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Journal articles on the topic 'Rare earth metals – Spectra'

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Published: 4 June 2021
Last updated: 12 February 2022

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1

Tick, P. A. "Optical absorption of rare-earth-doped BeF2 glasses." Journal of Materials Research 1, no. 1 (February 1986): 139–43. http://dx.doi.org/10.1557/jmr.1986.0139.

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BeF2 glasses are potentially useful materials for light transmission in the near infrared region of the spectrum. While the intrinsic attenuation of BeF2 is thought to be much lower than silica, the optimum wavelength will be further in the infrared, near 2.1 μ. In this spectral region impurities other than transition metals may be important—rare earths, for example. The data required to estimate the contributions to attenuation are normally not available; hence it is the purpose of the present work to provide that information. Using a binary BeF2/ThF4 glass, the optical absorption spectra of a number of rare earths are measured. The experimental procedures, optical spectra, and absorption strength are described.
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2

Zhao, Y., Y. Wang, H. Jin, L. Yin, X. Wu, Y. Ma, and P. D. Townsend. "Thermoluminescence spectra of rare earth doped magnesium orthosilicate." Journal of Alloys and Compounds 797 (August 2019): 1338–47. http://dx.doi.org/10.1016/j.jallcom.2019.05.173.

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3

Della Valle, F., and S. Modesti. "Exchange-excitedf-ftransitions in the electron-energy-loss spectra of rare-earth metals." Physical Review B 40, no. 2 (July 15, 1989): 933–41. http://dx.doi.org/10.1103/physrevb.40.933.

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4

Regulska, Elzbieta, Joanna Breczko, Anna Basa, and Alina Teresa Dubis. "Rare-Earth Metals-Doped Nickel Aluminate Spinels for Photocatalytic Degradation of Organic Pollutants." Catalysts 10, no. 9 (September 2, 2020): 1003. http://dx.doi.org/10.3390/catal10091003.

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Visible-light-activated photocatalysts based on samarium-doped, europium-doped, and gadolinium-doped nickel aluminates (SmNA, EuNA, GdNA) were synthesized. The spinel crystalline structures of the doped mixed metal oxides were demonstrated by X-ray diffraction (XRD) and transmission electron microscopy (TEM) analysis. The presence of the rare-earth metals (REMs) was confirmed by the energy-dispersive X-ray (EDX) studies. Ultraviolet-visible-near-infrared (UV-Vis-NIR) spectra revealed that the REMs-doped catalysts absorb in the full solar spectrum range covering both visible and near infrared wavelengths. Scanning electron microscopy (SEM) visualized the profound morphological alterations of the doped nickel aluminate samples. Consequently, the pore volume and the Brunauer-Emmett-Teller (BET) surface area decreased, while nanoparticles sizes increased. Fourier-transform infrared spectroscopy (FTIR) exposed that surfaces of REMs-doped nickel aluminates are rich in hydroxyl groups. Finally, the photocatalytic performance was notably increased through doping nickel aluminate (NA) with REMs; the highest activity was observed for EuNA.
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5

LAWRENCE, JON. "INTERMEDIATE VALENCE METALS." Modern Physics Letters B 22, no. 13 (May 30, 2008): 1273–95. http://dx.doi.org/10.1142/s0217984908016042.

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The ground state of rare earth intermediate valence (IV) metals is that of a heavy mass Fermi liquid. The transport, optical conductivity, dHvA signals, and Q-resolved neutron spectra reflect the existence of a Fermi surface with strongly renormalized masses and a hybridization gap. On the other hand, properties such as the susceptibility, specific heat, valence and spin dynamics that are dominated by the spin fluctuations, which are highly localized, can be understood qualitatively (and sometimes quantitatively) as those of a collection of non-interacting Anderson/Kondo impurities. Anomalies exist in some compounds both in the low temperature behavior and in the rate of crossover from Fermi liquid to local moment behavior which may reflect non-universal behavior of the Anderson lattice.
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6

Choi, Sung Woo, Shuichi Emura, Shigeya Kimura, Moo Seong Kim, Yi Kai Zhou, Nobuaki Teraguchi, Akira Suzuki, Akira Yanase, and Hajime Asahi. "Emission spectra from AlN and GaN doped with rare earth elements." Journal of Alloys and Compounds 408-412 (February 2006): 717–20. http://dx.doi.org/10.1016/j.jallcom.2005.01.091.

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7

Kovács, Attila, Christos Apostolidis, and Olaf Walter. "Comparative Study of Complexes of Rare Earths and Actinides with 2,6-Bis(1,2,4-triazin-3-yl)pyridine." Inorganics 7, no. 3 (February 26, 2019): 26. http://dx.doi.org/10.3390/inorganics7030026.

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Complexes of group III metals (rare earth and actinides) with 2,6-bis(5,6-dipropyl-1,2,4-triazin-3-yl)pyridine (BTP) have been investigated by computational (DFT) and, in limited cases, by experimental (FT-IR, X-ray) techniques with the goal of determining the characteristics of metal–ligand interactions. The DFT calculations using the M062X exchange-correlation functional revealed that metal–ligand distances correlate with the ionic radii of the metals, in agreement with available X-ray diffraction results on the Sc, Y, La, U, and Pu complexes. A related blue-shift trend could be observed in seven characteristic bands in the IR spectra associated with metal–ligand vibrations. The computations uncovered considerable charge transfer interactions, particularly in the actinide complexes, as important covalent contributions to the metal–ligand bonding. The covalent character of the metal–ligand bonds decreases in the actinides, from U to Cm.
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8

Ferenc, Wieslawa, Agnieszka Walkóv-Dziewulska, and Janusz Chrusciel. "Spectral and thermal behaviors of rare earth element complexes with 3,5-dimethoxybenzoic acid." Journal of the Serbian Chemical Society 68, no. 10 (2003): 751–63. http://dx.doi.org/10.2298/jsc0310751f.

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The conditions for the formation of rare earth element 3,5-dimethytoxybenzoates were studied and their quantitative composition and solubilities in water at 293 K were determined. The complexes are anhydrous or hydrated salts and their solubilities are of the orders of 10-5 ? 10-4 mol dm-3. Their FTIR, FIR and X-ray spectra were recorded. The compounds were also characterized by thermogravimetric studies in air and nitrogen atmospheres and by magnetic measurements. All complexes are crystalline compounds. The carboxylate group in these complexes is a bidentate chelating ligand. On heating in air to 1173 K, the 3,5-dimethoxybenzoates of rare earth elements decompose in various ways. The hydrated complexes first dehydrate to form anhydrous salts which then decompose in air to the oxides of the respective metals while in nitrogen to mixtures of carbon and oxides of the respective metals. The complexes are more stable in air than in nitrogen.
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9

Садагов, А. Ю., Т. А. Гойдина, В. А. Асеев, Н. В. Никоноров, Ю. К. Федоров, М. М. Чугунова, and А. Д. Левин. "Меры на основе стекол, активированных ионами редкоземельных элементов, для калибровки флуоресцентных и рамановских спектрометров." Журнал технической физики 128, no. 10 (2020): 1535. http://dx.doi.org/10.21883/os.2020.10.50028.145-20.

