The spectra of the mid-series rare-earths are very complex because of the high number of levels associated with the half-full 4f sub shell. The 3d 5/2 resonance lines are spread on a wide energy range while the 3d 3/2 resonance lines are located clearly towards the higher energies of the excitation emissions.
1. Introduction. Rare earth elements (REEs) are widely used in military, metallurgy, petrochemical, glass, ceramics, and agriculture to improve the quality and performance of various industrial materials (Cheisson and Schelter, 2019, Goodenough et al., 2018).Conventional mining processes to produce REEs involve acid precipitation …
Reisfeld, R. (1975) Radiative and nonradiative transition of rare earths in glasses, Structure and Bonding 22, 123–175; Reisfeld R., (1976) Excited states and energy transfer from donor cations to rare earths in the condensed phase, Structure and Bonding 30, 65–97. Article CAS Google Scholar
The spectra of the rare earths were photographed under controlled excitation so that either the spectra of the doubly or triply ionized elements are brought out with maximum intensity. A mild excitation is used in addition to give the first and second spectra for comparison. Some regularities are immediately apparent and vary very gradually ...
Because of the complexity of the spectra of the rare earths and the questionable purity of the samples, many claims were being made for new elements that proved false. Despite these difficulties, by 1901 only two rare earths were still undiscovered. In 1907, almost simultaneously, Georges Urbain in France, Carl Auer von …
Beyond rare earths. Nature Materials 23, 303 ( 2024) Cite this article. There is a good reason why the rare-earth elements are so called. When Carl Axel Arrhenius discovered the mineral ytterbite ...
Rare earths must be understood in light of their history and the beginnings of their extraction. ... They exhibit a discrete energy spectrum in the solid state (unlike semiconductors, for example). The reason for this is the special structure of their electron shells. Optical transitions take place within the 4f shell, which is shielded from ...
Rare earths, scandium, yttrium, and the fifteen lanthanoids from lanthanum to lutetium, are classified as critical metals because of their ubiquity in daily life. They are present in magnets in cars, especially electric cars; green electricity generating systems and computers; in steel manufacturing; in glass and light emission materials ...
For light-emitting diode (LED) applications, rare earth luminescent materials with high photoluminescence quantum yields, good stabilities, and broad luminescence spectra ranging from the visible ...
The Raman spectral curves of base and soda–lime–silicate glasses doped with different rare earth oxides (La 2 O 3, CeO 2, Nd 2 O 3, Gd 2 O 3 and Y 2 O 3) are illustrated in Fig. 1.It can be observed from Fig. 1 that the Raman spectra of the investigated glasses, in 120–1400 cm −1 region, have three main bands at around …
Anomalous Rare Earths and Actinides. Valence Fluctuation and Heavy Fermions. 1987, Pages 490-492. ... France We present a theoretical study of L n r X A S and XPS spectra in light rare-earth metallic compounds and within the Anderson impurity model. First we point out the relation between L i n -XAS spectrum and core-XPS …
Spectrum Metals Limited, formerly Spectrum Rare Earths Limited (Spectrum), is a resource development company, which focuses on the commercialization of mineral assets. The Company is engaged in the exploration and evaluation of rare earths. The Company holds approximately 156 square kilometers of prospective …
Spectra and energy transfer of rare earths in inorganic glasses. Part of the book series: Structure and Bonding ( (STRUCTURE,volume 13)) These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
The UV-vis absorption spectra of rare earth sulfides did not depend on the crystal structure of rare earth sulfides, but on the 4f electronic structure of rare earth element. ... Table 2 shows the optical band gaps of rare earths sulfides prepared via the sulfurization of commercial oxide powders. It can be seen that the optical band gaps of ...
Keywords: terbium complexes; bromo benzoic acid; steric effect; fluorescent spectrum; rare earths Weissman et al. [1] found that ultraviolet (UV) light could stimulate some rare earth complexes which have a conju- gated system with formation of organic compounds and can make it emit visible light. Since the 40s of the last century, …
In 1906, Becquerel observed a particularly sharp spectral line from an ore containing rare earth and transition-metal elements. At that time, rare earths were merely regarded as impurities in minerals, and received scant attention from scientists. After Bohr’s...
