13765-25-8Relevant articles and documents
Fabrication of EuF3-mesocrystals in a gel matrix
Lausser, Christine,Kumke, Michael U.,Antonietti, Markus,Coelfen, Helmut
, p. 1925 - 1930 (2010)
Europium(III) fluoride mesocrystals were synthesised in an organic matrix. This matrix is a gel formed by Eu3+ ions and a polycar-boxylate/ sulfonate copolymer, ACUSOL 588G. In the gel phase, the local amount of europium ions is very high since Eu3+ acts as a cross-linker, and crystallisation occurs upon addition of F-. Nucleated seed crystals in the gel phase grow by further ion attachment and form mesocrystals by mutual orientation of the EuF3 particles in the gel. We propose a dipole field as reason for this alignment and that the dipolar character of the particles originates from adsorption of the polyelectro-lyte on charged crystal faces.
Facile preparation of quantum cutting GdF3:Eu3+ nanoparticles from ionic liquids
Lorbeer, Chantal,Cybinska, Joanna,Mudring, Anja-Verena
, p. 571 - 573 (2010)
Microwave reaction of Ln(OAc)3·xH2O, Ln = Gd, Eu; OAc = acetate) with and in the ionic liquid [C4mim][BF 4] (C4mim = 1-butyl-3-methylimidazolium) allows the fast and efficient synthesis of small, uniform, oxygen-free lanthanide nanofluorides with excellent photophysical behaviour. For GdF3:Eu3+ nanoparticles a quantum efficiency of up to 145% was determined.
Localization of Eu3+ in KGd1.9Eu0.1F7 and KGd1.9Eu0.1F6.97O0.015 by site-selective excitation and time-resolved spectroscopy
Pierrard,Gredin,Dupont,De Kozak,Piriou
, p. 71 - 80 (1999)
This paper reports site-selective excitation (or observation) and time-resolved spectroscopy of the host matrices KGd2F7 and KGd2F6.97O0.015 doped by Eu3+. The crystal structure of KGd2F7 derives from that of the fluorite-type, by an ordering of the cations and anions. The luminescence spectra and site-selective excitation in the 5D0→7F0 region, have allowed to identify several distributions of discrete sites for the Eu3+ ions, in which two sites are characterized by unusual spectra which are attributed to Eu-O bonds. Another kind of site, characteristic of fluorinated surroundings close to the centrosymmetry, exhibits a very long lifetime (6.8 ms) of the 5D0 level. Although the accurate structures of these compounds are not yet known, they are very close to that of KGd2.77F9.32 previously solved and the spectroscopic results are in agreement with the number and the symmetries of the rare earth crystallographic sites.
Nanocrystals of cerium and europium trifluorides generated by coaxial Taylor cone electrospray of aqueous solutions at room temperature
De Carcer, I. Aguirre,Herrero,Landa-Canovas,Sobolev
, (2005)
Cerium and europium trifluoride nanocrystals have been obtained in a Taylor's double-cone electrospray by chemical reactions of precipitation from two miscible aqueous solutions of rare earth (RE=Ce,Eu) nitrates and HF. The products of the chemical reactions CeF3 and EuF3 have a very low solubility precipitating as nanocrystals of controllable size and composition. The change of the starting concentration, from 0.13 M Ce(NO 3)3 to 0.01 M Eu(NO3)3, seems to have influence on the morphology of the nanoparticles, producing well crystallized EuF3 nanocrystals for the dilute solution and mosaic-like multidomain CeF3 nanocrystals for the more concentrated solution. This procedure can be used for the production of a great variety of inorganic compounds. The low-solubility requirement of the products of chemical reactions is the only key and it assures a high rate of insoluble crystals formation.
The new carbodiimide Li2Gd2Sr(CN2) 5 having a crystal structure related to that of Gd 2(CN2)3
Unverfehrt, Leonid,Stroebele, Markus,Meyer, H.-Juergen
, p. 84 - 88 (2013/03/28)
The new carbodiimide compounds Li2RE2Sr(CN 2)5 (RE = Sm, Gd, Eu, Tb) were prepared by a straight forward solid state metathesis reaction of REF3, SrF2, and Li2(CN2) at around 600 °C. The crystal structure of Li2Gd2Sr(CN2)5 was solved based on X-ray single-crystal diffraction data. Corresponding Li2RE 2Sr(CN2)5 compounds were analyzed by isotypic indexing of their powder patterns. The crystal structure of Li 2Gd2Sr(CN2)5 can be well related to that of Gd2(CN2)3, because both structures are based on layered structures composed of close packed layers of [N=C=N] 2- sticks, alternating with layers of metal ions. The crystal structure of Li2Gd2Sr(CN2)5 can be considered to contain an ABC layer sequence of [N = C=N]2- layers with the interlayer voids being occupied by (three) distinct types of cations. Copyright
Synthesis and optical properties of non-stoichiometric lanthanide (Sm, Eu, Tm, Yb) fluorides
Ivanenko,Kompanichenko,Omelchuk,Zinchenko,Timukhin
, p. 841 - 847 (2010/09/17)
Nonstoichiometric samarium, europium, ytterbium, and thulium fluorides were prepared by reduction of the corresponding trifluorides with the same lanthanide metal or silicon. Crystal lattice type and lattice parameters of the compounds were determined by