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The results of the development of fluorescence reference materials based on phosphate matrix glasses activated by rare-earth metal ions are presented. Reference materials are intended for spectral correction of emission spectra, systematic monitoring of sensitivity fluctuations of spectrofluorimeters. The possibility of their use for calibrating Raman spectrometer is being considered.
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10

Weingärtner, Roland, Oliver Erlenbach, Francisco De Zela, Albrecht Winnacker, Isabel Brauer, and Horst P. Strunk. "Cathodoluminescence Measurements and Thermal Activation of Rare Earth Doped (Tb3+, Dy3+ and Eu3+) a-SiC Thin Films Prepared by rf Magnetron Sputtering." Materials Science Forum 527-529 (October 2006): 663–66. http://dx.doi.org/10.4028/www.scientific.net/msf.527-529.663.

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We present comprehensive cathodoluminescence measurements from thin amorphous a- SiC films doped with rare earths. The a-SiC films were prepared by rf magnetron sputtering using a high purity SiC wafer in high purity argon atmosphere (5N, pressure approx. 0.2 mbar). The rare earth doping (Tb, Dy and Eu concentrations were below 2%) was performed by placing respective rare earth metal pieces of appropriate size onto the Silicon Carbide wafer. The rare earth ion emissions cover the colors green (Tb), yellow (Dy) and red (Eu). The optical and related structural properties of the films are correlated by means of high resolution transmission electron microscopy in combination with cathodoluminescence measurements in a scanning electron microscope. In addition, the corresponding compositions are determined by energy-dispersive x-ray analysis. The cathodoluminescence spectra of the rare earth 3+ ions are recorded in the visible at 20°C in the asgrown condition and after annealing treatments in the temperature range from 300°C to 1050°C by steps of 150°C. The anneal-related changes in the cathodoluminescence emission spectra and in the microstructure of the films are addressed. The SiC films show amorphous structure almost independent of the annealing treatment. Optimal annealing temperature for emissions of Tb3+ doped a-SiC were derived to be 600°C whereas Dy3+ and Eu3+ emissions increase at least up to 1050°C.
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11

Chakraborty, Arup, Chol-Sam Jong, Nirmal Ganguli, and I. Dasgupta. "A comparative study of magnetic and optical properties of Mn-, Gd-, and Nd-doped ZnO nanowires." International Journal of Modern Physics B 31, no. 01 (January 10, 2017): 1650241. http://dx.doi.org/10.1142/s0217979216502416.

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We present a comparative study of magnetism and optical properties for [Formula: see text] transition metal (TM) (Mn)-doped and [Formula: see text] rare-earth metals (Gd and Nd)-doped ultrathin ZnO nanowires using ab-initio density functional calculation. Our calculations indicate Nd-doped ZnO nanowires with oxygen vacancies are more favorable for ferromagnetism. Calculations including spin–orbit coupling for Nd-doped ZnO nanowires reveal not only giant anisotropy where magnetism parallel to the nanowire axis is found to be favorable but also stabilized ferromagnetism. We have calculated the absorption spectra for Mn-, Gd- and Nd-doped ZnO nanowires and found that the absorption intensity increases upon increasing the concentration of dopant ions. While Mn-doped ZnO nanowire allows absorption of light in the large energy window ranging from visible to ultraviolet, Gd- and Nd-doped systems absorb light primarily in the ultraviolet region. Our result indicates transition-metal-doped as well as rare-earth-doped ZnO nanowires may be ideal for spintronics and optoelectronic devices.
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12

Tchang-Brillet, W. Ü. Lydia, Ali Meftah, Djamel Deghiche, Jean-François Wyart, Christian Balança, Norbert Champion, and Christophe Blaess. "Laboratory studies of Vacuum Ultra-Violet (VUV) emission spectra of heavy element ions." Proceedings of the International Astronomical Union 15, S357 (October 2019): 84–88. http://dx.doi.org/10.1017/s1743921320000307.

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AbstractReliable spectroscopic data are needed for interpretation and modeling of observed astrophysical plasmas. For heavy element ions, which have complex spectra, experimental data are rather incomplete. To provide valuable fundamental quantities, such as precise wavelengths, level energies and semi-empirical transition probabilities, we are carrying out laboratory studies of high-resolution VUV emission spectra of moderately charged ions of transition metals and rare earth elements. Experimental and theoretical methods are summarized. Examples of studies are described.
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13

Moser, Hans R., and Göran Wendin. "Theoretical models for intensities ofd→ftransitions in electron-energy-loss spectra of rare-earth and actinide metals." Physical Review B 44, no. 12 (September 15, 1991): 6044–61. http://dx.doi.org/10.1103/physrevb.44.6044.

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14

Lv, Yu Guang, Li Zhang, Kui Lin Lv, Shu Jing Zhou, Du A, Ji Hui Zheng, Peng Jiao, Jia Yu Hou, and Yui Zhu. "Synthesis, Characterization and Property of Nano Rare Earth Terbium Complex with Gatifloxacin." Applied Mechanics and Materials 541-542 (March 2014): 185–89. http://dx.doi.org/10.4028/www.scientific.net/amm.541-542.185.

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Rare earth metal complexes have special characteristics, such as extremely narrow emission bands and high internal quantum efficiencies, which are suitable to be used as the emission materials, chemistry and biological technology. Ternary nano complex of terbium gatifloxacin phenanthroline was synthesized.The composition and structure of ternary complex were characterized by element analysis, Mass Spectrometry (MS), UltraViolet Absorption Spectrometry (UV) and fluorescence spectra(FS). The influences of solubility, thermal stability and luminescent properties of complex as well as addition of phenanthroline secondary ligands on the fluorescence spectra of the ternary complexes were studied. The results of fluorescence spectra analysis showed that partial energy was transferred from Characterization to terbium ions by intramolecular energy transfer processes, meanwhile, the addition of phenanthroline can effectively increase the luminescence intensity of terbium icons. The complex possessed well luminescence and showed characteristic emission peaks of Tb3+ under UV light excitation and emitted strong green fluorescence. Moreover, in an ITO/PVK/Tb(GFLX)3Phen/Al device, Tb3+ ion can be excited by intramolecular ligand-to-metal energy transfer process. The main peak of emission at 545 nm is attributed to 5D0→7F2 transition of the Tb3+ ion, and this process results in the enhancing green emission. Biological actrivity properties of the rare earth complex was well studied.
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15

PATCHETT, A. J., S. S. DHESI, R. I. R. BLYTH, and S. D. BARRETT. "POSSIBLE EVIDENCE FOR A VALENCE BAND SATELLITE IN PHOTOEMISSION SPECTRA FROM Sc(0001)." Surface Review and Letters 01, no. 04 (December 1994): 649–53. http://dx.doi.org/10.1142/s0218625x94000862.

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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.
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16

Cheremisina, O. V., V. V. Sergeev, D. A. Alferova, and A. P. Ilyna. "Quantitative x-ray spectral determination of rare-earth metals in products of metallurgy." Journal of Physics: Conference Series 1118 (December 2018): 012012. http://dx.doi.org/10.1088/1742-6596/1118/1/012012.

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17

Гончарь, Л. Э. "Влияние орбитального упорядочения на спектры магнитного резонанса в зарядово-упорядоченных и фрустрированных манганитах." Физика твердого тела 61, no. 5 (2019): 841. http://dx.doi.org/10.21883/ftt.2019.05.47577.24f.

