scholarly journals High-purity core-shell α″-Fe16N2/Al2O3 nanoparticles synthesized from α-hematite for rare-earth-free magnet applications

2016 ◽  
Vol 27 (6) ◽  
pp. 2520-2525 ◽  
Author(s):  
Takashi Ogi ◽  
Qing Li ◽  
Shinji Horie ◽  
Akito Tameka ◽  
Toru Iwaki ◽  
...  
Keyword(s):  
Rare Earth ◽  
High Purity ◽  
Core Shell ◽  
Al2o3 Nanoparticles

scholarly journals Magnetic and Electronic Properties of Heavy Lanthanides (Gd, Tb, Dy, Er, Ho, Tm)

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 82
Author(s):  
Radel R. Gimaev ◽  
Aleksei S. Komlev ◽  
Andrei S. Davydov ◽  
Boris B. Kovalev ◽  
Vladimir I. Zverev
Keyword(s):  
Rare Earth ◽  
Electronic Properties ◽  
High Purity ◽  
Materials Science ◽  
Rapid Development ◽  
Rare Earth Metals ◽  
State University ◽  
Important Place ◽  
Heavy Lanthanides ◽  
Baikov Institute

Rare earth metals (REM) occupy a special and important place in our lives. This became especially noticeable during the rapid development of industry in the industrial era of the twentieth century. The tendency of development of the rare-earth metals market certainly remains in the XXI century. According to experts estimates the industry demand for chemical compounds based on them will tend to grow during the nearest years until it reaches the market balance. At the same time, the practical use of high-purity rare-earth metals requires the most accurate understanding of the physical properties of metals, especially magnetic ones. Despite a certain decline in interest in the study of high-purity REM single crystals during the last decade, a number of scientific groups (Ames Lab, Lomonosov Moscow State University (MSU), Baikov Institute of Metallurgy and Materials Science Russian Academy of Science (RAS)) are still conducting high-purity studies on high-purity metal samples. The present article is a combination of a review work covering the analysis of the main works devoted to the study of heavy REMs from gadolinium to thulium, as well as original results obtained at MSU. The paper considers the electronic properties of metals in terms of calculating the density of states, analyzes the regularities of the magnetic phase diagrams of metals, gives the original dependences of the Neel temperature and tricritical temperatures for Gd, Tb, Dy, Er, Ho, Tm, and also introduces a phenomenological parameter that would serve as an indicator of the phase transformation in heavy REMs.

Synthesis of Lanthanum Oxide Using Hydrogen Peroxide as Auxiliary Reagent by Spray Pyrolysis Method

2014 ◽  
Vol 1081 ◽  
pp. 38-42
Author(s):  
Zhen Feng Wang ◽  
Wen Yuan Wu ◽  
Xue Bian ◽  
Shou Feng Xue
Keyword(s):  
Hydrogen Peroxide ◽  
Rare Earth ◽  
Spray Pyrolysis ◽  
Reaction Temperature ◽  
High Purity ◽  
Chloride Solution ◽  
Lanthanum Oxide ◽  
Lanthanum Chloride ◽  
Spray Pyrolysis Method ◽  
The Rare Earth

With lanthanum chloride solution as raw material, and use the hydrogen peroxide of clean and pollution-freeobtained from oxidation reaction as auxiliary reagent, and with the carrier gas together form spray pyrolysis to obtain lanthanum oxide. On the one hand, in the hydrogen peroxide system, the temperature of direct pyrolysis reaction of lanthanum chloride solution decreased obviously, The reaction temperature is decreased from 1280°C to 1000°C or less. That reduce the energy consumption and simplify the requirements of pyrolysis equipment technology. The production process does not use NH3.H2O and NaOH to precipitate. It does not produce the traditional process of NH4+, Na+ to pollute water. It can greatly reduce the damage to the environment, and can product with high yield, high purity of the rare earth oxide. This method not only applies to the pyrolysis of the rare earth chloride solution, also applies to metal chloride solution, such as FeCl3, AlCl3, NiCl2. It was shown that the reaction temperature has been effectively reduced, VLaCl3: VH2O2 with 1: 1.5 can get high purity of La2O3.

Synthesis and characterization of upconversion nanoparticles with shell structure and ligand-free hydrophilic modification

RSC Advances ◽  
2015 ◽  
Vol 5 (101) ◽  
pp. 83149-83154 ◽  
Author(s):  
Di Kang ◽  
Xiaoyan Song ◽  
Jinfeng Xing
Keyword(s):  
Rare Earth ◽  
Shell Structure ◽  
Synthesis And Characterization ◽  
Upconversion Nanoparticles ◽  
Core Shell ◽  
Hydrophilic Modification ◽  
Ligand Free ◽  
Core Shell Structure

Rare-earth upconversion nanoparticles (UCNPs) with α and β phases were prepared. UCNPs with core–shell structure were prepared and modified to be hydrophilic by ligand-free hydrophilic modification.

scholarly journals Research Progress in Preparation and Purification of Rare Earth Metals

Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1376
Author(s):  
Hang Liu ◽  
Yao Zhang ◽  
Yikun Luan ◽  
Huimin Yu ◽  
Dianzhong Li
Keyword(s):  
Rare Earth ◽  
High Purity ◽  
Rare Earth Metals ◽  
Melting Zone ◽  
Thermal Reduction ◽  
Zone Melting ◽  
Research Progress ◽  
Molten Salt Electrolysis ◽  
Interstitial Impurities ◽  
Metallic Impurities

The purity of rare earth metals is one of the most important factors to research and develop high technique materials. However, high purity rare earth metals are not easily achieved. This review summarizes the preparation and purification methods of rare earth metals. First, the preparation principle and process of molten salt electrolysis and metal thermal reduction are introduced. The main sources of metallic impurities and interstitial impurities in rare earth metals as well as the action mechanism of reducing the concentration of different impurities are analyzed and summarized. Then, the purification principle and process of vacuum distillation, arc melting, zone melting, and solid state electromigration are also discussed. Furthermore, the removal effect and function rule of metallic impurities and interstitial impurities in rare earth metals are outlined. Finally, the crucial issues in the development of high purity rare earth metals are put forward, and the development direction of high purity rare earth metals in future are pointed out on this basis.

scholarly journals Strongly Exchange Coupled Core|Shell Nanoparticles with High Magnetic Anisotropy: A Strategy toward Rare-Earth-Free Permanent Magnets

2016 ◽  
Vol 28 (12) ◽  
pp. 4214-4222 ◽  
Author(s):  
E. Lottini ◽  
A. López-Ortega ◽  
G. Bertoni ◽  
S. Turner ◽  
M. Meledina ◽  
...  
Keyword(s):  
Rare Earth ◽  
Magnetic Anisotropy ◽  
Permanent Magnets ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Core Shell Nanoparticles
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