Enthalpies of Formation of Rare Earth and Actinide(III) Hydroxides; their Acid-Base Relationships and Estimation of their Thermodynamic Properties

1991 ◽  
Vol 257 ◽  
Author(s):  
Lester R. Morss ◽  
Clayton W. Williams
Keyword(s):  
Rare Earth ◽  
Solubility Product ◽  
Enthalpies Of Formation ◽  
Solution Stability ◽  
Acid Base ◽  
Environmental Interactions ◽  
Base Strength ◽  
Cell Volumes

ABSTRACTThis paper reviews the literature on rare earth(III) and actinide(III) hydroxide thermodynamics, in particular the determination of their enthalpies of formation at 25 ºC. The hydroxide unit-cell volumes, lanthanide/actinide ion sizes, and solid-solution stability trends have been correlated with a generalized acid-base strength model for oxides to estimate properties for heterogeneous equilibria that are relevant to nuclear waste modeling and to characterization of potential actinide environmental interactions. Enthalpies of formation and solubility-product constants of actinide(III) hydroxidesare estimated

Approaching the structure of REBaB9O16 (RE = rare earth) by characterization of a new analogue Ba6Bi9B79O138

2015 ◽  
Vol 3 (17) ◽  
pp. 4431-4437 ◽  
Author(s):  
Rihong Cong ◽  
Zhengyang Zhou ◽  
Qiaoqi Li ◽  
Junliang Sun ◽  
Jianhua Lin ◽  
...  
Keyword(s):  
Rare Earth ◽  
Structure Determination

The structure determination of Ba6Bi9B79O138 uncovers the mystery of the crystallography of the well-known phosphors REBaB9O16 (RE = rare earth).

Barium Rare Earth Titanates: X-Ray Characterization of BaR2Ti3O10 and BaR2Ti4O12: R = Lanthanide

1992 ◽  
Vol 7 (3) ◽  
pp. 176-178 ◽  
Author(s):  
X. Jing ◽  
C. Zheng ◽  
A.R. West
Keyword(s):  
Rare Earth ◽  
Solid State ◽  
Unit Cell ◽  
Lanthanide Ion ◽  
X Ray ◽  
Ion Size ◽  
Cell Data ◽  
Unit Cell Data ◽  
Cell Volumes

AbstractThe compounds, BaR2Ti3O10: R = La, Pr, Nd and Sm; BaR2Ti4O12: R = La, Pr, Sm, Gd, Eu have been prepared by solid state reaction and characterized by X-ray powder diffraction. Unit cell data are summarised; lattice parameters and unit cell volumes increase approximately linearly with lanthanide ion size.

Determination of standard molar enthalpies of formation for rare earth isothiocyanate hydrates

1988 ◽  
Vol 123 ◽  
pp. 43-50 ◽  
Author(s):  
Jing-Zhi Yin ◽  
Ben-Gao Jiang ◽  
Tong-Shan Sun ◽  
Yu-Feng Liu
Keyword(s):  
Rare Earth ◽  
Enthalpies Of Formation

Energetics of oxidation of RE–Si–Al–O–N glasses

2003 ◽  
Vol 18 (7) ◽  
pp. 1607-1613 ◽  
Author(s):  
Yahong Zhang ◽  
Alexandra Navrotsky ◽  
Dirk Matusch ◽  
Hans Jürgen Seifert
Keyword(s):  
Glass Transition ◽  
Rare Earth ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Nitrogen Content ◽  
Ionic Radius ◽  
Composition Range ◽  
Enthalpies Of Formation ◽  
Acid Base ◽  
Nitrogen Ions

Enthalpies of drop solution in molten 52 wt.% LiBO2-48 wt.% NaBO2 at 1078 K were measured for RE1.1Si1.7Al0.6O6-1.5xNx (x = 0, 0.2, 0.4, 0.6, 0.8) glasses for RE = Nd, Gd, Dy, Er, and Y. Linear relations between enthalpies of formation from elements and nitrogen content indicate that, within the experimental composition range, sites occupied by nitrogen ions are approximately equivalent in energy for a given substitutional series. The energetics of different rare-earth SiAlON glasses appears to be dominated by differences in the acid/base character of the cations. The onset glass-transition temperature increases linearly with increasing nitrogen content for the same rare earth and with decreasing rare-earth ionic radius for the same nitrogen content.