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A theoretical study of the interrelation of the crystal structure, charge, orbital, and magnetic subsystems in R1–xAxMnO3 charge-ordered manganites has been carried out (where R3+ is the rare earth ion, A2+ is the alkaline earth metal ion, x = 0.5, 2/3). The model of orbital-dependent exchange interactions and single-ion anisotropy is used. The presence of quasi-low-dimensional magnetic structures is exhibited. The spin waves spectra and antiferromagnetic resonance spectra are calculated.
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18

Wu, Yi, Xinli Liu, and Dongmei Cui. "Side-Arm Assisted Anilido-Imine Based Rare-Earth Metal Complexes for Isoprene Stereoselective Polymerization." Molecules 26, no. 14 (July 8, 2021): 4154. http://dx.doi.org/10.3390/molecules26144154.

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Anilido-imine ligands o-C6H4(NHAr1)(CH=NAr2), in which Ar1 is 2,6-diisopropylbenzyl group and Ar2 contains fluorine (HL1) or methoxyl (HL2) group on ortho-position of phenyl substituent, were synthesized for constructing rare-earth metals based complexes of 1a–1c (HL1 based Sc, Lu, Y) and 2a–2c (HL2 based Sc, Lu, Y). Based on their NMR spectra and X-ray single-crystal structures, the side-arm group of -F and -OMe is identified to chelate to the corresponding central metal. The twisted angles between two planes formed by chelated heteroatoms (N, N, F for HL1 and N, N, O for HL2) are observed, in which the largest dihedral angle (53.3°) for HL1-Y and the smallest dihedral angle (44.32°) for HL2-Sc are detected. After being activated by AliBu3 and [Ph3C][B(C6F5)4], these catalysts showed great activity for isoprene polymerization. Bearing the same ligand HL1, smaller scandium based complex 1a and middle size of lutetium based 1b provided lower cis-1,4-selectivity (57.3% and 64.2%), larger yttrium complex 1c displayed high cis-1,4-selectivity (84%). Chelating by crowded HL2, small size of scandium complex 2a provided impressive trans-1,4-selectivity (93.0%), middle lutetium based 2b displayed non-selectivity and larger yttrium complex 2c showed clear cis-1,4-selectivity (83.3%). Moreover, 2a/AliBu3 system showed the quasi-living chain transfer capability.
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19

Kumari, Aarti, Kamala Kanta Sahu, and Sushanta Kumar Sahu. "Solvent Extraction and Separation of Nd, Pr and Dy from Leach Liquor of Waste NdFeB Magnet Using the Nitrate Form of Mextral® 336At in the Presence of Aquo-Complexing Agent EDTA." Metals 9, no. 2 (February 25, 2019): 269. http://dx.doi.org/10.3390/met9020269.

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：Solvent extraction and separation of Pr, Nd and Dy from a synthetic leach solution of spent NdFeB magnet from wind turbines in the presence of aquo-complexing agent Ethylenediaminetetraacetic acid (EDTA) was studied using the nitrate form of Mextral® 336At ([336At][NO3]) as an extractant. The effect of different process parameters such as pH, extractant, nitrate, and EDTA concentrations on the extraction of Pr, Nd and Dy was studied. The extraction of these rare earths elements follows the order Pr > Nd > Dy, whereas EDTA forms stable complexes in the order Dy > Nd > Pr. The synergy of these two effects improved the selectivity among these elements as compared to when no aquo-complexing agent was used. The mechanism of extraction of rare earth elements was established by slope analysis method. The Fourier-Transform Infrared Spectroscopy (FTIR) spectra of [336At][NO3] and extracted Nd complex were recorded to understand the interaction of extractant with rare earth metal ions in the organic phase.
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20

Thompson, L. C., J. R. Marvin, and N. C. Bettenberg. "Absorption spectra of solid rare earth complexes obtained from the inner filter effect on luminescence." Journal of Alloys and Compounds 180, no. 1-2 (March 1992): 229–34. http://dx.doi.org/10.1016/0925-8388(92)90385-m.

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21

Leapman, R. D., and D. E. Newbury. "Trace analysis of transition elements and rare earths by parallel EELS." Proceedings, annual meeting, Electron Microscopy Society of America 50, no. 2 (August 1992): 1250–51. http://dx.doi.org/10.1017/s0424820100130882.

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It has been realized for some years that electron energy loss spectroscopy (EELS) offers the potential for a highly sensitive microanalytical technique. Here, we present measurements from some NIST glass standard reference materials showing that EELS provides both high spatial resolution and trace sensitivity for a wide range of elements including the 3-d transition metals and the lanthanides.Specimens were prepared by grinding the glass and depositing the powder on to thin carbon support films. The energy loss spectra were collected by means of a Gatan 666 parallel-detection spectrometer attached to a VG Microscopes HB501 scanning transmission electron microscope (STEM) operating at 100 keV beam energy. This arrangement gave an energy resolution of approximately 0.4 eV limited by the spread of the field-emission source. Large spectral intensities were obtained by setting the probe current to about 8 nA and the collection semi-angle to 20 mrad. In order to eliminate possible hydrocarbon contamination the specimens were cooled to -160 C.
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22

Chen, Xin, Chiming Wang, Dongdong Qi, and Jianzhuang Jiang. "Raman spectra of rare earth double-decker complexes with porphyrinato and 2,3-naphthalocyaninato ligands." Journal of Porphyrins and Phthalocyanines 23, no. 03 (March 2019): 260–66. http://dx.doi.org/10.1142/s1088424619500081.

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The Raman spectra of the mixed (naphthalocyaninato)[tetrakis(4-[Formula: see text]-butylphenyl)porphyrinato] rare earth double-decker compounds M(Nc)(TBPP) (M = Y, La, Ce, Eu, Dy, Lu) were studied with Density Functional Theory for the first time. The results reveal the fingerprint band for naphthalocyanine to be around 1455–1615 cm[Formula: see text] and porphyrin around 693–749 cm[Formula: see text]. Coupled Nc–Por ring–ring interaction vibration modes are also detected at 1470–1522 cm[Formula: see text], owing to the stretching between the central metal and the N atoms. These vibration modes are recognized as the dominating components in the Raman spectra of those double-decker compounds.
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23

Isago, Hiroaki. "Spectral study on one-electron-oxidized di(phthalocyaninato)rare-earths(III)." Journal of Porphyrins and Phthalocyanines 16, no. 07n08 (July 2012): 861–69. http://dx.doi.org/10.1142/s1088424612500861.

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Nine double-decker bis(phthalocyaninato)rare-earth(III) complexes, [M(pc)2] (green radical species; M = Sc, Y, La, Pr, Sm, Eu, Tb, Ho, Yb ) have been electrochemically and spectro-electrochemically investigated in CH2Cl2 . All of them show one oxidation and three reduction waves, which involve phthalocyanine macrocycles. Apart from the lanthanum derivative, the first oxidation and reduction potentials show linear cathodic shift with an increase in ionic radius of the central metal (ri), whereas the second and third reduction little depend on ri. Electrochemical oxidation (around the oxidation potential) and chemical oxidation produced the same red~orange species (depending on the central metal). Their optical absorption spectra show three characteristic bands in 400~600, 600~750, and 800~1200 nm in visible and near-infrared region and their peak positions (in cm-1) linearly depend on ri (except for La). Assignment of these bands has been done based on magnetic circular dichroism spectroscopy and the electrochemical data.
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24

Rez, Peter. "Scattering Cross Sections in Electron Microscopy and Analysis." Microscopy and Microanalysis 7, no. 4 (July 2001): 356–62. http://dx.doi.org/10.1007/s10005-001-0003-5.

