A New Synthesis Method for Lithium Tantalate Charge Doped with Rare-Earth Elements

2020 ◽  
Vol 310 ◽  
pp. 53-57
Author(s):  
Sofia M. Masloboeva ◽  
Mikhail N. Palatnikov ◽  
Larisa G. Arutyunyan
Keyword(s):  
Rare Earth ◽  
Thermal Treatment ◽  
Rare Earth Elements ◽  
Single Crystal ◽  
Single Phase ◽  
Synthesis Method ◽  
Lithium Tantalate ◽  
New Synthesis ◽  
Citrate Precursor ◽  
Functional Ceramics

A method was developed for synthesis of a single phase lithium tantalate charge doped by rare earth elements (TR) from highly pure solutions containing tantalum. The method is based on obtaining and thermal treatment of citrate precursor containing Li, Ta and TR. Charge samples were obtained due to suggested technological scheme; the dopant had given concentration and was chemically uniformly distributed. The charge can be applied both in single crystal growing technology and at obtaining of functional ceramics based on LiTaO3:TR.

Platinum-Germanium Ordering in the Germanides REPtGe with the Heavy Rare Earth Elements

2009 ◽  
Vol 64 (4) ◽  
pp. 383-387 ◽  
Author(s):  
Ute Ch. Rodewald ◽  
Birgit Heying ◽  
Rolf-Dieter Hoffmann ◽  
Dirk Niepmann ◽  
Rainer Pöttgen
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Single Crystal ◽  
Three Dimensional ◽  
Type Structure ◽  
Crystal Chemical ◽  
Heavy Rare Earth ◽  
Structure Space ◽  
Arc Melting ◽  
Heavy Rare Earth Elements

The equiatomic germanides REPtGe with the heavy rare earth elements (RE) have been reinvestigated with respect to platinum-germanium ordering. The compounds were prepared by arc-melting of the elements followed by annealing for two weeks at 1070 K. The REPtGe germanides crystallize with the TiNiSi-type structure, space group Pnma. The structures of ErPtGe (a = 692.01(5), b = 432.03(4), c = 753.19(5) pm, wR2 = 0.0523, 435 F2, 20 variables) and the new germanide LuPtGe (a = 683.1(1), b = 429.2(1), c = 750.3(1) pm, wR2 = 0.0696, 358 F2, 20 variables) have been refined from single crystal diffractometer data. These structures exhibit three-dimensional [PtGe] networks with strong Pt-Ge intra- (251 - 255 pm in LuPtGe) and weaker interlayer (272 pm in LuPtGe) interactions. The crystal chemical peculiarities of the whole REPtGe series are briefly discussed.

Zirconia – A Ceramic for Excess weapons Plutonium Wastes

1999 ◽  
Vol 556 ◽  
Author(s):  
W. L. Gong ◽  
W. Lutze ◽  
R. C. Ewing
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Metal Oxides ◽  
Solid Solutions ◽  
Binary Systems ◽  
Single Phase ◽  
Sol Gel ◽  
Neutron Absorber ◽  
Cubic Zirconia

AbstractWe synthesized a ceramic containing simulated excess weapons plutonium waste in solidsolution with zirconia (ZrO2)ss. ZrO2 has a large solubility for other metal oxides. More thantwenty binary systems AxOy- ZrO2 have been reported in the literature, including PuG2, rare earth elements, and oxides of metals contained in weapons plutonium wastes. We show that significant amounts of gadolinium (neutron absorber) and yttrium (stabilizer of the cubic modification) can be dissolved in ZrO2, together with plutonium (simulated by Th4+, Ce4+, or U4+) and impurities (e.g., Ca Mg, Fe, Si). Sol-gel and powder methods were applied to make homogeneous, single phase zirconia solid solutions. Pu waste impurities were completely dissolved in the solid solutions. In contrast to other phases, e.g., zirconolite and pyrochlore, yttrium stabilized cubic zirconia does not undergo amorphization upon irradiation.

scholarly journals Zr-Rich Eudialyte from the Lovozero Peralkaline Massif, Kola Peninsula, Russia

Minerals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 982
Author(s):  
Taras L. Panikorovskii ◽  
Julia A. Mikhailova ◽  
Yakov A. Pakhomovsky ◽  
Ayya V. Bazai ◽  
Sergey M. Aksenov ◽  
...  
Keyword(s):  
Rare Earth ◽  
Chemical Composition ◽  
Rare Earth Elements ◽  
Single Crystal ◽  
Kola Peninsula ◽  
Marginal Zone ◽  
X Ray Diffraction ◽  
Eudialyte Group ◽  
X Ray ◽  
Marginal Zones

