2024 - Sustainable Industrial Processing Summit
SIPS 2024 Volume 16. Intl. Symp on Electrochemistry, Molten Salts, Corrosion, Recycling and Battery
| Editors: | F. Kongoli, C.A. Amatore, R. Fehrmann, G. Kipouros, I. Paspaliaris, G. Saevarsdottir, R. Singh, R. Gupta, M. Halama, D. Macdonald, F. Wang, M. Barinova, F. Ahmed, C. Gaidau, X. Guo, K. Kolomaznik, H. Ozgunay, K. Tang, N.N. Thanh, S. Yefremova, K. Aifantis, Z. Bakenov, C. Capiglia, V. Kumar, A. U. H. Qurashi, A. Tressaud, R. Yazami |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2024 |
| Pages: | 243 pages |
| ISBN: | 978-1-998384-34-1 (CD) |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
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f – d TRANSITIONS IN TbCl3 AND CeCl3 ELECTRONIC SPECTRA IN CHLORIDE MELTS
Alexei Potapov1; Alexander Salyulev1;1INSTITUTE OF HIGH TEMPERATURE ELECTROCHEMISTRY, Ekaterinburg, Russian Federation;
Type of Paper: Regular
Id Paper: 289
Topic: 13
Abstract:
Electronic absorption spectra (EAS) of rare earth ions in melts are scantily known. Since 4f electrons spend most of their time very near the nucleus, thee are well shielded by all the other electrons of a lanthanide ion from the influence of the crystalline fields of surrounding ligands. This circumstance, coupled with the fact that the spin-orbit interaction is about ten times larger for 4f than 3d electrons, makes the spectra of 4f ions much less sensitive to environmental changes than those of d-ions. However, spectra of the several 4f-cations (Ce(III), Pr(III), Tb(III)) contain not only orbitally-forbidden f↔f transitions, but also 4fn↔4fn-15d1 allowed ones. These transitions are almost unexplored. Only very scant data on Ce(III) available [1].
EAS of CeCl3 and TbCl3 dilute solutions was recorded in molten NaCl, NaCl-KCl (1:1), KCl and CsCl over the range 40000 to 8000 cm-1. Quartz 2 mm pathlength cells were used for measurements, temperature region was from 700 (800) up to 1000 0C. Concentrations were about 0.005 mol/l (near 0.03 mol %) in case of CeCl3 and essentially higher ~0.5 mol/l (~2 mol %) for TbCl3. By way of example EAS of CeCl3 and TbCl3 in molten NaCl-KCl consist of one weakly asymmetrical band with maximum near 31000 and 37000 cm-1 respectively. This band is 2 to 3 times narrower than the electron-transfer bands. In contrast to f↔f transitions intensity of these bands diminishes as temperature is rises, and rises in the row of the solvents from NaCl to CsCl. However, oscillator strength reduces only slightly with essential increasing of temperature. These changes are result of surroundings influence upon d-sublevel only. By mathematical analysis it was shown band observed consists of two ones. All available data are well compatible with octahedral melt structure – CeCl63- and TbCl63- complex formation.