قائمة الطعام
A new series of rare-earth-cerate high-entropy ceramics with compositions of (La 0.2 Nd 0.2 Sm 0.2 Gd 0.2 Dy 0.2) 2 Ce 2 O 7 (HEC1), ...
New data on rare earth element (REE) concentrations and distribution patterns of columbite-tantalite minerals from Ta-ore provinces worldwide are presented.The REE geochemistry was studied by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Five major types of chondrite-normalized REE distribution …
Rare-earth tantalates, with high density and monoclinic structure, and niobates with monoclinic structure have been paid great attention as potential optical materials. In the last decade, we focused on the crystal growth technology of rare-earth tantalates and niobates and studied their luminescence and physical properties. A series of rare-earth …
High‐entropy ferroelastic rare‐earth tantalite ceramic: (Y0.2Ce0.2Sm0.2Gd0.2Dy0.2)TaO4. Article. May 2021; Wang Jun; ... The rare earth bismuth tungstates with composition BiLnWO6 (Ln=rare ...
Seven kinds of high-entropy rare-earth tantalates were synthesized by solid phase sintering and high throughput experiments. • The influence of lattice distortion effect in 5RETaO 4 on thermal conductivity was revealed.. HE-ND ceramics perform exceptionally well, with thermal conductivity of 1.43 W m −1 K −1 (800 °C) and TEC of 10.3 × 10 −6 K …
Experimental investigation of Ta 2 O 5 solubility. Experimental data on the solubility of Ta 2 O 5 as a function of the total concentrations of HF, KF, NaF, and LiF are shown in Fig. 1 and Table 1, including runs with different starting materials and compositions.The data show similarities in Ta 2 O 5 solubility in fluoride solutions over a …
This perspective outlines the research directions of ferroelastic rare-earth (RE) tantalates (RETaO 4), which have been studied as multifunctional thermal/environmental barrier coatings (T/EBCs) with working temperatures above 1600°C.Ferroelastic RETaO 4 ceramics exhibit several distinct features, including the …
The Kenticha rare-element pegmatite, a globally important tantalite source in the Neoproterozoic Adola Belt of southern Ethiopia, is a highly fractionated, huge (2,000 m long and up to 100 m thick), subhorizontal, sheet-like body, discordantly emplaced in ultramafic host rock. It corresponds to the spodumene subtype of the rare-element …
Wang, J., Wu, F., Zou, R., Wu, Y., Gan, M., Feng, J., & Chong, X. (2021). High‐entropy ferroelastic rare‐earth tantalite ceramic: (Y 0.2 Ce 0.2 Sm 0.2 Gd 0.2 Dy 0 ...
Emerging of high-entropy ceramics has brought new opportunities for designing and optimizing materials with desired properties. In the present work, high-entropy rare-earth zirconates (La 0.2 Nd 0.2 Sm 0.2 Eu 0.2 Gd 0.2) 2 Zr 2 O 7 and (Yb 0.2 Nd 0.2 Sm 0.2 Eu 0.2 Gd 0.2) 2 Zr 2 O 7 are designed and synthesized. Both high …
ceramic. A type of rare-earth tantalite ceramic NdTaO 4 was synthesized by the solid-state reaction method and investigated for the relationship between the …
A rare earth mining project in Madagascar that has been in turmoil for the last two years took another blow in September, when its concession, previously valued at over $1 billion, was reappraised ...
High‐entropy ferroelastic rare‐earth tantalite ceramic: (Y 0.2 Ce 0.2 Sm 0.2 Gd 0.2 Dy 0.2 )TaO 4 | Semantic Scholar. DOI: 10.1111/JACE.17932. Corpus ID: …
The rare earth mineral industry in Sierra Leone is touted as a new frontier with ongoing exploration and exploitation of "new deposits". However, a review of Sierra Leone's historical mining development reveals not only that knowledge of the occurrence of rare earth mineral deposits date back to the early 20th century when the British colonial …
A type of rare-earth tantalite ceramic NdTaO4 was synthesized by the solid-state reaction method and investigated for the relationship between the structure and microwave dielectric properties for ...
