scholarly journals High temperature hydrothermal synthesis of rare-earth titanates: synthesis and structure of RE5Ti4O15(OH) (RE = La, Er), Sm3TiO5(OH)3, RE5Ti2O11(OH) (RE = Tm–Lu) and Ce2Ti4O11

2018 ◽  
Vol 47 (19) ◽  
pp. 6754-6762 ◽  
Author(s):  
Kyle Fulle ◽  
Liurukara D. Sanjeewa ◽  
Colin D. McMillen ◽  
Joseph W. Kolis
Keyword(s):  
Rare Earth ◽  
High Temperature ◽  
Hydrothermal Synthesis ◽  
Rare Earth Oxides ◽  
Hydrothermal Fluids

Reactions of rare-earth oxides with TiO2 were performed in high temperature (650–700 °C) hydrothermal fluids.

scholarly journals Design, Fabrication, and Characterization of New Materials Based on Zirconia Doped with Mixed Rare Earth Oxides: Review and First Experimental Results

Metals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 746 ◽  
Author(s):  
Adrian Mihail Motoc ◽  
Sorina Valsan ◽  
Anca Elena Slobozeanu ◽  
Mircea Corban ◽  
Daniele Valerini ◽  
...  
Keyword(s):  
Rare Earth ◽  
High Temperature ◽  
Extreme Environments ◽  
Chemical Properties ◽  
Electronic Configuration ◽  
Electron Beam Evaporation ◽  
Rare Earth Oxides ◽  
Added Value ◽  
High Price ◽  
Preliminary Results

Monazite is one of the most valuable natural resources for rare earth oxides (REOs) used as dopants with high added value in ceramic materials for extreme environments applications. The complexity of the separation process in individual REOs, due to their similar electronic configuration and physical–chemical properties, is reflected in products with high price and high environmental footprint. During last years, there was an increasing interest for using different mixtures of REOs as dopants for high temperature ceramics, in particular for ZrO2-based thermal barrier coatings (TBCs) used in aeronautics and energy co-generation. The use of mixed REOs may increase the working temperature of the TBCs due to the formation of tetragonal and cubic solid solutions with higher melting temperatures, avoiding grain size coarsening due to interface segregation, enhancing its ionic conductivity and sinterability. The thermal stability of the coatings may be further improved by using rare earth zirconates with perovskite or pyrochlore structures having no phase transitions before melting. Within this research framework, firstly we present a review analysis about results reported in the literature so far about the use of ZrO2 ceramics doped with mixed REOs for high temperature applications. Then, preliminary results about TBCs fabricated by electron beam evaporation starting from mixed REOs simulating the real composition as occurring in monazite source minerals are reported. This novel recipe for ZrO2-based TBCs, if optimized, may lead to better materials with lower costs and lower environmental impact, as a result of the elimination of REOs extraction and separation in individual lanthanides. Preliminary results on the compositional, microstructure, morphological, and thermal properties of the tested materials are reported.

Hydrothermal synthesis of LnMnO3 (Ln = Ho–Lu and Y): exploiting amphoterism in late rare-earth oxides

2009 ◽  
Vol 19 (25) ◽  
pp. 4375 ◽  
Author(s):  
Evan S. Stampler ◽  
William C. Sheets ◽  
Wilfrid Prellier ◽  
Tobin J. Marks ◽  
Kenneth R. Poeppelmeier
Keyword(s):  
Rare Earth ◽  
Hydrothermal Synthesis ◽  
Rare Earth Oxides

Ein Beitrag zur Kristallchemie dreiwertiger Seltenerdoxide Zur Stabilisierung der monoklinen B-Form / About the Crystal Chemistry of Three-Valent Rare Earth Oxides The Stabilisation of the Monoclinic B-Modification