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AbstractThe scattering cross section is the fundamental measure of the strength of a scattering interaction. All scattering in electron microscopy arises from the Coulomb interaction, and scattering cross sections, whether elastic or inelastic, will therefore all have common features. Simple forms of both elastic and inelastic cross sections are reviewed in the context of high resolution and analytical microscopy. Some recent developments, such as the calculation of Fano resonances in electron energy loss spectra of transition metals and rare earth elements are also discussed.
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25

Grigoryeva, A. V., A. V. Volkov, and K. Y. Murashov. "Rare-earth elements in Cu-Ni ores of the Norilsk region." Arctic: Ecology and Economy 11, no. 1 (March 2021): 76–89. http://dx.doi.org/10.25283/2223-4594-2021-1-76-89.

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The deposits of the Norilsk region are confined to the marginal northwestern part of the Siberian platform and are associated with the manifestation of the Early Mesozoic trap volcanism. Sulfide mineralization is concentrated in the intrusive facies of the volcano-intrusive complex. Four main types of Cu-Ni ores are distinguished according to textural features: massive, vein-disseminated, brecciated, and disseminated. The main types of Cu-Ni ores differ significantly from each other in the chemical composition and content of rock- and ore-forming components. The enrichment ratios of ore trace elements in the Oktyabrskaya and Talnakhskaya vein-disseminated ore mainly reach hundreds (S, Pt, Au, Se,Te, Pb, As, Sn, Mo) and thousands (Ni, Cu, Ag, Pd) times. A rather high enrichment of all types of Bi, Re and Cd ores has been revealed, which are potentially industrially significant as high-tech metals, and can be promising for associated mining. The amount of rare-earth elements (REE) in ores is several times less than in the upper crust and more than in the primitive mantle. The concentration of rare earths in the main types of ores, with the exception of massive ones, exceeds the level of the chondrite standard, and REE fractionation is weak. The distribution spectra of chondrite-normalized REEs have a slight negative slope: the total content of light REEs is higher than that of heavy ones. The similarity of the geometry of the REE spectra of massive, vein-disseminated, brecciated and disseminated types of ores containing a significant admixture of host rocks indicates the inheritance of the REE composition in ores from the host rocks. In the disseminated ores of common taxite gabbro-dolerites, the Eu anomaly is present in the Kharaelakhsky (Oktyabrskoye Deposit) and Talnakhsky (Talnakhskoye Deposit) intrusions, it is positive, and in the Norilsk I Intrusive (in the same rocks), it is negative. Higher concentrations of REEs and significant fractionation of light and heavy rare elements are typical for host contact-metamorphic and metasomatic rocks with vein-disseminated (exocontact) ores. For olivine-free hornfels and skarns in brecciated ores, as well as for vein-disseminated ores, significant fractionation of light REEs with relatively heavy ones and a pronounced Eu minimum are characteristic. In massive ores, the distribution of REEs is determined by the composition of xenoliths.
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26

Wu, Kai, Dong Li, Xiaobin Guo, Baoshan Cui, Jijun Yun, Yalu Zuo, and L. Xi. "Temperature-Dependent Magnetic Damping Constant of Fe2Co Films Doped by Rare-Earth Yb." SPIN 07, no. 01 (March 2017): 1740002. http://dx.doi.org/10.1142/s2010324717400021.

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The temperature-dependent magnetic properties are investigated in amorphous (Fe2Co)[Formula: see text]Ybx ([Formula: see text], 0.64) thin films with in-plane uniaxial anisotropy. The decreases of saturation magnetization and easy axis coercivity with increasing temperature were observed and quite well explained by the Bloch’s law of [Formula: see text] dependence based on three-dimensional (3D) spin wave excitations and the thermally activated domain wall motion model of [Formula: see text] dependence, respectively. The decrease of in-plane uniaxial anisotropy constant is also observed and can be quite well fitted at temperature below 300[Formula: see text]K. The magnetic damping constant, which was deduced from the angular dependent ferromagnetic resonance spectra, shows a minima over the temperature range 100–435[Formula: see text]K, just like the previous results from 3D-transition metals based on Kamberský’s torque-correlation model. However, a positive correlation between damping and the in-plane uniaxial anisotropy constant was obtained with a clear deviation from the linear relationship. This deviation indicates that temperature-dependent damping and anisotropy may have different origins instead of the common source of the temperature-dependent spin-orbital coupling strength.
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27

Demazeau, Gérard, Alexey Baranov, Igor Presniakov, and Alexey Sobolev. "High Oxygen Pressures and the Stabilization of the Highest Oxidation States of Transition Metals – Mössbauer Spectroscopic Characterization of the Induced Electronic Phenomena." Zeitschrift für Naturforschung B 61, no. 12 (December 1, 2006): 1527–40. http://dx.doi.org/10.1515/znb-2006-1209.

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High oxygen pressures are a fruitful tool for the stabilization of the highest formal oxidation states of transition metals (Mn+) leading to the strongest chemical bonds; the improvement of the Mn+-O bond covalency induces different electronic phenomena. Among the physical characterizations applied to investigate such phenomena, 57Fe and 119Sn Mössbauer spectra are evaluated for studying unusual electronic configurations, orbital ordering, charge disproportionation and insulator-metal transitions in the perovskites series of 57Fe doped RENiO3 nickelates (RE = rare earths, Y and Tl) and 119Sn doped AEFeO3 ferrates (AE = Ca, Sr).
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28

Worsztynowicz, Adam, Slawomir M. Kaczmarek, and Elzbieta Tomaszewicz. "Magneto-Chemical Properties of Some New Ni and Co Rare-Earth Metal Tungstates." Solid State Phenomena 128 (October 2007): 207–12. http://dx.doi.org/10.4028/www.scientific.net/ssp.128.207.

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New d-electron and rare-earth metal tungstates (CoRE2W2O10; CoRE4W3O16; Co2RE2W3O14 and NiRE2W2O10) were studied by the IR and EPR spectroscopy methods. The IR absorption bands with their maxima can be assigned to the symmetric and asymmetric stretching modes of W-O bonds in the joint of WO6 octahedra and also to the oxygen double WOOW bridge bonds. The wide, unstructured EPR powder spectra of these compounds and their temperature evolution have been analyzed and interpreted.
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29

Song, Kai, Han Yu, Jingyi Zhang, Yumeng Bai, Yanjun Guan, Jingbo Yu, and Liquan Guo. "Rosebengal-Loaded Nanoporous Structure Based on Rare Earth Metal-Organic-Framework: Synthesis, Characterization and Photophysical Performance." Crystals 10, no. 3 (March 8, 2020): 185. http://dx.doi.org/10.3390/cryst10030185.

