Rare earth disilicates R2Si2O7 (R = Gd, Tb, Dy, Ho): type B

2003 ◽  
Vol 218 (12) ◽  
Author(s):  
Michael E. Fleet ◽  
Xiaoyang Liu
Keyword(s):  
Rare Earth ◽  
Single Crystal ◽  
Rare Earth Element ◽  
Room Temperature ◽  
Earth Element ◽  
Type B ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature And Pressure

AbstractThe type B structure of the single rare earth element disilicates has been revised using room temperature and pressure single-crystal X-ray diffraction measurements on Gd

Rare-earth crystal chemistry of thalénite-(Y) from different environments

2018 ◽  
Vol 82 (2) ◽  
pp. 313-327
Author(s):  
Markus B. Raschke ◽  
Evan J. D. Anderson ◽  
Jason Van Fosson ◽  
Julien M. Allaz ◽  
Joseph R. Smyth ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Element ◽  
Earth Element ◽  
Spatial Scales ◽  
Structure Refinement ◽  
X Ray Diffraction ◽  
Heavy Rare Earth ◽  
Heavy Rare Earth Element ◽  
X Ray ◽  
Golden Horn

ABSTRACTThalénite-(Y), ideally Y3Si3O10F, is a heavy-rare-earth-rich silicate phase occurring in granite pegmatites that may help to illustrate rare-earth element (REE) chemistry and behaviour in natural systems. The crystal structure and mineral chemistry of thalénite-(Y) were analysed by electron microprobe analysis, X-ray diffraction and micro-Raman spectroscopy from a new locality in the peralkaline granite of the Golden Horn batholith, Okanogan County, Washington State, USA, in comparison with new analyses from the White Cloud pegmatite in the Pikes Peak batholith, Colorado, USA. The Golden Horn thalénite-(Y) occurs as late-stage sub-millimetre euhedral bladed transparent crystals in small miarolitic cavities in an arfvedsonite-bearing biotite granite. It exhibits growth zoning with distinct heavy-rare-earth element (HREE) vs. light-rare-earth element (LREE) enriched zones. The White Cloud thalénite-(Y) occurs in two distinct anhedral and botryoidal crystal habits of mostly homogenous composition. In addition, minor secondary thalénite-(Y) is recognized by its distinct Yb-rich composition (up to 0.8 atoms per formula unit (apfu) Yb). Single-crystal X-ray diffraction analysis and structure refinement reveals Y-site ordering with preferential HREE occupation of Y2 vs. Y1 and Y3 REE sites. Chondrite normalization shows continuous enrichment of HREE in White Cloud thalénite-(Y), in contrast to Golden Horn thalénite-(Y) with a slight depletion of the heaviest REE (Tm, Yb and Lu). The results suggest a hydrothermal origin of the Golden Horn miarolitic thalénite-(Y), compared to a combination of both primary magmatic followed by hydrothermal processes responsible for the multiple generations over a range of spatial scales in White Cloud thalénite-(Y).

Effect of Conjoint Additions of Rare Earth Element Oxides on the Phase Stability of Zirconia

1995 ◽  
Vol 412 ◽  
Author(s):  
Ewan R. Maddrell
Keyword(s):  
Solid Solution ◽  
Rare Earth ◽  
Rare Earth Element ◽  
Earth Element ◽  
Oxide Phase ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Zirconium Butoxide ◽  
Pyrochlore Type

AbstractThe ability of the cubic phase of zirconia to accommodate in solid solution the oxides of rare earth elements with differing cationic radii has been investigated. Mixed oxide phase assemblages were prepared by hydrolysing zirconium butoxide with solutions of rare earth element nitrates followed by drying, calcining and sintering. The resulting products were characterised by X-ray diffraction and energy dispersive spectroscopy. The cubic zirconia phase can accept into solid solution the larger, non-cubic stabilising, rare earth element ions such as lanthanum in the presence of the cubic stabilising oxides of yttrium and samarium. As the proportion of the larger rare earth element ions is increased the formation of pyrochlore type compounds is favoured.

ChemInform Abstract: SYNTHESIS AND X-RAY DIFFRACTION STUDY OF SOME NEW RARE EARTH ELEMENT SELENIDE IODIDES

1984 ◽  
Vol 15 (35) ◽  
Author(s):  
I. V. PROTSKAYA ◽  
V. A. TRIFONOV ◽  
B. A. POPOVKIN ◽  
A. V. NOVOSELOVA ◽  
S. I. TROYANOV ◽  
...  
Keyword(s):  
Rare Earth ◽  
Diffraction Study ◽  
Rare Earth Element ◽  
Earth Element ◽  
X Ray Diffraction ◽  
X Ray

Preparation of Ceria from Bastnaesite with NaHCO3 as Fluoride Retention Additive

2013 ◽  
Vol 477-478 ◽  
pp. 1423-1427
Author(s):  
Hui Zhong ◽  
Ke Hui Qiu ◽  
Yu Chong Qiu ◽  
Yu Tao Li ◽  
Ning Jia Fu
Keyword(s):  
Rare Earth ◽  
Hydrochloric Acid ◽  
Sodium Bicarbonate ◽  
Rare Earth Element ◽  
Earth Element ◽  
Rare Earth Oxide ◽  
Raw Material ◽  
X Ray Diffraction ◽  
X Ray ◽  
Impurity Elements

The CeO2 is prepared directly from bastnaesite as raw material that originated in Dechang, Sichuan province, China. Fully mixed with sodium bicarbonate (NaHCO3) and roasted at 550 °C, the rare earth element (REE) in bastnaesite transformed into rare earth oxide. And the CeO2 will be obtained by removing NaF through water washing and leaching the impurity elements including La, Fe, Al, Ca, etc. via hydrochloric acid (HCl). The CeO2 was characterized by X-ray diffraction (XRD) and X-ray fluorescence (XRF). The XRF results demonstrated that the content of CeO2 could reach more than 70% in products which can be used as polishing material.

