Rare-earth indium selenides RE3InSe6 (RE = La−Nd, Sm, Gd, Tb): Structural evolution from tetrahedral to octahedral sites

Decreasing thermal diffusivity of YSZ can increase the thermal barrier effect. Thermal diffusivity is in direct proportion to lattice oscillation amplitude and frequency. The addition of rare earth oxide into YSZ may induce the lattice distortion, which will result in the change of lattice oscillation frequency. In the present work, combined with the experiment, a theoretical study was proposed to investigate the effect of the rare earth elements on the thermal barrier effect of YSZ using first-principal calculations implemented CASTEP program. It has been found that the addition of the rear earth element can make larger lattice distortion and favorable to reduce the thermal conductivity. The calculation results are in agreement with our experimental results.

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Structural evolution of heavy rare Earth-based metal glass under high pressure

Journal of Physics Condensed Matter ◽

10.1088/1361-648x/abbea4 ◽

2020 ◽

Vol 33 (3) ◽

pp. 035405

Author(s):

Wang Yongyong ◽

Zhang Panpan ◽

Li Qing ◽

Li Gong

Keyword(s):

High Pressure ◽

Rare Earth ◽

Structural Evolution ◽

Heavy Rare Earth

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Effect of RE3+ on Structural Evolution of Rare-Earth Carbonates Synthesized by Facile Hydrothermal Treatment

Advances in Materials Science and Engineering ◽

10.1155/2019/1241056 ◽

2019 ◽

Vol 2019 ◽

pp. 1-10 ◽

Cited By ~ 1

Author(s):

Luca Spiridigliozzi ◽

Grazia Accardo ◽

Domenico Frattini ◽

Antonello Marocco ◽

Serena Esposito ◽

...

Keyword(s):

Rare Earth ◽

Hydrothermal Treatment ◽

Ammonium Carbonate ◽

Structural Evolution ◽

Structural Modifications ◽

Oxide Powders ◽

Earth Cation ◽

Diluted Solution ◽

Hydrothermal Transformation ◽

Biphasic Systems

In this work, nanoparticles of cerium hydroxycarbonates were synthesized by a facile hydrothermal treatment at 120°C with ammonium carbonate as the precipitating/mineralizer agent in diluted solution. The as-formed amorphous coprecipitate undergoes several morphological and structural modifications as a function of the duration of the hydrothermal treatment, leading after 8 h to the formation of monosized nanoparticles of hexagonal CeCO3OH. A similar behavior has been found when neodymium-based precursors are used as well, whereas the same treatment produces very different results by using different lanthanides-based precursors in terms of formed phases and morphologies, thus leading to the formation of pure tengerite-type structure phases, biphasic systems (tengerite type and hexagonal), or even entirely amorphous systems. Furthermore, the hydrothermal transformation is influenced by the redox behavior of the rare-earth cation (i.e., cerium) too, eventually resulting in the formation of fluorite-like structures. Therefore, a specific pathway of Ce(III) precursor transformations during hydrothermal treatment is proposed in this paper. Definitely, our results show that ammonium carbonate can be used as the precipitating/mineralizer agent to obtain cerium, doped-cerium, and neodymium hydroxycarbonates, which show excellent morphologies (i.e., characterized by spherical, nanosized particles with monomodal size distribution). Therefore, they can be used as optimal precursors for oxide powders. Conversely, when tengerite-type carbonate precursors are formed, their morphology is characterized by large and acicular particles.

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Faraday Rotation Spectra Analysis on TbYbBiIG Crystals in Optical Communication Band

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.562-564.1753 ◽

2012 ◽

Vol 562-564 ◽

pp. 1753-1756

Author(s):

Min Huang

Keyword(s):

Rare Earth ◽

Molecular Orbital ◽

Faraday Rotation ◽

Optical Communication ◽

Octahedral Site ◽

Rare Earth Ions ◽

Spectra Analysis ◽

Octahedral Sites ◽

Iron Garnet

his paper is concerned with the FR spectra analysis on the Bi, Tb and Yb partially substituted iron garnet crystals of Tb3-x-yYbyBixFe5O12. A specific FR (-1617o/cm at 1.55μm), a low FWC (0.009%/nm at 25oC) of Tb0.91Yb1.38Bi0.71Fe5O12 crystals grown from Bi2O3 self-fluxed melts can be used as broadband optical communication components. In order to interpret their FR spectra, a theory based on molecular-orbital levels of Fe3+ in tetrahedral and octahedral sites is used. It is shown that in the case of higher Bi3+ substitution, FR is mainly determined by the contribution of Fe3+ in the octahedral site. Furthermore, two types of rare-earth ions (Tb3+ and Yb3+) moderate the contribution to FR from Fe3+ in octahedral and decahedral sites and eventually have caused that Bi-substituted mixed rare-earth iron garnet has a near-zero Faraday rotation wavelength coefficient (FWC).