The Lovozero peralkaline massif (Kola Peninsula, Russia) has several deposits of Zr, Nb, Ta and rare earth elements (REE) associated with eudialyte-group minerals (EGM). Eudialyte from the Alluaiv Mt. often forms zonal grains with central parts enriched in Zr (more than 3 apfu) and marginal zones enriched in REEs. The detailed study of the chemical composition (294 microprobe analyses) of EGMs from the drill cores of the Mt. Alluaiv-Mt. Kedykvyrpakhk deposits reveal more than 70% Zr-enriched samples. Single-crystal X-ray diffraction (XRD) was performed separately for the Zr-rich (4.17 Zr apfu) core and the REE-rich (0.54 REE apfu) marginal zone. It was found that extra Zr incorporates into the octahedral M1A site, where it replaces Ca, leading to the symmetry lowering from R3¯m to R32. We demonstrated that the incorporation of extra Zr into EGMs makes the calculation of the eudialyte formula on the basis of Si + Al + Zr + Ti + Hf + Nb + Ta + W = 29 apfu inappropriate.

scholarly journals A Review on Luminescent Rare Earth Complexes

2021 ◽  
pp. 69-77
Author(s):  
Qiuxin ShenQiuxin Shen ◽  
Liting Xu ◽  
Yiyan Jiang ◽  
Yiping Zhang
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Solid Phase ◽  
Synthesis Method ◽  
Rare Earth Complexes ◽  
Precipitation Method ◽  
Future Research ◽  
Phase Method ◽  
Synthesis Methods ◽  
Starting Point

At present, rare earth elements are widely used in various industries. In this paper, luminescent rare earth complexes are taken as a starting point to explore the luminescence principles of several important rare earth elements. The commonly used synthesis methods of luminescent rare earth complexes in recent year are also summarized, mainly including co-precipitation method, high temperature solid phase method, sol-gel method and hydrothermal synthesis method. And prospects for the future research on luminescent rare earth complexes are made.

The quaternary arsenide oxides Ce9Au5–xAs8O6 and Pr9Au5–xAs8O6

2016 ◽  
Vol 71 (12) ◽  
pp. 1245-1252
Author(s):  
Timo Bartsch ◽  
Rolf-Dieter Hoffmann ◽  
Rainer Pöttgen
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Single Crystal ◽  
Crystal Chemistry ◽  
Structure Type ◽  
Rare Earth Oxides ◽  
Gold Powder ◽  
X Ray ◽  
Annealing Temperatures ◽  
Oxide Crystal

AbstractThe quaternary gold arsenide oxides Ce9Au5−xAs8O6 and Pr9Au5−xAs8O6 were synthesized from the rare earth elements (RE), rare earth oxides, arsenic and gold powder at maximum annealing temperatures of 1173 K. The structures were refined from single crystal X-ray diffractometer data: Pnnm, a=1321.64(6) pm, b=4073.0(3), c=423.96(2), wR2=0.0842, 3106 F2 values, 160 variables for Ce9Au4.91(4)As8O6 and Pnnm, a=1315.01(4), b=4052.87(8), c=420.68(1) pm, wR2=0.0865, 5313 F2 values, 160 variables for Pr9Au4.75(1)As8O6. They represent a new structure type and show a further extension of pnictide oxide crystal chemistry. A complex polyanionic gold arsenide network [Au5As8]15− (with some disorder in the gold substructure) is charge compensated with polycationic strands of condensed edge-sharing O@RE4/4 and O@RE4/3 tetrahedra ([RE4O3]212+) as well as RE3+ cations in cavities.

