KSeries X-Ray Wavelengths in Rare Earth Elements

1958 ◽  
Vol 112 (4) ◽  
pp. 1183-1186 ◽  
Author(s):  
E. L. Chupp ◽  
J. W. M. Du Mond ◽  
F. J. Gordon ◽  
R. C. Jopson ◽  
Hans Mark
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
X Ray

Structure Maps and Phase Stability in AlTi3 Alloyed with Rare-Earth Elements

1988 ◽  
Vol 133 ◽  
Author(s):  
C. T. Liu ◽  
J. A. Horton ◽  
D. G. Petitifor
Keyword(s):  
Crystal Structure ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Solubility Limit ◽  
Size Factor ◽  
X Ray Diffraction ◽  
Atomic Size ◽  
X Ray ◽  
Dependent Parameter ◽  
Rare Earth Additions

ABSTRACTRare-earth elements including Y, Er and Sc were added to AlTi3 for stabilizing the Ll2 ordered crystal structure, as predicted by the AB3 structure map. The crystal structure and phase composition in the AlTi3 alloys were studied by electron microprobe analysis, X-ray diffraction and TEM. The solubility limit of the rare-earth elements were determined and correlated with the atomic size factor. The results obtained so far indicate that rare-earth additions are unable to change the crystal structure of AlTi3 from DO19 to Ll2. The inability to stabilize the Ll2 structure demonstrates the need to characterize the structure map domains with a further period-dependent parameter.

Affinity of dual energy X-ray transmission sensors on minerals bearing heavy rare earth elements

2020 ◽  
Vol 147 ◽  
pp. 106151 ◽  
Author(s):  
Moacir Medeiros Veras ◽  
Aaron Samuel Young ◽  
Cristiano Rocha Born ◽  
Artur Szewczuk ◽  
Artur Cezar Bastos Neto ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Dual Energy ◽  
Heavy Rare Earth ◽  
X Ray ◽  
Heavy Rare Earth Elements

scholarly journals Hydrothermal Synthesis of Rare-Earth Modified Titania: Influence on Phase Composition, Optical Properties, and Photocatalytic Activity

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 713 ◽  
Author(s):  
Nejc Rozman ◽  
David Tobaldi ◽  
Uroš Cvelbar ◽  
Harinarayanan Puliyalil ◽  
João Labrincha ◽  
...  
Keyword(s):  
Optical Properties ◽  
Photocatalytic Activity ◽  
Rare Earth ◽  
Hydrothermal Synthesis ◽  
Rare Earth Elements ◽  
Rare Earths ◽  
Light Absorption ◽  
Pure Tio2 ◽  
X Ray ◽  
Hydroxyl Oxygen

In order to expand the use of titania indoor as well as to increase its overall performance, narrowing the band gap is one of the possibilities to achieve this. Modifying with rare earths (REs) has been relatively unexplored, especially the modification of rutile with rare earth cations. The aim of this study was to find the influence of the modification of TiO2 with rare earths on its structural, optical, morphological, and photocatalytic properties. Titania was synthesized using TiOSO4 as the source of titanium via hydrothermal synthesis procedure at low temperature (200 °C) and modified with selected rare earth elements, namely, Ce, La, and Gd. Structural properties of samples were determined by X-ray powder diffraction (XRD), and the phase ratio was calculated using the Rietveld method. Optical properties were analyzed by ultraviolet and visible light (UV-Vis) spectroscopy. Field emission scanning electron microscope (FE-SEM) was used to determine the morphological properties of samples and to estimate the size of primary crystals. X-ray photoelectron spectroscopy (XPS) was used to determine the chemical bonding properties of samples. Photocatalytic activity of the prepared photocatalysts as well as the titania available on the market (P25) was measured in three different setups, assessing volatile organic compound (VOC) degradation, NOx abatement, and water purification. It was found out that modification with rare earth elements slows down the transformation of anatase and brookite to rutile. Whereas the unmodified sample was composed of only rutile, La- and Gd-modified samples contained anatase and rutile, and Ce-modified samples consisted of anatase, brookite, and rutile. Modification with rare earth metals has turned out to be detrimental to photocatalytic activity. In all cases, pure TiO2 outperformed the modified samples. Cerium-modified TiO2 was the least active sample, despite having a light absorption tail up to 585 nm wavelength. La- and Gd-modified samples did not show a significant shift in light absorption when compared to the pure TiO2 sample. The reason for the lower activity of modified samples was attributed to a greater Ti3+/Ti4+ ratio and a large amount of hydroxyl oxygen found in pure TiO2. All the modified samples had a smaller Ti3+/Ti4+ ratio and less hydroxyl oxygen.