HEC studies have suggested that the thermal conductivity of high-entropy rare-earth tantalate can be further reduced by doping multiple rare earth elements into …
Alkali metal and rare earth element evolution of rock-forming minerals from the Gatumba area pegmatites (Rwanda): quantitative assessment of crystal-melt fractionation in the regional zonation of pegmatite groups ... The No. 31 vein is identified as pegmatite by CMS features. New U–Pb dating CGMs (columbite-tantalite group …
DOI: 10.1016/j.ceramint.2022.06.281 Corpus ID: 250235393; Bond characteristics and microwave dielectric ceramic of rare-earth tantalite NdTaO4 ceramic @article{Shi2022BondCA, title={Bond characteristics and microwave dielectric ceramic of rare-earth tantalite NdTaO4 ceramic}, author={Liang Shi and Xueying Wang and Rui …
A series of rare-earth-tantalate high-entropy ceramics ((5RE0.2)Ta3O9, where RE = five elements chosen from La, Ce, Nd, Sm, Eu and Gd) were prepared by conventional sintering in air at 1500 °C ...
Tantalum is sometimes, but only rarely, found uncombined in nature. It occurs mainly in the mineral columbite-tantalite, which also contains other metals including niobium. It is mined in many places including Australia, Canada and Brazil. ... Both are rare earth elements. Tantalum now sits below niobium in the periodic table. It has an atomic ...
The chondrite-normalized rare earth element (REE) patterns for the CGMs invariably show depleted light rare earth elements (LREEs), ... Tindle, A. G., and Breaks, F. W. (2000). Columbite–tantalite mineral chemistry from rare-element granitic pegmatites: Separation Lake area, N.W. Ontario, Canada. Mineral. Petrol. 70, 165–198. doi:10.1007 ...
The Ngualla Project is a world-class rare earth development located near the Ngwala Village and approximately 150km from the City of Mbeya in the Songwe Region and on the edge of the East African Rift Valley. The project entails the construction of a mine, mill, concentrator, community projects and associated infrastructure.
The Kolmozero rare metal (spodumene) deposit is situated in the south-eastern part of the Archean Kolmozero–Voronya (also referred to as –Voronja or –Voron'ya) greenstone belt in the Kola Peninsula (Fig. 1).The long tectonic history of this Archean suture zone (2930–2550 Ma; Pozhilenko et al., 2002) terminated in the formation of a …
The rare earth element (REE) patterns of the primary ore zone shows slight enrichment in LREE with strong negative Eu-anomaly. From mineralogical assemblage, tectonic setting and geochemical signatures the genesis of Kenticha tantalite deposit is by partial melting of metasedimentary rocks predated the granite and pegmatite with later ...
Rare Earths. High‐entropy ferroelastic rare‐earth tantalite ceramic: (Y0.2Ce0.2Sm0.2Gd0.2Dy0.2)TaO4. DOI: 10.1111/jace.17932. Authors: Wang Jun. …
High-entropy single-phase rare earth titanates (RE 0.2 Gd 0.2 Ho 0.2 Er 0.2 Yb 0.2) 2 Ti 2 O 7 (RE = Sm, Y, Lu) were designed and synthesized successfully, in which their lattice distortion was quantitatively described by mass disorder and size disorder. It is worth mentioning that (Y 0.2 Gd 0.2 Ho 0.2 Er 0.2 Yb 0.2) 2 Ti 2 O 7 could obtain the low …
Public data have been reviewed and analysed, and the portions of Ta produced from these above resources are 64%, 20%, and 16%, respectively [4,41]. 3.1 Ta minerals Tantalum is a rare metal, and its abundance in the …
In this study, high-entropy rare-earth tantalate ceramics (Y 0.2 Ce 0.2 Sm 0.2 Gd 0.2 Dy 0.2)TaO 4 ((5RE 0.2)TaO 4) have been successfully fabricated.The possibility of formation of (5RE 0.2)TaO 4 was verified via first-principles calculations. In addition, the phase structure, ferroelastic toughening mechanism, thermophysical, and …
Through tuning the rare-earth cations, an order–disorder transition occurs from certain partially ordered weberite structure (C222 1) to disordered defective fluorite structure (Fm 3 ¯ $bar{3}$ m).
High entropy rare earth titanate (Y 0.2 Gd 0.2 Ho 0.2 Er 0.2 Yb 0.2) 2 Ti 2 O 7 has a low thermal conductivity (1.51 W·m −1 ·K −1, 1500 ℃). However, the main …
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