Observation of a phase transition in ThBr/sub 4/ and ThCl/sub 4/ single crystals by far-infrared and Raman spectroscopy study

Journal Article · Thu Jan 01 04:00:00 EST 1981 · J. Solid State Chem.; (United States)

DOI:https://doi.org/10.1016/0022-4596(81)90189-4· OSTI ID:6340994

Hubert, S ^[1]; Delamoye, P; Lefrant, S; Lepostollec, M; Hussonnois, M

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1. Institut de Physique Nucleaire, Orsay, France

At 4 K the visible and infrared absorption and emission spectra of U/sup 4 +/ in ThBr/sub 4/ and ThCl/sub 4/ single crystals are not very consistent with what is predicted by the selection rules for the room temperature structure. Thus we investigated Raman scattering in the temperature range 10 to 300 K to look for a structure change and obtain a better understanding of the spectroscopy of U/sup 4 +/ in ThBr/sub 4/ and ThCl/sub 4/. At room temperature, the observed Raman lines have been assigned on the basis of a D/sub 4h/ factor group analysis. The study of the temperature dependence of the Raman spectra permitted us to discover phase transitions of ThBr/sub 4/ and ThCl/sub 4/ at 95 and 70 k, respectively. The splitting observed for the strongest E/sub g/ symmetry mode shows a lowering of the symmetry below the transition point. Powder x-ray diffraction at 77 K of hygroscopic ThBr/sub 4/ is being carried out to determine the low-temperature structure. 8 figures, 4 tables.

• OSTI ID: 6340994
• Journal Information: J. Solid State Chem.; (United States), Journal Name: J. Solid State Chem.; (United States) Vol. 36:1; ISSN JSSCB
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400702* -- Radiochemistry & Nuclear Chemistry-- Properties of Radioactive Materials
ACTINIDE COMPOUNDS
BROMIDES
BROMINE COMPOUNDS
CHARGED PARTICLES
CHLORIDES
CHLORINE COMPOUNDS
CRYSTALS
DATA
EXPERIMENTAL DATA
HALIDES
HALOGEN COMPOUNDS
INFORMATION
INFRARED SPECTRA
IONS
LOW TEMPERATURE
MEDIUM TEMPERATURE
MONOCRYSTALS
NUMERICAL DATA
PHASE TRANSFORMATIONS
RAMAN SPECTRA
SPECTRA
TEMPERATURE DEPENDENCE
THORIUM BROMIDES
THORIUM CHLORIDES
THORIUM COMPOUNDS
ULTRALOW TEMPERATURE
URANIUM IONS