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A rosebengal-modified nanoporous structure was designed and constructed. This composite structure consisted of an organic sensitizer based on rosebengal and a supporting host of rare earth metal-organic-framework (MOF). It was identified by means of its x-ray diffraction (XRD) pattern, Infrared (IR) spectra, thermal stability and photophysical measurements. Its absorption was increased by 2,4,6-trinitrophenol. Its rosebengal emission was proportionally increased. But its rare earth emission was well-preserved, offering ratiometric signals. These two sensing modes exhibited linear response and good selectivity with a limit of detection (LOD) of 1.9 μM. Its sensing nature was confirmed as the combination of increased rosebengal emission and rare earth emission quenching effect triggered electron-deficient molecules. This nanoporous structure was superior to traditional ones owing to its double sensing modes.
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30

Yang, Xiao Feng, Yong Sheng Tan, Ze Bo Fang, Jian Jun Wang, He Nan Ni, Zhi Bin Li, and Tai Hong Chen. "Reliability Study of the Band Gap of Rare Earth Oxides Measured by XPS Spectra." Key Engineering Materials 562-565 (July 2013): 891–95. http://dx.doi.org/10.4028/www.scientific.net/kem.562-565.891.

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Subscript text Subscript textEr2O3、Tm2O3 and Yb2O3 films were deposited on Si (100) and quartz substrates by radio frequency magnetron technique. The energy gaps of the films were measured by X-ray photoelectron spectroscopy (XPS) and optical methods. The energy gaps of Er2O3、Tm2O3 and Yb2O3 are found to be 6.3±0.1、5.8±0.1 and 7.1±0.1 eV by optical measurements. For XPS measurements, the energy gaps of the films are 6.2±0.2、6.0±0.2 and 6.9±0.2 eV, respectively. The results show that using XPS to measure the energy gap of rare earth metal oxide film is feasible in an allowable deviation.
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31

Hufner, S. "Screening in the valence-band photoemission spectra of light rare earths." Journal of Physics F: Metal Physics 16, no. 1 (January 1986): L31—L34. http://dx.doi.org/10.1088/0305-4608/16/1/006.

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32

Lafane, Slimane, Tahar Kerdja, Samira Abdelli-Messaci, S. Malek, and M. Maaza. "Sm1-xNdxNiO3 Thin Films Deposition by KrF Laser Ablation." Materials Science Forum 609 (January 2009): 27–31. http://dx.doi.org/10.4028/www.scientific.net/msf.609.27.

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The perovskites RNiO3 (R rare earth ≠ La) are classified as a phase transition metal-insulator. The transition temperature is modulated by the size of the rare earth. The use of compound R1-xR'xNiO3 can vary transition temperature on a wide thermal range depending on the concentration of the two rare earths. The Sm1-xNdxNiO3 (x = 0.45) thin layers have been carried out on (100) silicon substrates by KrF laser ablation (λ = 248 nm, 25ns) at two different fluences 2 and 3 Jcm-2. The oxygen pressure and the target-substrate distance have been maintained at 0.2 mbar and 4 cm respectively. The deposition temperature has been set at 500 ° C. The obtained layers were characterized by X-ray diffraction, atomic force microscopy and Rutherford back scattering diagnostics. The resistivity Measurements were carried out by the conventional four-probe method. The XRD spectra revealed the presence of an ideal cubic perovskite phase. The RBS analysis showed that the deposited layers are rich in oxygen. A correlation between the morphology properties of the deposited layers and the plasma dynamics studied by fast imaging has been found.
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33

Dzhevaga, N. V., and O. L. Lobacheva. "Solvent extraction of europium(III) from technogenic solutions with the use of surfactants." Fine Chemical Technologies 15, no. 4 (September 12, 2020): 51–58. http://dx.doi.org/10.32362/2410-6593-2020-15-4-51-58.

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Objectives. The extraction and separation of rare-earth metals is a complicated process that requires a multidisciplinary and detailed investigation. Liquid-liquid extraction with the use of surfactant, along with the thermodynamic analysis of the parameters is considered a promising approach. The extraction and separation of rare-earth metals from low-concentration solutions represents an attractive research opportunity. The extraction of europium(III) from nitric acid solutions in the form of dodecyl sulfates has been experimentally studied. This work focuses on the study of fundamental and alternative sources of rare-earth metals and their extraction and separation.Methods. The extraction was performed on a top drive ES-8300 D equipment for 30 min at about 700 rpm. Infrared spectroscopy (Nicolet 6700 spectrometer) was used to determine the type of salts extracted into the organic phase. Extraction was studied in solutions with single cations and with a combination of the target element and interfering cations. For the latter, the concentrations of extracted elements in the aqueous phase were determined by optical emission spectroscopy with inductively coupled plasma on an ICPE-9000 (Shimadzu) spectrometer. The spectrometer was calibrated using standard samples for ICP CertiPUR (Merck).Results. The dependence of the distribution and separation coefficients of rare-earth metals during extraction on the pH value of the aqueous phase at equilibrium was investigated. Moreover, the form in which the elements are extracted was analyzed based on thermodynamic parameters. The minimum concentration of the target component in the aqueous phase was observed at pH 4.0. In general, the dependence of the distribution coefficient on the pH value of the medium is poorly expressed over the entire range of the pH range of the water phase. Based on the spectra of spent and pure isooctyl alcohol, it was concluded that europium dodecyl sulfates are extracted into the organic phase as Eu(C12H25OSO3) 3 solvates.Conclusions. The extraction of europium(III) from nitric acid solutions in the form of dodecyl sulfates was demonstrated. The advantages of the proposed method are the possibility of selective extraction of the target component from dilute solutions and the use of an easily available surfactant (sodium dodecyl sulfate). The efficiency of extraction of europium dodecyl sulfates was maximal in the pH range from 2.0 to 7.5, which reflects a weak dependence on the acidity of the aqueous phase. In addition, in the highly alkaline pH region, the extraction efficiency is reduced.
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34

Pisarski, Wojciech A., Karolina Kowalska, Marta Kuwik, Justyna Polak, Ewa Pietrasik, Tomasz Goryczka, and Joanna Pisarska. "Novel Multicomponent Titanate-Germanate Glasses: Synthesis, Structure, Properties, Transition Metal, and Rare Earth Doping." Materials 13, no. 19 (October 4, 2020): 4422. http://dx.doi.org/10.3390/ma13194422.

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Novel multicomponent titanate-germanate glasses singly doped with transition metal (Cr3+) and rare earth ions (Eu3+) were synthesized and the glass transition temperatures and thermal stability parameters were determined using DSC measurements. X-ray diffraction analysis confirmed fully amorphous nature of the received samples. Their structural and optical properties were compared with germanate glasses without TiO2. Correlation between local structure and optical properties in titanate-germanate glasses is well evidenced by FT-IR, Raman, EPR, and luminescence spectroscopy. In particular, luminescence spectra and their decays are examined for glass samples, where GeO2 was partially substituted by TiO2.
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35

WEBER, A., and H. SUHR. "THIN LANTHANUM OXIDE AND RARE-EARTH OXIDE FILMS BY PECVD OF β-DIKETONATE CHELATE COMPLEXES." Modern Physics Letters B 03, no. 13 (September 10, 1989): 1001–8. http://dx.doi.org/10.1142/s0217984989001552.