The Stannides RE2Ni2Sn (RE = Pr, Ho, Er, Tm) – Structural Transition from the W2B2Co to the Mo2B2Fe Type as a Function of the Rare Earth Size

2013 ◽  
Vol 68 (1) ◽  
pp. 10-16 ◽  
Author(s):  
Birgit Heying ◽  
Ute Ch. Rodewald ◽  
Bernard Chevalier
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Single Crystal ◽  
Earth Element ◽  
Structural Transition ◽  
Structure Type ◽  
X Ray Diffraction ◽  
X Ray ◽  
Arc Melting ◽  
The Rare Earth

The stannides RE2Ni2Sn (RE=Pr, Ho, Er, Tm) were synthesized by arc-melting of the elements and characterized by powder X-ray diffraction. Pr2Ni2Sn crystallizes with the orthorhombic W2B2Co-type structure, Immm, a=443.8(1), b=572.1(1), c=855.1(2) pm, wR2=0.0693, 293 F2 values, 13 variables. A structural transition to the tetragonal Mo2B2Fe type occurs for the heavier rare earth elements. The structures of Ho2Ni2Sn (a=729.26(9), c=366.66(7) pm, wR2=0.0504, 250 F2 values, 12 variables), Er2Ni2Sn (a=727.2(2), c=364.3(1) pm, wR2=0.0397, 262 F2 values, 12 variables), and Tm2Ni2Sn (a=725.2(1), c=362.8(1) pm, wR2=0.0545, 258 F2 values, 12 variables) were refined from single-crystal diffractometer data. The switch in structure type is driven by the size of the rare earth element. The [Ni2Sn] substructures are composed of Ni2Sn2 squares and Ni4Sn2 hexagons in Pr2Ni2Sn, and of Ni3Sn2 pentagons in Er2Ni2Sn. The Ni4Sn2 hexagons and Ni3Sn2 pentagons exhibit Ni2 pairs with Ni-Ni distances of 247 pm in Pr2Ni2Sn, and of 250 pm in Er2Ni2Sn.

scholarly journals Corrosion and mechanical properties of AM50 magnesium alloy after modified by different amounts of rare earth element Gadolinium

Open Physics ◽  
2016 ◽  
Vol 14 (1) ◽  
pp. 444-451 ◽  
Author(s):  
Miao Yang ◽  
Zhiyi Zhang ◽  
Yaohui Liu ◽  
Xianlong Han
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Rare Earth ◽  
Magnesium Alloy ◽  
Rare Earth Element ◽  
Earth Element ◽  
Mechanical Stretch ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

AbstractTo improve the corrosion and mechanical properties of the AM50 magnesium alloy, different amounts of the rare earth element gadolinium were used. The microstructure, corrosion and mechanical properties were evaluated by X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, and electrochemical and mechanical stretch methods. The results indicate that, with Gd addition, the amount of the Al2Gd3 phase increased while the β-Mg17Al12 phase amount decreased. Due to the Gd addition, the grain of the AM50 magnesium alloy was significantly refined, which improved its tensile strength. Further, the decrease in the amount of the β phase improved the corrosion resistance of the alloy. The fracture mechanism of the Gd-modified AM50 magnesium alloy was a quasi-cleavage fracture. Finally, the optimum corrosion residual strength of the AM50 magnesium alloy occurred with 1 wt.%of added Gd.

Optical and Magnetic Properties of some REZnPnO (Pn = P, As, Sb) Phases

2010 ◽  
Vol 65 (10) ◽  
pp. 1191-1198 ◽  
Author(s):  
Inga Schellenberg ◽  
Hannes Lincke ◽  
Wilfried Hermes ◽  
Volker Dittrich ◽  
Robert Glaum ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Optical Properties ◽  
Rare Earth ◽  
Single Crystal ◽  
Rare Earth Element ◽  
Earth Element ◽  
Pure Form ◽  
X Ray ◽  
Optical And Magnetic Properties

Several REZnPnO phases of the ZrCuSiAs type (RE = rare earth element, Pn = P, As, Sb) were synthesized in X-ray-pure form in NaCl/KCl salt fluxes. The structure of PrZnSbO was refined from single-crystal diffractometer data: P4/nmm, a = 418.79(8), c = 946.7(5) pm, wR2 = 0.0349, 192 F2 values, 12 parameters. The REZnPnO pnictide oxides were studied with respect to magnetic susceptibility, 121Sb Mössbauer spectroscopy, and optical properties.

Coordination of rare earth element cations on the surface of silica-derived nanoadsorbents

2018 ◽  
Vol 47 (4) ◽  
pp. 1312-1320 ◽  
Author(s):  
E. Polido Legaria ◽  
I. Saldan ◽  
P. Svedlindh ◽  
E. Wetterskog ◽  
K. Gunnarsson ◽  
...  
Keyword(s):  
Rare Earth ◽  
Single Crystal ◽  
Rare Earth Element ◽  
Earth Element ◽  
Silica Particles ◽  
Exafs Spectroscopy ◽  
Functionalized Silica ◽  
Magnetic Studies ◽  
X Ray

The coordination of REE cations adsorbed on the surface of non-functionalized and complexone-functionalized silica particles was revealed by EXAFS spectroscopy and magnetic studies using X-ray single crystal models as a reference.

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