For many decades, the richness of rare-earth spectra have offered the tantalizing possibility of deriving local structure from spectra. Current developments in modeling and ab initio calculations are close making this dream a reality. ... K.A. Gschneidner Jr., L. Eyring (Eds.), Handbook on the Physics and Chemistry of the Rare …
The multiplets of energy levels for electronic states on each rare-earth ion create a rich spectrum of light emission, most of it in the visible range of the electromagnetic spectrum. Moreover, the large magnetic moments of some rare earths and their anisotropy—the moment's preferred direction in the crystal field—make the …
The rare earths (REs) are a family of 17 elements that exhibit pronounced chemical similarities as a group, while individually expressing distinctive and varied electronic properties. These atomistic electronic properties are extraordinarily useful and motivate the application of REs in many technologies and devices.
When mining restarts in 2012, the site is expected to turn out 20 000 metric tons of rare earth metals each year, says CEO Mark Smith. But the research site HardAssetsInvestor estimates that ...
absorption spectra, consists of minerals in which the cerium group ele-ments predominate. This type, of which monazite and bastnaesite are examples, is characterizedby the absorption spectra of neodymium, and to a lesser degree by that of praseodymium. The distribution the rare earths in nature closelv follows the Oddo-Harkins rule whereby the …
Raman spectra of a series of cubic rare earth sesquioxides RE 2 O 3 (RE=Eu, Gd, Dy, Ho, Er, Tm, Yb, Lu, Sc and Y) were investigated by Raman spectroscopy with both 532 and 785 nm laser lines. Abundant additional bands due to laser-excited luminescence were observed. For Eu 2 O 3, Dy 2 O 3, Ho 2 O 3, Er 2 O 3, Tm 2 O 3 …
A cornerstone of the program was a $35 million award, in February 2022, to MP Materials to design and build a facility to extract and process rare-earth elements from ore at its Mountain Pass mine ...
U.S. Geological Survey news release "Going Critical". The rare earth elements (REE) are a set of seventeen metallic elements. These include the fifteen lanthanides on the periodic table plus scandium and yttrium. …
The multiplets of energy levels for electronic states on each rare-earth ion create a rich spectrum of light emission, most of it in the visible range of the …
For rare earth luminescent materials, electrons migrate from the filled molecular orbitals of ligands (oxygen, halogen, etc.) to the partially filled 4f shells of the …
The oxyhydrogen flame spectra of all the rare earths except cerium plus the elements . 382 ATOMIC EMISSION AND ABSORPTION SPECTROMETRY [6 yttrium and scandium have been observed by Rains et al. [14]. They aspirated 4-methyl-2-pentanone solutions of the rare earths into an oxyhydrogen flame. Rains et al. deduced
In conclusion, this special issue focuses on recent progress made with rare earth luminescent materials and considers designs, preparation methods and …
earths in glasses, we have exam.ined, on a preliminary basis, the absorption spectra o f ·a phosphate glass containing varying concentrations of the rare earths.
For rare earths, significant quenching occurs when the difference in energies between electronic levels is approximately equal to the energy of four phonons [35, 36]. The energy difference between ...
Sulfuric acid is necessary for extracting heavy metals such as nickel, cobalt, and rare earths for batteries, magnets, and other renewable-energy technologies. The world's needs are going up ...
Abstract. ABSORPTION spectra of rare-earth ions have been increasingly studied over recent years because of their presentation of band and line absorption in the visible region. Much work has been ...
The spectral of the rare earths have been photographed under controlled excitation so that either the spectra of the doubly or triply ionized elements are brought out with maximum intensity. A mild excitation is used in addition to give the first and second spectra for comparison. Some regularities are immediately apparent and vary very gradually …
An investigation of spectra, radiative and autoionization characteristics for the rare-earth elements is of a great interest as for development atomic spectroscopy …
The present status of our knowledge of the structure of the spectra of the doubly and triply ionized spectra of the rare earths is derived partly from experimental data of the emission spectra of the free ions which provide the energy level scheme in great detail but are difficult and laborious to analyze. For the lower levels knowledge of the structure comes …
Handbook on the Physics and Chemistry of Rare Earths, edited by K.A. Gschneidner, Jr. and L. Eyring (c) North-Holland Publishing Company, 1979 Chapter 24 THE ABSORPTION AND FLUORESCENCE SPECTRA OF RARE EARTH IONS IN SOLUTION William T. CARNALL Chemistry Division, Argonne National Laboratory, …
