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

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.

Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1376
Author(s):  
Hang Liu ◽  
Yao Zhang ◽  
Yikun Luan ◽  
Huimin Yu ◽  
Dianzhong Li

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.


2014 ◽  
Vol 56 (9) ◽  
pp. 1778-1784 ◽  
Author(s):  
I. A. Pelevin ◽  
I. S. Tereshina ◽  
G. S. Burkhanov ◽  
S. V. Dobatkin ◽  
T. P. Kaminskaya ◽  
...  

1991 ◽  
Vol 30 ◽  
pp. 61-72 ◽  
Author(s):  
P.N. Mohan Das ◽  
A.D. Damodaran ◽  
M. Subhash

1991 ◽  
Vol 62-64 ◽  
pp. 637-638
Author(s):  
Gennady S. Burkhanov ◽  
L.A. Boyarsky ◽  
O.D. Chistayakov ◽  
N.B. Kolchugina

2021 ◽  
Author(s):  
Mohamed Gamal Mahmoud ◽  
Yasser Zedan ◽  
Agnes-Marie Samuel ◽  
Victor Songmene ◽  
Herebert W. Doty ◽  
...  

The present article reviews a large number of research publications on the effect of mischmetal (MM), rare earth metals (RE), La or Ce, and combinations of La + Ce on the performance of Al-Si cast alloys mainly 319, 356, 380, 413, and 390 alloys. Most of these articles focused on the use of rare earth metals as a substitute for strontium (Sr) as a eutectic silicon (Si) modifier if added in low percentage (< 1 wt.%) to avoid precipitation of a significant amount of insoluble intermetallics and hence poor mechanical properties. Other points that were considered were the affinity of RE to react with Sr., reducing its effectiveness as modifier, as well as the grain refining efficiency of the added RE in any form. None of these articles mentioned the exact composition of the RE used and percentage of tramp elements inherited from the parent ore. Using high purity La or Ce proved to have no effect on the Si shape, size or distribution, in particular at low solidification rates (thick sections). However, regardless the source of the RE, its addition to Sr-modified alloys reduced the modification effect. As for grain refining, apparently a high percentage of RE (> 1 wt.%) is required to achieve a noticeable reduction in grain size, however at the cost of alloy brittleness.


Author(s):  
T.K. Jumadilov ◽  
◽  
Kh. Khimersen ◽  
B. Totkhuskyzy ◽  
J. Haponiuk ◽  
...  

Rare earth elements play an important role in the production, energy, and high technology. Due to the rapid development of industry, the demand for rare earth metals is rising every day. Therefore, it is necessary to improve the extraction of rare earth metals from various sources to meet the demand for these elements. Currently, pyro- and hydrometallurgical technologies are used to extract rare earth metals from an ore and other secondary sources (industrial wastewater, acid drainage mines, etc.). Hydrometallurgical technologies include precipitation, extraction, adsorption, and ion exchange methods. Adsorption is one of the most effective methods for the extraction and separation of rare earth elements. Adsorption methods are highly selectivity to metal ions and have low emissions. However, not all adsorbents are effective in producing the same metal ions. This study provides an overview of the different adsorbents that can be used to extract rare earth elements from aquatic systems. Hydrogels and molecular polymers have been found to be cost-effective methods for high-grade rare earth metals. Further research is needed to ensure the performance of these systems.


2016 ◽  
Vol 45 (11) ◽  
pp. 2793-2797 ◽  
Author(s):  
Zhang Xiaowei ◽  
Wang Zhiqiang ◽  
Chen Dehong ◽  
Li Zongan ◽  
Miao Ruiying ◽  
...  

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