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A method for the deposition of lanthanum oxide and rare-earth (Re) oxide films using the tris[2,2,6,6-tetramethyl-3,5-heptanedionato] chelate complexes is reported. The films were characterized by metal analysis, carbon analysis, FTIR spectra, XPS and SEM micrographs. The film composition strongly depends on experimental parameters. Films deposited in an oxygen plasma at a substrate temperature of 400°C and a power density of 1.5 W/cm 2 are amorphous, transparent and show carbon contents of < 2%. If argon or hydrogen is used as carrier gas, films contain ≈ 5% carbon. With substrate temperatures < 400° C or power densities < 1.5 W/cm 2, films containing trivalent Re metal ions and considerable contamination by polymeric material are formed.
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36

Guo, Ge, Xiaolu Wu, Xiangqian Yan, Li Yan, Xiaofang Li, Shaowen Zhang, and Nannan Qiu. "Unprecedentedly High Activity and/or High Regio-/Stereoselectivity of Fluorenyl-Based CGC Allyl-Type η3:η1-tert-Butyl(dimethylfluorenylsilyl)amido Ligated Rare Earth Metal Monoalkyl Complexes in Olefin Polymerization." Polymers 11, no. 5 (May 8, 2019): 836. http://dx.doi.org/10.3390/polym11050836.

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A series of fluorenyl-based constrained-geometry-configuration (CGC) allyl-type rare earth metal monoalkyl complexes bearing the divalent anionic η3:η1-tert-butyl(dimethylfluorenylsilyl)amido (η3:η1-FluSiMe2NtBu) ligand (η3:η1-FluSiMe2NtBu)Ln(CH2SiMe3)(THF)2 (1–3) have been synthesized via the alkane elimination reaction between the FluHSiMe2NHtBu ligand and rare earth metal tri(trimethylsilylmethyl) complexes Ln(CH2SiMe3)3(THF)n. Their structures are characterized by means of NMR spectrum, elemental analyses, and X-ray diffraction. These complexes 1–3 are isostructural and isomorphous, and each of them adopts a distorted-trigonal-bipyramidal configuration containing one η3:η1-FluSiMe2NtBu ligand, one CH2SiMe3 ligand, and two THF molecules. Unlike traditional CGC allyl-type rare earth metal complexes showing no or low activity and regio-/stereoselectivity in styrene or MMA polymerization, these complexes 1–3 exhibit high catalytic activities and/or high regio-/stereoselectivities in the cis-1,4-polymerization of isoprene and myrcene or in the syndiotactic polymerization of styrene under the aid of different activators (borate or borane) and AlR3. The in situ 1H NMR spectra suggest that the exchanges of chelating ligands such as alkyl groups and divalent anionic η3:η1-FluSiMe2NtBu ligands between rare earth metal centers and Al centers result in the formation of a heterobimetallic tetraalkylaluminate complex R2Al(μ-R)2Ln(R)(μ-R)2AlR2, which is activated by activators to form a divalent cationic species [Ln(μ-R)2AlR2]2+ as a catalytically active species in the coordination–insertion polymerization of olefins.
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37

Xu, Qin, Xinyu Yang, Mingjie Zhang, and Rongping Wang. "The ability of GexGa4S96-x chalcogenide glasses dissolving rare earth probed by x-ray photoelectron spectra analysis." Materials Research Express 6, no. 8 (June 12, 2019): 085212. http://dx.doi.org/10.1088/2053-1591/ab23be.

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38

Cheng, S. C., and R. T. Wilkin. "White Lines in the Iron L2,3 Electron-Energy-Loss Spectra of Pyrite and Greigite." Microscopy and Microanalysis 4, S2 (July 1998): 562–63. http://dx.doi.org/10.1017/s1431927600022935.

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The white lines on the L2,3 absorption edges of the transition metals and on the M4,5 absorption edges of the rare earth elements are the most prominent feature in electron-energy-loss spectra (EELS). The white lines of these elements have been studied and used to determine valance and coordination of atoms in various systems. Fe-O compounds with valence 2, 3 and mixed valence states, for example, have been carefully examined and characterized. However, in spite of the importance of iron sulfides in geochemistry and environmental science, the EELS data of these compounds are not available. Pyrite (FeS2) is widespread in hydrothermal ores, modern sediments, and sedimentary rocks deposited throughout the geologic record. The ferromagnetic iron sulfide greigite (Fe3S4) is another important compound. It has been recognized as a carrier of magnetic remanence in young sediments. Sedimentary greigite may be precipitated inorganically or biogenically by magnetotactic bacteria.
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39

Etz, Edgar S., Wilbur S. Hurst, Steven J. Choquette, and Douglas H. Blackburn. "Chromium-Doped Luminescent Glasses for Raman Intensity Calibration with 785 nm Laser Excitation." Microscopy and Microanalysis 7, S2 (August 2001): 160–61. http://dx.doi.org/10.1017/s1431927600026878.

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In work reported previously we, and the McCreery Group at Ohio State University, have proposed the use of glass luminescence standards for the calibration of the Raman spectral intensity. We now have a program underway that is directed at the development of such secondary standards for the calibration of the Raman instrument response function. The first Raman intensity standard to be certified and issued by NIST this year will be for the relative intensity calibration of Raman spectra excited at 785 nm. in general, for any laser excitation wavelength, the calibration procedure is based on the use of luminescent glasses, doped with either transition metal or rare earth ions, that will furnish structureless, broad-band emission spectra upon laser excitation, over any chosen Raman range. For any selected glass standard, the intensity of the luminescence spectrum is calibrated versus the radiant output of a NIST-calibrated white light source, thereby transferring the white light calibration onto the output emission of the luminescent glass.
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40

Martin, Madhavi, Daniel Hamm, Samir Martin, Steve Allman, Gary Bell, and Rodger Martin. "Micro-Laser-Induced Breakdown Spectroscopy: A Novel Approach Used in the Detection of Six Rare Earths and One Transition Metal." Minerals 9, no. 2 (February 12, 2019): 103. http://dx.doi.org/10.3390/min9020103.

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Laser-induced breakdown spectroscopy (LIBS) was undertaken using an instrument which used a high-powered microscope to deliver the light and tightly focused the low energy laser beam onto the surface of a solid sample. A micro-plasma was generated on the surface of the sample under test even though the amount of energy/pulse from a beam of 532 nm was <1 mJ. Rare earth elements such as europium, gadolinium, lanthanum, neodymium, praseodymium, samarium, and a transition metal, yttrium, were tested. These elements are important in nuclear fission reactions especially for estimation of actinide masses for non-proliferation “safeguards”. Each element was mixed in the graphite matrix in different percentages from 1% to 50% by weight and the LIBS spectra were obtained for each composition as well as after mixing each element in the same amount using oxides of the elements. The data for the 5% mixture of the rare earth elements with graphite powder along with the transition metal has been presented in this article. A micro-LIBS approach was used to demonstrate that these rare earth elements can be identified individually and in a complex mixture in glove boxes in which the microscope LIBS instrument is housed in a nuclear research environment.
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41

Kasumov, A. M., A. I. Dmitriev, Yu M. Bataiev, M. M. Bataiev, V. M. Karavaeva, K. A. Korotkov, and A. I. Ievtushenko. "EPR study of interlayer interaction in Gd2O3/Fe nanostructure." Himia, Fizika ta Tehnologia Poverhni 12, no. 2 (June 30, 2021): 144–48. http://dx.doi.org/10.15407/hftp12.02.144.

