes Of CP'(2)Ln(mu-Cl)(2)Li(THF)(2) (CP' = eta(5)-t-BuC5H4, Ln = Nd (1), Gd (2), Dy (3), Er (4), Yb (5); Cp'= 1,3-eta(5)-t-Bu2C5H3, Ln = Nd (6), Gd (7), Dy (8), Er (9), Yb (10)). The molecular structures of 7 and 8 were characterized by X-ray crystallographic analysis. In these complexes, two Cp' ring centroids and two it-bridging chloride atoms around the lanthanide atoms form a distorted tetrahedron. The insertion of elemental chalcogen E (E = S, Se) into Li-C bonds of dilithium o-carborane in THF solution afforded dimers of dilithium. dichalcogenolate carboranes, [(THF)(3)LiE2C2B10H10Li(THF)](2) (E = S (12a), Se (12b)), which were confirmed by a crystal structure analysis. Reactions Of Cp'(2)Ln(mu-Cl)(2)Li(THF)(2) (1-10) with 12a or 12b gave dinuclear complexes of the formula [Li(THF)(4)](2)[Cp'(2)LnE(2)C(2)B(10)H(10)](2) (Cp'= eta(5)-t-BuC5H4, E = S, Ln = Nd (13a), Gd (14a), Dy (15a), Er (16a), Yb (17a); E = Se, Ln = Nd (13b), Gd (14b), Dy (15b), Er (16b), Yb (17b); Cp'= 1,3-eta(5)-t-Bu2C5H3 E = S, Ln = Nd (18a), Gd (19a), Dy (20a), Er (21a), Yb (22a); E = Se, Ln = Nd (18b), Gd (19b), Dy (20b), Er (21b), Yb (22b)). According to the X-ray structure analyses, the dianions of 13a and 13b contain two o-carborane dichalcogenolate bridges, and each CP'2Ln fragment is attached to one terminal and two bridging chalcogen ligands. The central Ln(2)E(2) four-membered ring is not planar, and the direct metal-metal interaction is absent.

Synthesis and characterization of novel lanthanocene complexes with dichalcogenolate o-carboranyl ligands

Reactions of [ Cp(2)Ln(mu-Cl)](2) (Cp = eta(5)-C5H5, Ln = Nd, Yb, Dy, Gd, Er) with an equivalent of [ (THF)(3)LiE2C2B10H10Li. (TT-IF) (THF)](2) (E = S, Se) in THF afforded the dinuclear sandwich complexes of formula[Cp(2)LnE(2)C(2)B(10)H(10)](2)[Li(THF)(4)](2) [E = S, Ln = Nd (1a), Yb (2a), Dy (3a), Gd (4a), Er (5a); E = Se, Ln = Nd (1b), Yb (2b), Dy (3b), Gd (4b), Er (5b)]. The molecular structures of complexes la, 2a and 2b were determined by the single crystal X-ray structure analyses. Two lanthanide atoms are connected by a pair chalcogen (eta(1), eta(2)-E2C2B10H10) bridging ligands and the central Ln(2)E(2) four membered ring is not planar.

Arabinogalactan as a carrier for contrast agent in magnetic resonance imaging

Arabinogalactan-Gd-DTPA was synthesized by the reaction of diethylenetriaminepenta-acetic acid (DTPA) bisanhydride with polysaccharide in dry DMSO and characterized by FTIR, elemental analysis and ICP-AES. Its stability was investigated by competition with Ca2+, EDTA, DTPA. The t(1)-relaxivity is 8.06 mmol(-1) . L . s(-1) in D2O, 8.48 mmol(-1) . L . s(-1) in 0.725 mmol . L-1 BSA, respectively. t(1)-weighted MR imaging of rat kidney and liver showed a remarkable enhancement post injection of Arabinogalactan-Gd-DTPA. The results indicate that the arabinogalactan-Gd-DTPA is a potential contrast agent for MRI.

Separation of heavy rare earth elements with extraction resin containing 1-hexyl-4-ethyloctyl isopropylphosphonic acid

This paper presents the results of the adsorption of heavy rare earth ions (Gd(III), Tb(III), Dy(III), Ho(III), Er(III), Tm(III), Yb(III), Lu(III) and Y(III)) from hydrochloric acid solutions at 30 degreesC by the extraction resin containing 1-hexyl-4-ethyloctyl isopropylphosphonic acid (HEOPPA), which has higher steric hindrance, higher selectivities and lower extraction and stripping acidity than di(2-ethylhexyl)phosphoric acid (DERPA) or 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (HEH/EHP). The dependence of acid concentration, flow rate and amounts of rare earth ions sorbed on the separation of Er-Tm, Tm-Yb and Er-Tm-Yb mixtures has been studied. The baseline chromatographic separation of Er-Tm-Yb mixture has been observed. Satisfactory results with purity and yield of Tm2O3>99.71% and >71.25%, Er2O3>99-81% and >94.17%, and Yb2O3>99.74% and >89.83%, respectively, have been obtained. The parameters such,as resolution, separation factors and efficiencies have been determined as a function of acidity, loading of rare earth elements and flow rates. The stoichiometry of the extraction of rare earth ions has been suggested as well.