Quaternary Equiatomic Manganese Pnictide Oxides AMnPO (A = La-Nd, Sm, Gd-Dy), AMnAsO (A = Y, La-Nd, Sm, Gd-Dy, U), and AMnSbO (A = La-Nd, Sm, Gd) with ZrCuSiAs Type Structure

1997 ◽  
Vol 52 (5) ◽  
pp. 560-564 ◽  
Author(s):  
Andre T. Nientiedt ◽  
Wolfgang Jeitschko ◽  
Peter G. Pollmeier ◽  
Markus Brylak
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Single Crystal ◽  
Chemical Bonding ◽  
Type Structure ◽  
Variable Parameters ◽  
X Ray ◽  
Structure Factors ◽  
The Rare Earth

Abstract The 24 title compounds were prepared in well crystallized form by reaction of the rare earth elements (or uranium, respectively), manganese, the pnictide components, and MnO2 in a NaCl/KCl flux. They crystallize with the tetragonal ZrCuSiAs type structure (P4/nmm, Z = 2), which has been refined from single-crystal X-ray data of NdMnPO (a = 398.9(1), c = 867.4(1) pm, R = 0.026), NdMnAsO (a = 404,9(2), c = 889.3(4) pm, R = 0.025), and NdMnSbO (a = 416.5(1), c = 946.2(2) pm, R = 0.021) for 107, 190, and 124 structure factors, respectively, and 11 variable parameters each. Chemical bonding in these compounds is briefly discussed.

Study of Polymorphs of Zirconia in the System ZrO2: ƞ wt% Re2O3 Obtained by Polymeric Precursor Method

2012 ◽  
Vol 727-728 ◽  
pp. 1340-1344
Author(s):  
R.A. Muñoz ◽  
J.E. Rodriguez ◽  
Cosme Roberto Moreira Silva
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Zirconium Oxide ◽  
Pechini Method ◽  
Synthesis Method ◽  
Raw Material ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Dysprosium Oxide ◽  
Transmission Electron

In this paper we propose the stabilization of zirconium oxide with controlled additions of a rare earth elements concentrate, in the system ZrO2: ƞ wt% Re2O3 (withƞ=5.36, 10.47, 13.74, 16.91 e 20) whereRe2O3is a rare earth elements concentrate composed mainly of 76.88% of yttrium oxide, 12.1% of Dysprosium oxide, 4.04% of Erbium oxide and 1.94% of Holmium oxide. The synthesis method used was the Pechini method. The results show that additions of 5.36 and 20 wt% of the concentrate are enough to stabilize the tetragonal and cubic zirconia phases respectively, and that zirconium oxide polymorphs can coexist with additions within these limit. In the characterization of the obtained powders are presented and discussed the following results: differential scanning calorimetry, transmission electron microscopy and X-ray diffraction. Also, it was necessary to make analysis by Rietveld refinement because they had severe overlap in the diffraction peaks. One of the most relevant results is obtaining a raw material, cheap to be used in many technological applications.

Preparation and Crystal Structure of the Isotypic Carbides Ln3.67TC6 (Ln = rare earth elements; T = Mn, Fe, Ru) and Eu3,16NiC6

1996 ◽  
Vol 51 (2) ◽  
pp. 249-256 ◽  
Author(s):  
Anne M. Witte ◽  
Wolfgang Jeitschko
Keyword(s):  
Crystal Structure ◽  
Magnetic Susceptibility ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Single Crystal ◽  
Crystal Structures ◽  
Variable Parameters ◽  
X Ray ◽  
Arc Melting ◽  
Structure Factors

Abstract The 14 carbides Ln3.67MnC6 (Ln = La-Nd) and Ln3.67TC6 (Ln = La-Nd, Sm; T = Fe, Ru) were prepared from the elemental components by arc-melting and subsequent annealing. Eu3.16NiC6 was obtained from a lithium flux. The crystal structures of these nearly isotypic, hexagonal compounds (P63/m, Z = 2) were determined from single-crystal X-ray data; La3.67- FeC6: a = 878.7(2), c = 535.1(1) pm, R = 0.052 for 548 structure factors and 25 variable parameters; Eu3.16NiC6: a -860.0(1), c = 548.2(2) pm, R = 0.015 for 606 structure factors and 25 variables. The structures differ from the previously reported Gd3Mn2C6 structure by the occupancy of one manganese position by rare earth atoms. Since the lanthanum atoms are larger than the manganese atoms, only two thirds of these manganese positions can be occupied by the lanthanum atoms in La3.67FeC6. Eu3.16NiC6 has similar atomic positions. The C-C bond distances in the C2 pairs are 130(2) and 126.5(5) pm in the La and Eu compounds, respectively. Magnetic susceptibility measurements with a SQUID magnetometer indicate La3.67FeC6 to be Pauli paramagnetic. A test for superconductivity was negative down to 3 K.

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