Topical trends in the application of rare-earth metals and their compounds in the production of magnetic and luminescent materials

2020 ◽  
pp. 4-23
Author(s):  
V. B. Baranovskaya ◽  
Yu. A. Karpov ◽  
K. V. Petrova ◽  
N. A. Korotkova
Keyword(s):  
Rare Earth ◽  
Magnetic Materials ◽  
Rare Earth Metals ◽  
Cold Climate ◽  
Diagnostic Methods ◽  
Synthesis Methods ◽  
Luminescent Materials ◽  
Fluorescent Lamps ◽  
Current Trends ◽  
The Creation

This review is devoted to the review of current trends in the use of rare-earth metals (REM) in two major scientific and technical fields – the production of magnetic and luminescent materials. The reviews show that it is REM that gives this product unique properties. The information on the content of matrix and alloying components, their influence on achieving the required characteristics of the most popular magnetic materials is systematized. The prospects of new combinations of rare-earth metals in the further progress of the production of magnetic materials for various purposes are shown. Along with the traditional cobalt-samarium and neodymium-iron-boron compositions, new magnetic materials with increased hysteresis properties and temperature-time stability have been developed, phases with variable valence have been synthesized, which are used as memory elements in information systems. The article also reviews and summarizes the results of studies in another important area of REM application – the creation of luminescent materials. Phosphors based on compounds of rare earth metals are used in the production of high-pressure mercury lamps with improved characteristics, X-ray screens, high and low pressure fluorescent lamps, screens for electron-optical converters. Narrow-band phosphors based on REM compounds are of interest for lamps used in plant growing, especially for areas with a cold climate, where year-round plant growth is possible only with the use of additional radiation sources.The trends in the synthesis of luminescent materials using various rare-earth metals and their combinations are revealed. Attention is turned to the need to use chemically pure precursors of rare-earth metals in the creation of such materials. The prospects of creating nanophosphors, as well as the improvement of synthesis methods and diagnostic methods, are noted.

POSSIBLE EVIDENCE FOR A VALENCE BAND SATELLITE IN PHOTOEMISSION SPECTRA FROM Sc(0001)

1994 ◽  
Vol 01 (04) ◽  
pp. 649-653 ◽  
Author(s):  
A.J. PATCHETT ◽  
S.S. DHESI ◽  
R.I.R. BLYTH ◽  
S.D. BARRETT
Keyword(s):  
Electronic Structure ◽  
Rare Earth ◽  
Binding Energy ◽  
Single Crystals ◽  
Valence Band ◽  
Ground State ◽  
Rare Earth Metals ◽  
Final State ◽  
Bulk Single Crystals ◽  
The Creation

An intense photoemission feature is observed at a binding energy of ~10 eV in the UV photoemission spectra from the (0001) surfaces of bulk single crystals of rare-earth metals. This emission cannot be explained in terms of ground state electronic structure and we have been unable to attribute its existence to the presence of contamination of the surface. We present some evidence that may indicate its origin lies in the creation, by the photoemission process, of a metastable two-hole final state.

Leaching of Rare Earth Metals from Phosphor Coating of Waste Fluorescent Lamps

2018 ◽  
Vol 72 (3) ◽  
pp. 623-634 ◽  
Author(s):  
Amit Anand ◽  
Randhir Singh ◽  
Abdul Rauf Sheik ◽  
Malay Kumar Ghosh ◽  
Kali Sanjay
Keyword(s):  
Rare Earth ◽  
Rare Earth Metals ◽  
Fluorescent Lamps ◽  
Phosphor Coating

ZnS nanocrystals co-activated by transition metals and rare-earth metals—a new class of luminescent materials

2001 ◽  
Vol 93 (2) ◽  
pp. 101-105 ◽  
Author(s):  
Ping Yang ◽  
Mengkai Lü ◽  
Dong Xü ◽  
Duolong Yuan ◽  
Guangjun Zhou
Keyword(s):  
Rare Earth ◽  
Transition Metals ◽  
Rare Earth Metals ◽  
Luminescent Materials ◽  
New Class ◽  
Zns Nanocrystals