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In this work, a nanoscale structure consisting of contacting layers of a metal of the iron subgroup and a rare earth metal oxide (REM) is considered. Such nanostructures have an interesting feature, which is that as a result of the contact of these layers, an increase in the galvanomagnetic, magneto-optical and kinetic properties of ferromagnetic metals are observed. Presumably, the enhancement is due to an increase in the magnetization of these metals, caused by the exchange f - d interaction between the unfilled f- and d-electron shells of the atoms that make up the contacting layers. The aim of this work is to find the possibility of such f - d exchange interaction by the EPR method. To compose the studied nanostructure, Fe used as it has the strongest magnetic properties in its subgroup. Gd2O3 was used as an REM oxide as one of the few oxides giving a significant signal in the EPR region. The Gd2O3/Fe nanostructure created by sequential electron-beam deposition of Gd2O3 and Fe layers on a sitall substrate. The thickness of the oxide and metal layers was 68 and 112 nm, respectively. EPR spectra were recorded at room temperature on a computerized spectrometer Radiopan 2547 SE / X at the frequency of 9.3 GHz. The set of the obtained spectra was processed using the OriginPro and MatLab programs, which confirmed their compliance with the Lorentz model. From the experimentally obtained EPR linewidth, the parameter of the exchange f - d interaction is determined under the condition of a number of assumptions. The value of the g-factor is also found. Comparison of the EPR parameters of the spectra of individual layers of Gd2O3 and Fe with the spectra of the Gd2O3/Fe nanostructure composed of them, including the value of the g factor and the exchange interaction parameter, suggests that the presence of an iron layer affects the EPR spectrum of the REM oxide layer Gd2O3. The exchange interaction parameter increases from 985 to 4685 (rel. units), the g-factor decreases from 3.5 to 2.4. The most probable reason for the change in the spectrum is the exchange f - d interaction between atoms with unfilled f- and d-electron shells that are parts of the contacting layers.
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42

Niciu, H., Dorel Radu, C. Onose, V. Maduta, Daniela Niciu, H. Stroescu, and C. S. Onose. "The Influence of the Vitreous Matrix for the Determination of the Lanthanides Doping Concentration from the Optical Transmission Spectra." Advanced Materials Research 39-40 (April 2008): 269–72. http://dx.doi.org/10.4028/www.scientific.net/amr.39-40.269.

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In contrast with transitional metals whose spectra and color depends a lot of the ligands strength field, the sensitivity of the rare earth spectra is significantly weaker. This is the reason why the color of these ions is the same whatever the basic vitreous matrix. These properties permit to establish a relation for the determination of the concentration of these ions in vitreous matrix directly from the optical transmission spectra. The paper presents some samples of silica and phosphate glasses with lanthanides content for nonlinear optical applications synthesized at a laboratory scale. VIS-NIR transmission curves are presented, for several compositions. For the correlation of the lanthanides content with the specific optical absorption peak one used a method starting from the Lambert – Beer law. For the Nd2O3 concentration determination, it was used a method proposed by D.M. Dood and D.B. Fraser for the OH groups content, with an error of +4%. For specific peaks, expressions for lanthanides concentration in ppm, related to the optical transmission were found. A possibility appears to directly find the lanthanides concentration from the absorption coefficient at specific wavelengths for each vitreous matrix. The influence of matrix is discussed.
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43

Saiganesh, Srihasam, Thyagarajan Krishnan, Golla Narasimha, Hesham Almoallim, Sulaiman Alhari, Lebaka Reddy, Koduru Mallikarjuna, Arifullah Mohammed, and Vattikuti Prabhakar. "Phytosynthetic Fabrication of Lanthanum Ion-Doped Nickel Oxide Nanoparticles Using Sesbania grandiflora Leaf Extract and Their Anti-Microbial Properties." Crystals 11, no. 2 (January 27, 2021): 124. http://dx.doi.org/10.3390/cryst11020124.

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Over the past few years, the photogenic fabrication of metal oxide nanoparticles has attracted considerable attention, owing to the simple, eco-friendly, and non-toxic procedure. Herein, we fabricated NiO nanoparticles and altered their optical properties by doping with a rare earth element (lanthanum) using Sesbania grandiflora broth for antibacterial applications. The doping of lanthanum with NiO was systematically studied. The optical properties of the prepared nanomaterials were investigated through UV-Vis diffuse reflectance spectra (UV-DRS) analysis, and their structures were studied using X-ray diffraction analysis. The morphological features of the prepared nanomaterials were examined by scanning electron microscopy and transmission electron microscopy, their elemental structure was analyzed by energy-dispersive X-ray spectral analysis, and their oxidation states were analyzed by X-ray photoelectron spectroscopy. Furthermore, the antibacterial action of NiO and La-doped NiO nanoparticles was studied by the zone of inhibition method for Gram-negative and Gram-positive bacterial strains such as Escherichia coli and Bacillus sublitis. It was evident from the obtained results that the optimized compound NiOLa-04 performed better than the other prepared compounds. To the best of our knowledge, this is the first report on the phytosynthetic fabrication of rare-earth ion Lanthanum (La3+)-doped Nickel Oxide (NiO) nanoparticles and their anti-microbial studies.
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44

Shi, Qi Song, Ben Feng Hu, Qiu Yan Liang, and Tai Qi Liu. "Synthesis, Crystal Structure and Fluorescence Property of Terbium Coordination Polymers with Pyridine-3.5-Dicarboxylic Acid." Materials Science Forum 663-665 (November 2010): 72–75. http://dx.doi.org/10.4028/www.scientific.net/msf.663-665.72.

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Rare-earth metal-organic frameworks [Tb2(pdc)3(H2O)9]n3nH2O, were synthesized and characterized by elemental analysis, IR spectra and single-crystal X-ray diffraction. The title compound consisted of one-dimensional dual-chains, in which each metal atom is nine-coordinated with oxygen atoms. The carboxylate groups of pdc provided two kinds of coordination ways as bidentate and monodentate. The solid-state photoluminescence measurement exhibited green light-emitting characteristic of terbium (III) coordination polymer, and the fluorescence intensities were stronger than that of the europium compound with the same ligand.
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45

Puzhel, A. O., V. A. Borisov, A. R. Osipov, I. V. Petlin, A. D. Kiselev, and L. N. Adeeva. "Fluoride processing of oil hydrocarbon cracking catalyst with REE concentrate extraction." Izvestiya Vuzov Tsvetnaya Metallurgiya (Universities Proceedings Non-Ferrous Metallurgy) 1, no. 1 (February 11, 2021): 28–35. http://dx.doi.org/10.17073/0021-3438-2021-1-28-35.