1977 ◽  
Vol 32 (5) ◽  
pp. 495-498 ◽  
Author(s):  
W. Muschick ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Crystal Structure ◽  
Rare Earth ◽  
High Temperature ◽  
Single Crystals ◽  
Rare Earth Oxides ◽  
Temperature Reaction ◽  
Crystal Data ◽  
X Ray ◽  
High Temperature Reaction ◽  
Type Crystal

Single crystals of 1—x Ho2O3 : xCaO (x = 0.07), CaHoO2.5 (A) and Ca0.5Ho1.5O2.75 (B) were prepared by high temperature reaction and investigated with X-ray single crystal data. It can be shown that small amounts of CaO stabilize the monoclinic B-Typ of rare earth oxides. Phase (A) and (B) cannot be seen as a stabilized B-type crystal because they have an new crystal structure with space groupC22h–P 21/m, a = 656.6, b = 356.7, c = 529.4 pm, β = 92.3°; a = 650.2, b = 352.4, c = 584.5, β = 92.3°.

Effects of Rare Earth Oxides on Microstructures and Properties of Magnesia Refractories

2008 ◽  
Vol 368-372 ◽  
pp. 1158-1160 ◽  
Author(s):  
Bao Guo Zhang ◽  
Zhou Fu Wang ◽  
Shao Wei Zhang ◽  
Xi Tang Wang ◽  
Zi Wei Xu
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Rare Earth ◽  
High Temperature ◽  
Mechanical Strength ◽  
Grain Boundaries ◽  
Bulk Density ◽  
Rare Earth Oxide ◽  
Rare Earth Oxides ◽  
Microstructure And Mechanical Properties

The effects of Y2O3, La2O3 and Nd2O3 on the sintering, microstructure and mechanical properties of magnesia refractories were investigated. Addition of rare earth oxide (ReO) to magnesia refractories increases the bulk density, decreases the porosity and improves the mechanical strength of the refractories. The improved sinterability was attributable to the vacancies generation associated with the solid-solution reactions between MgO and ReO. In the samples with ReO, rare earth silicate phases form at magnesia grain boundaries, providing additional bonding between magnesia grains and between magnesia grains and matrix. Consequently, the samples with ReO showed much higher high temperature strengths than those without ReO.

scholarly journals Hydrothermal Synthesis of Ln(OH)3Nanorods and the Conversion to Ln2O3(Ln = Eu, Nd, Dy) Nanorods via Annealing Process

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Yanhua Zhu ◽  
Xiang Zhai ◽  
Lingling Wang
Keyword(s):  
Optical Properties ◽  
Rare Earth ◽  
Hydrothermal Synthesis ◽  
Physicochemical Properties ◽  
Hydrothermal Method ◽  
Rare Earth Oxides ◽  
Annealing Process ◽  
One Dimensional ◽  
Potential Applications ◽  
Xrd And Tem

One-dimensional rare earth oxides and hydroxides are of importance in many applications due to their rich physicochemical properties. In this work, we synthesized Ln(OH)3(Ln = Eu, Nd, Dy) nanorods by a hydrothermal method with the assistance of n-butylamine as an alkaline resource. The porous Ln2O3nanorods were produced through annealing the corresponding Ln(OH)3nanorods. XRD and TEM techniques were employed to characterize the products. The annealing process and the optical properties of as-synthesized Ln2O3are also investigated by TG and PL test. We expected that these nanomaterials could find potential applications in the future.

High-Temperature Jet Spray Reactor for the Preparation of Rare Earth Oxides by Pyrolysis: Computer Simulation

JOM ◽  
2014 ◽  
Vol 66 (9) ◽  
pp. 1647-1653 ◽  
Author(s):  
Qiu-yue Zhao ◽  
Chao Lv ◽  
Zi-mu Zhang ◽  
Zhi-he Dou ◽  
Ting-an Zhang ◽  
...  
Keyword(s):  
Computer Simulation ◽  
Rare Earth ◽  
High Temperature ◽  
Rare Earth Oxides
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