An evaluation of gadolinium polyoxornetalates as possible MRI contrast agent

Two gadolinium polyoxometalates, K9GdW10O36 and K-11 [Gd(PW11O39)(2)], have been evaluated both in vivo and in vitro as candidates for tissue-specific MRI contrast agents. T-1-relaxivities of 6.89 mM(-1) . s(-1) for K9GdW10O36 and 5.27 mM(-1) . s(-1) for K-11[Gd(PW11O39)(2)] are slightly higher than that of the commercial MRI contrast agent (Gd-DTPA). Both compounds bind with bovine serum albumin and human serum transferrin and favorable liver-specific contrast enhancement in in vivo MRI with Sprague-Dawley rats after i.v. administration has been demonstrated. Imaging studies demonstrate that the two agents have a long residence time, showing MR signal enhancement in the liver for more than 40 min, longer than commercially available contrast agents. In vivo and in vitro assays showed that GdW10 and Gd(PW11)(2) are promising liver-specific MRI contrast agents and GdW10 may be used in the diagnosis of the pathological state. However, with the higher acute toxicity, the two gadolinium polyoxometalates need to be modified and studied further before clinical use.

Extraction kinetics of rare earth elements with sec-octylphenoxy acetic acid

The kinetics of RE (La, Gd, Er, Yb and Y) extraction with sec-octylphenoxy acetic acid was investigated using a constant interfacial area cell with laminar flow at 303 K. The natures of the extracted complexes have some effect on the extraction rate which is controlled by the reaction rate of M(III) and extractant molecules at two-phase interface for Er(III), Yb(III) and Y(III), by a mixed chemical reaction-diffusion for Gd(III) and a diffusion for La( III). The extractant molecules tend to adsorb at the interface. So an interfacial extraction reaction model was derived.

A novel way to enhance electroluminescence performance based on soluble binary and ternary europium 1,1,1-trifluoroacetylacetonate

Five rare earth complexes (Gd(acae)(3), Gd(TFacaC)(3), Eu(acaC)(3), Eu(TFacaC)(3) and Eu(TFacaC)(3)bipy; acac, acetylacetone; TFacac, 1,1,1-trifluoroacetylacetone; bipy, 2,2'-bipyridyl) were synthesized. By comparing the phosphorescence spectra of Gd(acac)(3) and Gd(TFacac)(3) the effect of the replacement of hydrogen by fluorine was examined. Organic light-emitting devices (OLEDs) based on the corresponding europium complexes as emissive layers were also fabricated by the spin-coating method. The triple-layer-type device with the structure glass substrate/ITO (indium-tin oxide)/PVK [poly(N-vinylcarbazole)]/(PVKEu)-Eu-.(TFacac)(3)bipy:PBD[2-(4-bibipyyl)-5-(4-t-butylbipyl-1,3,4-oxadiazole)]/PBD/Al (aluminum) exhibits a brighter red luminescence than those devices with Eu(acac)(3) and Eu(TFacac)(3) complexes as emissive centers upon applying a d.c. voltage.

Red electroluminescent device with europium 1,1,1-trifluoroacetylacetonate complex as emissive center

By comparing the phosphorescence spectra of Gd(acac)(3) (acac: acetylacetone) and Gd(TFacac)(3) (TFacac: 1, 1, 1-trifluoro-acetylacetone), the effect of fluorine replacing of hydrogen was discussed. It can lower the triplet state energy of acac and make it more suitable to the D-5(1) energy state of europium. Organic electroluminescent (OEL) devices with corresponding europium complexes as emissive layers were fabricated. A triple laver-type device with a structure of glass substrate/indium-tin oxide (ITO)/poly(N-vinylcarbazole) (PVK)/PVK:Eu(TFacac)(3)phen:2-(4-biphenyl)-5-(4-t-butylphenyl)-1,3,4-oxadiazole (PBD)/PBD/Al exhibits bright red luminescence upon applying dc voltage, The device has the properties of a diode and the current-bias voltage line was obtained.

PDP用荧光粉的真空紫外辐照特性

利用“等离子体显示用荧光粉光学测试系统”中147nm真空紫外光,对实用的（Y,Gd）BO_3:Eu红粉,Zn_2SiO_4:Mn和（Ba,Sr,Mg）O·nAl_2O_3:Mn绿粉以及（Ba,Mg）O·nAl_2O_3:Eu~(2+)蓝粉进行较长时间的辐照,以观察荧光粉的衰减特性,发现红粉衰减最小,蓝粉初始衰减较快,而绿粉亮度存在一个先升后降的现象。

三(环戊基茚基)钐配合物(C_5H_9C_9H_6)_3SmCl~-Li~+(THF)_4的合成与晶体结构

稀土配合物能使极性和非极性单体聚合[1] .虽然目前已测定了几乎所有的三 (环戊二烯基 )稀土配合物及部分三 (取代环戊二烯基 )稀土配合物的晶体结构 ,但有关三 (茚基 )稀土配合物的报道较少 .第一个三 (茚基 )稀土配合物是无水三氯化稀土与 3倍物质的量的茚基钠 C9H7Na在四氢呋喃中反应而得 ,但未报道其晶体结构[2 ] .后来用同样的反应却分离出以氯为桥的二聚体离子对配合物[Na( THF) 6][Ln( η5- C9H7) 3μ( Cl) Ln( η5- C9H7) 3]( Ln=Nd,Sm) [3] .无水三氯化稀土与 Mg( C9H7) 2 或C9H7K等物质的量反应则生成非溶剂化的 ( C9H7) 3Sm[4 ] ,而与茚基钠和环辛四烯钾 ( C8H8K)以 1∶ 2∶ 1物质的量比反应时 ,则得到 ( C9H7) 3Ln( THF) ( Ln=Nd,Gd) [5] .Bottomley[6] 曾用 ( C9Me7) K(七甲基茚基钾 )与 L n Cl3(物质的量比 3∶ 1 )反应制备 ( C9Me7) 3Nd( THF) 5和 ( C9Me7) 3Er· ( THF) 3,但未报道晶...