Secondary Resources of Rare Еarth Мetals

2020 ◽  
Vol 24 (9) ◽  
pp. 44-50
Author(s):  
S.A. Chernyi
Keyword(s):  
Rare Earth ◽  
Rare Earths ◽  
Industrial Waste ◽  
Rare Earth Metals ◽  
Nickel Metal ◽  
Nickel Metal Hydride ◽  
Processing Technologies ◽  
Apatite Concentrate ◽  
Fluorescent Lamps ◽  
High Processing

The article provides an overview of the main existing methods for recycling rare earth metals from various types of waste. It was noted that the demand for rare-earth metals is increasing annually due to the growth of advanced technologies, mainly in the sectors of electronics, power engineering and photonics. It has been established that in countries producing final products of high processing, the chemical-technological processes of processing goods that have worked out their life cycle, and, first of all, fluorescent lamps, NdFeB magnets from electronic devices, and nickel-metal hydride (NiMeH) batteries containing rare earths are most quickly created. The most profitable and recycling option is the reuse of products containing rare-earth metals, however, such technologies are applicable for a narrow range of waste. Another important area of REM recycling is the processing of industrial waste. For countries with developed mining and chemical industries, mining processing technologies are attractive. It is shown that for Russia, more appropriate are schemes for the disposal of industrial waste, primarily waste from the production of apatite concentrate. The main problems of the development of REM recycling are identified: low content and dispersion of rare earths in waste; the presence of impurities that impede the extraction of valuable components and the toxicity of the used recycling schemes.

Development of nanostructured magnetic materials based on high-purity rare-earth metals and study of their fundamental characteristics

2014 ◽  
Vol 56 (9) ◽  
pp. 1778-1784 ◽  
Author(s):  
I. A. Pelevin ◽  
I. S. Tereshina ◽  
G. S. Burkhanov ◽  
S. V. Dobatkin ◽  
T. P. Kaminskaya ◽  
...  
Keyword(s):  
Rare Earth ◽  
Magnetic Materials ◽  
High Purity ◽  
Rare Earth Metals

scholarly journals An Overview of Rare Earth Ores Beneficiation in Vietnam

2021 ◽  
Vol 1 (2) ◽  
Author(s):  
Thi Kim Dung NHU ◽  
Van Luan PHAM ◽  
Thi Chinh VU ◽  
Van Duoc TRAN
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Magnetic Materials ◽  
Animal Feed ◽  
Rare Earth Metals ◽  
Earth’S Crust ◽  
Research Projects ◽  
Essential Minerals ◽  
Different Types ◽  
Earth's Crust

Rare earth metals are used in electricity, electronics, nuclear, optics, space, metallurgy,superconducting and super magnetic materials, glass and ceramics, and agriculture. Some rare earthelements are added to fertilizers for crops and some trials for animal feed. Rare earth elements, exceptfor radioactive promethium, are relatively abundant in the earth's crust. Vietnam has a tremendous rareearth potential, distributed mainly in the Northwest, including Nam Xe, Dong Pao, Muong Hum, andYen Bai. There are many research projects on rare earth ores of different types globally, but the focus ismainly on the essential minerals, including monazite, xenotime, and bastnaesite. This report summarizesresearch data on rare earth ore intending to produce a general assessment of rare earth ore and itsbeneficiation technology in Vietnam.

scholarly journals Processes and Technologies for the Recycling of Spent Fluorescent Lamps

2014 ◽  
Vol 16 (3) ◽  
pp. 80-85 ◽  
Author(s):  
Wojciech Kujawski ◽  
Beata Pospiech
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Industrial Application ◽  
New Technologies ◽  
Rare Earth Metals ◽  
Fluorescent Lamps ◽  
Potential Source ◽  
Efficient Recovery

Abstract The growing industrial application of rare earth metals led to great interest in the new technologies for the recycling and recovery of REEs from diverse sources. This work reviews the various methods for the recycling of spent fluorescent lamps. The spent fluorescent lamps are potential source of important rare earth elements (REEs) such as: yttrium, terbium, europium, lanthanum and cerium. The characteristics of REEs properties and construction of typical fl uorescent lamps is described. The work compares also current technologies which can be utilized for an efficient recovery of REEs from phosphors powders coming from spent fluorescent lamps. The work is especially focused on the hydrometallurgical and pyrometallurgical processes. It was concluded that hydrometallurgical processes are especially useful for the recovery of REEs from spent fluorescent lamps. Moreover, the methods used for recycling of REEs are identical or very similar to those utilized for the raw ores processing.

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