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Structural Evolution in the Rare-Earth Uranyl Vanadates Ln2[(UO2)2V2O8]3·nH2O, Singularity of the Lanthanum Compound, and Single-Crystal to Single-Crystal Partial Dehydration

Crystal Growth & Design ◽

10.1021/acs.cgd.9b00171 ◽

2019 ◽

Vol 19 (6) ◽

pp. 3305-3314 ◽

Cited By ~ 2

Author(s):

Alexandre Mer ◽

Saïd Obbade ◽

Philippe Devaux ◽

Francis Abraham

Keyword(s):

Rare Earth ◽

Single Crystal ◽

Structural Evolution ◽

Partial Dehydration ◽

The Rare Earth

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Structural Evolution in the RE(OAc)3 · 2AcOH Structure Type. A Non-Linear, One-Dimensional Coordination Polymer with Unequal Interatomic Rare Earth Distances

Crystals ◽

10.3390/cryst11070768 ◽

2021 ◽

Vol 11 (7) ◽

pp. 768

Author(s):

Markus Haase ◽

Philipp Rissiek ◽

Marianne Gather-Steckhan ◽

Felix Henkel ◽

Hans Reuter

Keyword(s):

Acetic Acid ◽

Rare Earth ◽

Coordination Polymer ◽

Structural Parameters ◽

Linear Regression Analysis ◽

Structural Evolution ◽

Structure Type ◽

One Dimensional ◽

Coordination Modes ◽

Non Linear

The existing range of the centrosymmetric, triclinic RE(OAc)3 · 2AcOH structure type has been extended for RE = Eu and Gd while the structure data of the Nd- and Sm-compounds have been revised and corrected, respectively, using low temperature (T = 100 K), well resolved (2θmax = 56°), highly redundant SCXRD data in order to evaluate the structural evolution within this class of acetic acid solvates by statistical methods. Within the nine-fold mono-capped square-antiprismatic coordination spheres of the RE3+ ions, RE-O distances decrease as a result of lanthanide contraction; some with different rates depending on the coordination modes (2.11/2.21) of the acetate ions. The experimental data show that the internal structural parameters of the acetate ions also correlate with their coordination modes. Both acetic acid molecules act as hydrogen bond donors but only one as monodentate ligand. The geometries of the hydrogen bonds reveal that they are strongly influenced by the size of the rare earth atom. The non-linear, one-dimensional coordination polymer propagates with unequal RE···RE distances along the a-axis. Rods of the coordination polymer are arranged in layers congruently stacked above each other with the hydrogen bonded acetic acid molecules as filler in between. In most cases, data fitting is best described in terms of a quadratic rather than a linear regression analysis.

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Structural and Solid State Chemistry of Mixed Valence Oxides

MRS Proceedings ◽

10.1557/proc-156-25 ◽

1989 ◽

Vol 156 ◽

Cited By ~ 2

Author(s):

Galy Jean

Keyword(s):

Rare Earth ◽

Solid State ◽

Mixed Valence ◽

Structural Evolution ◽

Oxygen Adsorption ◽

Double Layers ◽

Solid State Chemistry ◽

Copper Coordination ◽

Intergrowth Structures ◽

Rare Earth Substitution

ABSTRACTThe structural evolution versus oxygen adsorption ↔ desorption of the LnBa2Cu3O6+x series, the influence of rare-earth substitution on oxygen network and copper coordination (CN = 2, 4, 4 + 1, 5) in Bi2Sr2Ca1−yLnyCu2O8 series (Ln = La, Yb; 0≤y≤1) are followed. Images of parent mixed valence oxides, i.e. vanadium bronzes, with their single or double layers structures versus intercalated ions with ideal intergrowth structures like the new Na0.70V2O5 oxybronze are presented. The ability to exhibit double non stoichiometry, i.e. LixV3O8−y (0≤y≤1) in the homologous series LixV3(1+n)O8+7n (0≤n≤∞) is explained.

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Microstrain-assisted polymorphic phase transitions in (Eu1−x La x )2O3

Journal of Applied Crystallography ◽

10.1107/s1600576718016989 ◽

2019 ◽

Vol 52 (1) ◽

pp. 32-39 ◽

Cited By ~ 2

Author(s):

K. A. Irshad ◽

A. Saikumaran ◽

V. Srihari ◽

S. Kalavathi ◽

N. V. Chandra Shekar

Keyword(s):

Rare Earth ◽

Phase Transitions ◽

Structural Parameters ◽

Structural Phase ◽

Structural Evolution ◽

Type Structure ◽

X Ray Diffraction ◽

The Difference ◽

Rare Earth Sesquioxides ◽

The Rare Earth

Solid solutions, (Eu1−x La x )2O3 (0 ≤ x ≤ 1), of the rare earth sesquioxides Eu2O3 and La2O3 have been prepared by a simple soft chemistry approach. The composition and morphology of the as-synthesized oxides have been characterized using energy-dispersive spectroscopy and scanning electron microscopy. The particles are of irregular shape and submicrometre size. In order to understand the structural evolution as a function of composition, angle-dispersive X-ray diffraction measurements have been carried out and the structural parameters have been obtained through Rietveld refinement. A structural phase transition from the cubic (C-type) to the monoclinic (B-type) structure and subsequently to the hexagonal (A-type) structure was observed with an increasing substitution of La. A detailed analysis of the transition boundaries in terms of the average cationic radius, R RE, shows that the onset of the C → B transition is at R RE = 0.980 Å, whereas the B → A transition occurs at R RE = 1.025 Å. A biphasic region of cubic and monoclinic structures is observed for 0.2 ≤ x ≤ 0.4 and one of monoclinic and hexagonal structures is observed for 0.5 ≤ x ≤ 0.6. The microstrain induced by the difference in size of the rare earth cations introduces a substitutional disorder in the crystal structure, which is a plausible cause of the observed phase transitions in these oxides.

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