Multiplet structure in X-ray photoelectron spectra of rare earth elements and their surface oxides

1975 ◽  
Vol 60 ◽  
pp. 37 ◽  
Author(s):  
W. C. Lang ◽  
B. D. Padalia ◽  
L. M. Watson ◽  
D. J. Fabian ◽  
P. R. Norris
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Photoelectron Spectra ◽  
Multiplet Structure ◽  
X Ray ◽  
Surface Oxides

A Rapid and Accurate X-Ray Determination of the Rare Earths Elements in Solid or Liquid Materials using the Double Dilution Method

1968 ◽  
Vol 12 ◽  
pp. 546-562
Author(s):  
R. Tertian
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Accurate Determination ◽  
Fluorescence Analysis ◽  
Dilution Method ◽  
Practical Advantage ◽  
X Ray ◽  
The Matrix

AbstractThe double dilution method has many important advantages. For any element to be determined, let us say A, It enables us to control or calculate the matrix factor (sum of the absorption end enhancement effects) for the sample being Investigated towards A radiation, and it furnishes corrected Intensities which are strictly proportional to A concentration. Thus the results are exact, whatever the general composition of the sample, their accuracy depending only on the quality of measurement and preparation. Another major practical advantage is that the method does not require systematic calibration but only a few permanent standards consisting of a pure compound or of an accurately known sample.The procedure has been tested successfully for accurate determination of rare earth elements using, for solid materials such as ores and oxide mixtures, the borax fusion technique. It also can be readily applied to liquids. All the rare earth elements can be titrated by that method, as well as yttrium, thorium and, if necessary, all the elements relevant to X-ray fluorescence analysis. The concentration range considered for solids is of one comprised between 0.5 and 100 % and, with a lesser accuracy, between 0.1 and 0-5 % Examples are given relative to the analysis of various ores. Finally it rcust be pointed out that the method is universal and applies to the analysis of every solid, especially ores, provided that they can be converted to solid or liquid solutions. It appears that most industrial analyses can be worked on In this way.

scholarly journals Concentration of Rare Earth Elements (Sc, Y, La, Ce, Nd, Sm) in Bauxite Residue (Red Mud) Obtained by Water and Alkali Leaching of Bauxite Sintering Dust

Minerals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 500 ◽  
Author(s):  
Leonid Chaikin ◽  
Andrei Shoppert ◽  
Dmitry Valeev ◽  
Irina Loginova ◽  
Julia Napol’skikh
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Red Mud ◽  
Electrostatic Precipitator ◽  
Bauxite Residue ◽  
X Ray ◽  
Before And After ◽  
Shrinking Core ◽  
Alkali Leaching ◽  
Rotary Kilns

One of the potential sources of rare-earth elements (REE) is the industrial waste known as red mud (bauxite residue), in which the majority of REE from the initial bauxite are concentrated via the Bayer process. Therefore, the studies of the subject, both in Russia and outside, focus almost exclusively on red mud processing. This article looks into the possibility of REE concentration into red mud by leaching an intermediate product of the bauxite sintering process at Russian alumina refineries, namely electrostatic precipitator (ESP) dust. The experimental works were performed by X-ray diffraction (XRD)and electron probe microanalysis (EPMA) of the sinter and sinter dust. The determination of major and rare-earth elements in the sinter from the rotary kilns and in the ESP dust before and after leaching was carried out by X-ray fluorescence (XRF) and plasma mass spectrometry (ICP-MS). The study showed that it is possible to obtain red mud that contains three times more REE than traditional waste red mud after two-stage leaching ESP dust in the water at 95 °C followed by leaching in an alkaline-aluminate liquor at 240 °C. The shrinking core model was used to study the kinetics of leaching of the original ESP dust and water-treated dust in alkaline-aluminate liquor. The study showed the change in the limiting stage of the alkaline leaching process after water treatment, with the activation energy growing from 24.98 to 33.19 kJ/mol.

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