Structural Systematics of Rare Earth Complexes. III. Structural Characterization of Lanthanoid(III) Picrate Hydrates: Gadolinium Picrate Dodecahydrate—an X-Ray-Induced Phase Modification?—and Some General Aspects of the Structural Chemistry of Lanthanoid Picrates

1994 ◽  
Vol 47 (2) ◽  
pp. 349 ◽  
Author(s):  
JM Harrowfield ◽  
WM Lu ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Rare Earth ◽  
Data Collection ◽  
Structure Type ◽  
Data Sets ◽  
Fresh Sample ◽  
X Ray ◽  
Phase Modification ◽  
General Aspects

In the course of the studies described in Parts I and II, an unusual result was observed in the case of the structure determination of hydrated gadolinium(III) picrate. Midway through data collection, the monoclinic P 21/c phase underwent a phase modification (X-ray-induced?) to a similar cell more nearly resembling that of the La → Pr structure type recorded previously, with no loss of crystal integrity, and with useful data sets being obtained on both forms. Redetermination of the structure with a fresh sample yielded no reproduction of the anomaly. These results are recorded and discussed, together with an overview of the consequences of the data of Parts I-III in relation to those of other literature in the field.

scholarly journals Characterization of Polymer Surfaces by the Use of Different Wetting Theories Regarding Acid-Base Properties

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Eduard Kraus ◽  
Lukas Orf ◽  
Michael Heilig ◽  
Benjamin Baudrit ◽  
Irina Starostina ◽  
...  
Keyword(s):  
Polymer Surfaces ◽  
Solid Surfaces ◽  
Solid Polymer ◽  
Acid Base ◽  
Polymer Interactions ◽  
Spatial Equation ◽  
Plastic Surfaces ◽  
Base Properties

The existing wetting methods for the determination of acid-base properties on solid surfaces are discussed. Striving for a better understanding of the adhesive polymer interactions in adhesively joined polymers, the methods of Berger and van Oss-Chaudhury-Good were found as the most suitable methods for the investigation of wetting on solid polymer surfaces. Methods of nonlinear systems by Della Volpe and Siboni were adapted and evaluated on plastic surfaces. In the context of these investigations various data of the surface free energy as well as its components have been identified for a number of polymer surfaces by application of spatial equation solutions.

Synthesis and structure determination of seven ternary bismuthides: crystal chemistry of theRELi3Bi2family (RE= La–Nd, Sm, Gd, and Tb)

2015 ◽  
Vol 71 (10) ◽  
pp. 894-899 ◽  
Author(s):  
Jai Prakash ◽  
Marion C. Schäfer ◽  
Svilen Bobev
Keyword(s):  
Rare Earth ◽  
Rare Earth Metal ◽  
Earth Metal ◽  
X Ray Diffraction ◽  
Zintl Phases ◽  
Tetrahedral Geometry ◽  
X Ray ◽  
Pearson Symbol ◽  
Cell Volumes

Zintl phases are renowned for their diverse crystal structures with rich structural chemistry and have recently exhibited some remarkable heat- and charge-transport properties. The ternary bismuthidesRELi3Bi2(RE= La–Nd, Sm, Gd, and Tb) (namely, lanthanum trilithium dibismuthide, LaLi3Bi2, cerium trilithium dibismuthide, CeLi3Bi2, praseodymium trilithium dibismuthide, PrLi3Bi2, neodymium trilithium dibismuthide, NdLi3Bi2, samarium trilithium dibismuthide, SmLi3Bi2, gadolinium trilithium dibismuthide, GdLi3Bi2, and terbium trilithium dibismuthide, TbLi3Bi2) were synthesized by high-temperature reactions of the elements in sealed Nb ampoules. Single-crystal X-ray diffraction analysis shows that all seven compounds are isostructural and crystallize in the LaLi3Sb2type structure in the trigonal space groupP\overline{3}m1 (Pearson symbolhP6). The unit-cell volumes decrease monotonically on moving from the La to the Tb compound, owing to the lanthanide contraction. The structure features a rare-earth metal atom and one Li atom in a nearly perfect octahedral coordination by six Bi atoms. The second crystallographically unique Li atom is surrounded by four Bi atoms in a slightly distorted tetrahedral geometry. The atomic arrangements are best described as layered structures consisting of two-dimensional layers of fused LiBi4tetrahedra and LiBi6octahedra, separated by rare-earth metal cations. As such, these compounds are expected to be valance-precise semiconductors, whose formulae can be represented as (RE3+)(Li1+)3(Bi3−)2.

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