Crystal structures of the penta- and hexahydrate of thulium nitrate

Tm(NO3)3·5H2O and Tm(NO3)3·6H2O, or more precisely [Tm(NO3)3(H2O)4]·H2O and [Tm(NO3)3(H2O)4]·2H2O, respectively, have been obtained from a concentrated solution of Tm2O3 in HNO3. The crystal structures of the two hydrates show strong similarities as both crystallize in space group P\overline{1} with all atoms at general positions and contain neutral, molecular [Tm(NO3)3(H2O)4] complexes, i.e. ten-coordinated TmIII cations with three nitrate anions as bidentate ligands and four coordinating water molecules, and one or two additional crystal water molecules, respectively. All building units are connected by medium–strong to weak O—H...O hydrogen bonds. Tm(NO3)3·6H2O represents the maximally hydrated thulium nitrate as well as the heaviest rare earth nitrate hexahydrate known to date.

Synthesis and Property Investigation on the Spherical Lu3Al5O12:Tb3+ Phosphor with Green Emitting

Spherical phosphors of (Lu1-xTbx)3Al5O12 [(Lu1-xTbx)AG] have been obtained through homogeneous precipitation method using urea as the precipitant and rare earth nitrate as mother salts. The synthesis, phase evolution and photoluminescent properties of the (Lu1-xTbx)AG phosphors were tested by XRD, FE-SEM, PLE/PL, and fluorescence decay analysis. The phase pure (Lu1-xTbx)AG garnets were formed at 1100 °C or higher temperatures. The phosphors exhibited strong green emissions at ~545 nm (the 5D4→7F5 transitions of Tb3+) under ~276 nm excitation. The CIE chromaticity coordinates and color temperature were determined to be (~0.36, ~0.56) and ~5100 K, respectively. The intensity of 545 nm emission increased with the Tb3+ content increasing to 7 at%, and then gradually decreases owing to the concentration quenching. The lifetime of 545 nm emission decreases at a higher Tb3+ addition. The spherical (Lu1-xTbx)AG garnet phosphors developed in the this work were expected to be widely used in lighting and displaying areas.

Investigation on the Preparation and Properties of Monodispersed Spherical Y2O3:Dy3+ Phosphor

The oxide phosphor (Y1-xDyx)2O3(x=0-0.1) was obtained by calcining their respective precursors synthesized by homogeneous precipitation technique using rare earth nitrate as mother salt and urea as precipitating agent. The particle shape/size, fluorescent properties (especially the influence of Dy3+ concentration and calcination temperature) of the product was studied in detail. The results showed that the precursors exhibit monodisperse spherical morphology whose size can be controlled by adjusting the urea content. The phase pure (Y1-xDyx)2O3 can be obtained by calcining precursor at least 600 °C, and the monodisperse spherical morphology can be kept at even high temperature of 1000 °C. The (Y1-xDyx)2O3 phosphors exhibit strong yellow emission at ~577 nm (4F9/2→6H13/2 transition of Dy3+) and blue emission at ~491 nm (4F9/2→6H15/2 transition of Dy3+) upon optimal excitation wavelength of ~352 nm. The quenching concentration of Dy3+ was determined to be ~2 at% (x=0.02). The emission intensity of (Y1-xDyx)2O3 phosphors can be improved with the temperature and particle size increasing

The Rare Earth Metals and Their Compounds: Thermal Analysis of Rare Earth Nitrate Mixtures

A method of analysis is proposed which utilizes thecharacteristic melting points of the hydrated salts andthe liquidus curves of the binary salt mixtures for theestimation of the composition of rare earth mixtures.Several binary salt systems were investigated, employingvery pure simple and double rare earth nitrates toprovide basic information concerning the possibilitiesof the method.

Ultra-Large Unilamellar Nanosheets Efficiently Exfoliated from (Y0.95Eu0.05)2(OH)5NO3·nH2O and their Self-Assembly into Oriented Oxide Film with Enhanced Photoluminescence Properties

Two dimensional nanophosphors of high quality play an important role in the miniaturization and intelligentization of opto-electronic components. In this present work, ultra-large (30μm) single crystals of (Y0.95Eu0.05)2(OH)5NO3·nH2O layered rare earth hydroxide (LRH) with a hexagonal shape have been synthisized via autoclaving the rare-earth nitrate/NH4OH reaction system in the presence of ammonium nitrate (NH4NO3). The nitrate ions, existing in the interlayer gallery of layered rare earth hydroxide, exhibit facile exchanges with oleate anions by hydrothermal anion exchange. Furthermore, the interlayer distance can thus be expanded from ~0.9 nm for the pristine LRHs to ~3.60 nm for the intercalated ones, which are then efficiently delaminated into unilamellar nanosheets with a lateral size of 10μm and a thickness of ~1.50 nm. The obtained nanosheets are single crystaline. Highly [11 oriented, dense (Y0.95Eu0.05)2O3 phosphor films with excellent optical transparency and a greatly enhanced luminescence intensity have been constructed via self-assembly of ultra-large unilamellar LRH nanosheets, followed by proper annealing.

Phosphatization Coating-Forming Mechanism Based on Green Phosphating Accelerator Rare Earth Nitrate

Experimental results show that the samples gained in bath added Rare earth nitrate (REN), relative to the sample got in bath without REN, improve the anti-corrosion power of the coating because of increasing of covering rate of formless crystal Zn2Fe(PO4)2·4H2O (marked P) crystals and the ratio of P/(P+H) (H is the mark of Zn3(PO4)2 crystal) in the coating, combination of which with components parsing by EDS indicates that the sequence of contribution elements P and Zn to erosion resistance of coatings is P>Zn. And the correlative mechanism was discussed, which has it clear that RE is materially a catalyst holding excellent ability of carrying oxygen and cathode depolarization, its concentration gets so constant in certain range that it is much steadier and more efficient than the usual consumptive oxidants like nitrates. In a word, REN plays the role of surface regulator, accelerant and densification agent, which speeds up the phosphating, and bids it effective to enhance the anti-corrosion power of the coating. The addition of REN, not only promote the phosphating film formation and substantial reduction or exemption of nitrite. So, REN is green phosphating accelerator of live up to one's name.