Search results for "Praseodymium"
showing 10 items of 31 documents
Polymorphism of praseodymium orthovanadate under high pressure
2021
Zircon-type $\mathrm{PrV}{\mathrm{O}}_{4}$ has been studied at high pressures and room temperature by means of synchrotron powder x-ray diffraction. At room temperature, we observed the previously known zircon-to-monazite phase transition at 5.5(4) GPa and a second phase transition from monazite to a monoclinic structure at 12.7(8) GPa, which we identified as a $\mathrm{PbW}{\mathrm{O}}_{4}$-III-type phase. This conclusion is supported by our ab initio calculations, which also predict a scheelite-type phase to be stable at high pressure. Motivated by this finding, we subjected zircon-type $\mathrm{PrV}{\mathrm{O}}_{4}$ samples to high pressure (7 GPa) and temperature (600, 800, and 1000 \if…
Transition probabilities of PrII-lines emitted from a ferroelectric plasma source
1991
Abstract An argon-praseodymium plasma was generated under atmospheric pressure between a ceramic ferroelectric plate and a praseodymium plate. The system of plates was connected to an acoustic frequency supply. The plasma radiation was analyzed in the spectral range from 2000 to 7000 A by using a grating spectrograph with a linear dispersion near 1 mm/A, adopted to photoelectric measurements. The emission spectrum of praseodymium was recorded and the intensities of a few hundred lines were measured. Transition probabilities were determined for 62PrII-lines, using available lifetime data for excited levels and measured branching ratios of the corresponding lines. Reasonable agreement has bee…
Monolacunary Keggin polyoxometalates connected to ten 4d or 4f metal atoms.
2013
The rational self-assembly of mono-lacunary Keggin clusters with 4d and 4f metal salts via a conventional method has yielded two novel polyoxometalate-based 4d-4f heterometallic compounds containing lacunary Keggin anions connected to ten metal atoms: {[Ag{Ag2(H2O)4}{Ln(H2O)6}2H ⊂ {SiW11Ln(H2O)4O39}2]·nH2O (Ln = Ce and n = 7 for 1, Ln = Pr and n = 3 for 2). Their structures were determined by single crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra, and thermogravimetric (TG) analyses. A structural feature in 1 and 2 is that each [SiW11O39](8-) cluster (SiW11) is connected to ten metals (five Ag(+) and five Ln(3+) cations), representing the highe…
Electrochemical characterization of praseodymia doped zircon. Catalytic effect on the electrochemical reduction of molecular oxygen in polar organic …
2011
The voltammetry of microparticles and scanning electrochemical microscopy methodologies are applied to characterize praseodymium centers in praseodymia-doped zircon (PrxZr(1−y)Si(1−z)O4; y + z = x; 0.02 < x < 0.10) specimens prepared via sol–gel synthetic routes. In contact with aqueous electrolytes, two overlapping Pr-centered cathodic processes, attributable to the Pr (IV) to Pr (III) reduction of Pr centers in different sites are obtained. In water-containing, air-saturated acetone and DMSO solutions as solvent, PrxZr(1−y)Si(1−z)O4 materials produce a significant catalytic effect on the electrochemical reduction of peroxide radical anion electrochemically generated. These electrochemical…
CCDC 928289: Experimental Crystal Structure Determination
2014
Related Article: D.Bubrin,M.Niemeyer|2014|Inorg.Chem.|53|1269|doi:10.1021/ic402941z
CCDC 801152: Experimental Crystal Structure Determination
2011
Related Article: A.Jana, S.Majumder, L.Carrella, M.Nayak, T.Weyhermueller, S.Dutta, D.Schollmeyer, E.Rentschler, R.Koner, S.Mohanta|2010|Inorg.Chem.|49|9012|doi:10.1021/ic101445n
CCDC 883544: Experimental Crystal Structure Determination
2012
Related Article: J.Vallejo, J.Cano, I.Castro, M.Julve, F.Lloret, O.Fabelo, L.Canadillas-Delgado, E.Pardo|2012|Chem.Commun.|48|7726|doi:10.1039/c2cc33674j
CCDC 152118: Experimental Crystal Structure Determination
2001
Related Article: M.Hernandez-Molina, P.A.Lorenzo-Luis, T.Lopez, C.Ruiz-Perez, F.Lloret, M.Julve|2000|CrystEngComm|2|169|doi:10.1039/b006256l
CCDC 958836: Experimental Crystal Structure Determination
2014
Related Article: Pau Díaz-Gallifa, Oscar Fabelo, Laura Cañadillas-Delgado, Jorge Pasán, Ana Labrador, Francesc Lloret, Miguel Julve, and Catalina Ruiz-Pérez|2013|Cryst.Growth Des.|13|4735|doi:10.1021/cg4008679
CCDC 1510396: Experimental Crystal Structure Determination
2017
Related Article: Maria Vanda Marinho, Daniella O. Reis, Willian X. C. Oliveira, Lippy F. Marques, Humberto O. Stumpf, Mariadel Déniz, Jorge Pasán, Catalina Ruiz-Pérez, Joan Cano, Francesc Lloret, and Miguel Julve|2017|Inorg.Chem.|56|2108|doi:10.1021/acs.inorgchem.6b02774