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It is proposed to use a spent cracking catalyst of petroleum hydrocarbons containing 1 wt.% of rare earth element (REE) oxides as an alternative REE feed source. The study covers the process of removing silicon in the form of ammonium hexafluorosilicate (NH4)2SiF6 by sintering an oil cracking catalyst sample with NH4F and subsequent (NH4)2SiF6 sublimation to produce an aluminum-containing concentrate of rare earth elements. The orthogonal central compositional planning of the experiment was used to study the effect of three factors: sublimation temperature (350 to 400 °С), duration (40 to 80 min), and weight of the catalyst fluorinated sintered mass (5 to 10 g) on the (NH4)2SiF6 sublimation completeness. Results obtained in the experiment were used to build a second-order model, which correlate with experimental data. The dynamics of (NH4)2SiF6 sublimation removal was determined for sublimation durations of τ = 10, 20, 40 and 80 min at processing temperatures of 350, 375 and 400 °C. The (NH4)2SiF6 removal degree values calculated based on the second-order model for τ = 44, 48, 52, 56, 60, 64, 68, 72, and 76 min fit well the experimental curves. Spectra of fluorinated catalyst samples before and after sublimation were studied using X-ray phase analysis and IR spectroscopy. The data of IR spectroscopy and X-ray phase analysis are in good agreement and show that (NH4)2SiF6, (NH4)3AlF6 and unreacted NH4F are present in the catalyst with NH4F sintered mass, and only aluminum compounds are detected – NH4AlF4 and AlF3 after sublimation. These data indicate the completeness of the sublimation removal of silicon from the catalyst and NH4F sintered mass with NH4AlF4 and AlF3 aluminum compounds only observed after sublimation. REE concentration is 15 % due to silicon removal.
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46

Kunimura, Shinsuke, and Jun Kawai. "Handy waveguide TXRF spectrometer for nanogram sensitivity." Powder Diffraction 23, no. 2 (June 2008): 146–49. http://dx.doi.org/10.1154/1.2919826.

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A specimen containing nanograms of sulfur, calcium, and 3d transition metal elements was measured by incident X-ray beams of various sizes restricted by a waveguide placed in a portable TXRF spectrometer. The signal to background ratios of spectra decreased with an increase in incident X-ray beam size. The portable spectrometer was also applied to rainwater and a specimen containing antimony and rare earth elements. Nanograms of elements in these specimens were detected by K-line or L-line excitation.
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47

Kong, Kai, Hai Xia Zhang, Huan Huan Li, Juan Pang, Ying Nan Chen, Yuan Li, Xue Mei Lin, Hai Bin Chu, and Yong Liang Zhao. "Synthesis and Luminescent Properties of Doped Europium Complexes with 2, 3 - Pyrazine Dicarboxylate." Advanced Materials Research 476-478 (February 2012): 1202–5. http://dx.doi.org/10.4028/www.scientific.net/amr.476-478.1202.

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Eleven europium complexes doped other metal ions with 2,3 - pyrazine dicarboxylic acid had been synthesized and characterized by elemental analyses, rare earth EDTA titration, IR, UV and fluorescence spectra. They were EuL1.5•5H2O, Eu0.5Ln0.5 L1.5•5H2O (Ln3+=La3+, Y3+, Gd3+), EuML2.5•8H2O (M2+= Mg2+, Ca2+, Sr2+, Ba2+, Co2+, Ni2+, Zn2+). Doped metal ions could enhanced the fluorescence of Eu3+ complex, and the order of the fluorescence enhancement was Zn2+>La3+>Gd3+>Y3+; Mg2+> Sr2+>Ca2+>Ba2+. And doped with Co2+ and Ni2+ made the Eu3+ luminescence quenched, which the luminous intensity was almost zero.
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48

Shamsutdinova, Medina Humaidovna, Zara Sultanovna Ilkhaeva, and Alet Ilyasovna Khasaeva. "SYNTHESIS, STRUCTURE AND PROPERTIES OF COMPLEX COMPOUNDS OF ANTHANOIDS WITH 4 - [(3,4-DIMETOXYBENZYL) AMINO] BENZOIC ACID." EurasianUnionScientists 6, no. 7(76) (August 20, 2020): 28–31. http://dx.doi.org/10.31618/esu.2413-9335.2020.6.76.940.

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The synthesis of complex compounds of 4 - [(3,4-dimethoxybenzyl) amino] benzoic acid (HL) with ions of samarium (III), europium (III), terbium (III), gadolinium (III) and dysprosium (III). According to the data of elemental analysis and thermogravimetry, the obtained complexes are hydrates of the composition LnL3 · nH2O, where n = 0-2. The area of their thermal stability is in the range from 100 ° С to 150 ° С. Electronic and infrared absorption spectra of the ligand and complexes with rare-earth metal ions have been measured. According to the IR spectra, the coordination of the ligand with the metal ion occurs at the carboxyl group. The carboxyl group is bidentate coordinated. To excite luminescence, a line of a mercury lamp with a wavelength of 248 nm was used. The highest luminescence intensity is observed for the coordination compounds Eu3 +, Tb3 +, Sm3 +, and Dy3 +.
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49

Shamsutdinova, M., and F. Dzhebirkhanova. "COMPLEX COMPOUNDS OF LANTANOIDS WITH 4 - [(2,4-DIMETOXYBENZYL) AMINO] BENZOIC ACID." National Association of Scientists 2, no. 68 (July 1, 2021): 57–60. http://dx.doi.org/10.31618/nas.2413-5291.2021.2.68.454.

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Abstract:
The synthesis of complex compounds of 4 - [(2,4-dimethoxybenzyl) amino] benzoic acid (HL) with ions of samarium (III), europium (III), terbium (III), gadolinium (III) and dysprosium (III). According to the data of elemental analysis and thermogravimetry, the obtained complexes are hydrates of the composition LnL3 · nH2O, where n = 0-2. The area of their thermal stability is in the range from 100 ° С to 150 ° С. Electronic and infrared absorption spectra of the ligand and complexes with rare-earth metal ions have been measured. According to the IR spectra, the coordination of the ligand with the metal ion occurs at the carboxyl group. The carboxyl group is bidentate coordinated. To excite luminescence, a line of a mercury lamp with a wavelength of 248 nm was used. The highest luminescence intensity is observed for the coordination compounds Eu3 +, Tb3 +, Sm3 +, and Dy3 +.
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50

Abou-Salem, L. I., K. E. Abdelmageed, I. A. Elmashad, and R. Al Allam. "Testing the core-cluster model calculations for some heavy deformed nuclei." International Journal of Modern Physics E 28, no. 07 (July 2019): 1950049. http://dx.doi.org/10.1142/s0218301319500496.

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Abstract:
In this work, the spectra of some even–even isotopes are studied by selecting core-cluster decomposition of the parent nucleus. The considered nuclei lie in the rare-earth and the transition metal regions. The Schrödinger equation can be solved using Bohr–Sommerfeld relation and the modified Woods–Saxon beside Coulomb potentials to reproduce the spectra of these isotopes with mass number [Formula: see text]. The theoretical calculations of the excitation energies of the ground state rotational band are compared to the experimental data. The cluster model calculations show a good agreement with the experimental data for the transitional and rotational nuclei more than the vibrational nuclei. Some negative parity bands of the chosen nuclei are studied. The core-cluster charge products are correlated with the transition probability [Formula: see text].
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