On phosphorescence at very low temperatures

Becquerel, Henri; Becquerel, Jean; Onnes, H. Kamerlingh

doi:10.1007/978-94-009-2079-8_13

Cited by 5 publications

(7 citation statements)

References 1 publication

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“…For some of the minerals such as meta-torbernite, the spectra intensity was enhanced three to four orders of magnitude due to effective suppression of fluorescence quenching effects and spectral line broadening effects. Such spectral changes are consistent with the early observations of Becquerel et al [29], Pant and Khandelwal [30], Nichols and Howes [31], Samojlov [32], and Dieke and Duncan [33].…”

Section: Fluorescence Characteristics At 6 Ksupporting

confidence: 91%

A cryogenic fluorescence spectroscopic study of uranyl carbonate, phosphate and oxyhydroxide minerals

Wang¹,

Zachara

Liu

et al. 2008

Radiochimica Acta

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Uranium / Fluorescence / Cryogenic temperature / Time-resolved / Carbonate / PhosphateSummary. In this work we applied time-resolved laserinduced fluorescence spectroscopy (TRLIF) at both room temperature (RT) and near liquid-helium temperature (6 K) to characterize a series of natural and synthetic minerals of uranium carbonate, phosphate and oxyhydroxides including rutherfordine, zellerite, liebigite, phosphuranylite, meta-autunite, meta-torbernite, uranyl phosphate, sodiumuranyl-phosphate, becquerelite, schoepite, meta-schoepite, dehydrated schoepite and compreignacite, and have compared the spectral characteristics among these minerals as well as our previously published data on uranyl silicates. For the carbonate minerals, the fluorescence spectra of rutherfordine showed significant difference from those of zellerite and liebigite. The fluorescence spectra of the phosphate minerals closely resemble each other despite the differences in their composition and structure. For all uranium oxyhydroxides, the fluorescence spectra are largely red-shifted as compared to those of the uranium carbonates and phosphates and their vibronic bands are broad and less resolved at RT. The enhanced spectra resolution at 6 K allows more accurate determination of the fluorescence band origin and offers a complemental method to measure the O=U=O symmetrical stretch frequency, ν 1 , from the spacings of the vibronic bands of the fluorescence spectra. The average ν 1 values appear to be inversely correlated with the average pK a values of the anions.

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Section: Fluorescence Characteristics At 6 Ksupporting

confidence: 91%

A cryogenic fluorescence spectroscopic study of uranyl carbonate, phosphate and oxyhydroxide minerals

Wang¹,

Zachara

Liu

et al. 2008

Radiochimica Acta

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“…For uranyl compounds, the spectral intensity and resolution enhancement at lower temperatures was noticed as early as 1909 by Becquerel et al (1909Becquerel et al ( , 1910. They cooled solid uranyl salts to liquid air temperature (90 K), and observed the disappearance, splitting, and sharpening of spectral bands.…”

Section: Spectral Enhancement At Cryogenic Temperaturesmentioning

confidence: 90%

“…This band may originate from radiative transition from the second vibrational level (v ϭ 1) of the excited state to the ground state. The population of this excited vibrational level is negligible at lowered temperatures, causing the disappearance of the band (Becquerel et al, 1909(Becquerel et al, , 1910.…”

Section: Fluorescence Characteristics Of Uranium Silicate Mineralsmentioning

confidence: 97%

Fluorescence spectroscopy of U(VI)-silicates and U(VI)-contaminated Hanford sediment

Wang

Zachara

Gassman

et al. 2005

Geochimica et Cosmochimica Acta

148

134

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Time-resolved U(VI) laser fluorescence spectra (TRLFS) were recorded for a series of natural uranium-silicate minerals including boltwoodite, uranophane, soddyite, kasolite, sklodowskite, cuprosklodowskite, haiweeite, and weeksite, a synthetic boltwoodite, and four U(VI)-contaminated Hanford vadose zone sediments. Lowering the sample temperature from RT to ϳ 5.5 K significantly enhanced the fluorescence intensity and spectral resolution of both the minerals and sediments, offering improved possibilities for identifying uranyl species in environmental samples. At 5.5 K, all of the uranyl silicates showed unique, well-resolved fluorescence spectra. The symmetric O ϭ U ϭ O stretching frequency, as determined from the peak spacing of the vibronic bands in the emission spectra, were between 705 to 823 cm Ϫ1 for the uranyl silicates. These were lower than those reported for uranyl phosphate, carbonate, or oxy-hydroxides. The fluorescence emission spectra of all four sediment samples were similar to each other. Their spectra shifted minimally at different time delays or upon contact with basic Na/Ca-carbonate electrolyte solutions that dissolved up to 60% of the precipitated U(VI) pool. The well-resolved vibronic peaks in the fluorescence spectra of the sediments indicated that the major fluorescence species was a crystalline uranyl mineral phase, while the peak spacing of the vibronic bands pointed to the likely presence of uranyl silicate. Although an exact match was not found between the U(VI) fluorescence spectra of the sediments with that of any individual uranyl silicates, the major spectral characteristics indicated that the sediment U(VI) was a uranophane-type solid (uranophane, boltwoodite) or soddyite, as was concluded from microprobe, EXAFS, and solubility analyses.

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“…A consequence of these fluorescence studies was the discovery of radioactivity when a sample of K 2 UO 2 (SO 4 ) 2 was placed next to a covered photographic plate and the image of the sample was observed on the developed plate . J. Becquerel (petit-fils) collaborated with Kamerlingh Onnes in observing uranyl fluorescence spectra down to liquid hydrogen temperature …”

Section: Introductionmentioning

confidence: 99%

“…18 J. Becquerel (petit-fils) collaborated with Kamerlingh Onnes in observing uranyl fluorescence spectra down to liquid hydrogen temperature. 19 Up to 1940. From the 1870s on, many different research groups studied the spectroscopy of uranyl salts.…”

Section: Introductionmentioning

confidence: 99%

Application of Relativistic Quantum Chemistry to the Electronic Energy Levels of the Uranyl Ion

1999

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The ground and excited electronic states of the uranyl ion UO2 2+ are computed using relativistic core and spin−orbit potentials and multireference graphical unitary group approach configuration interaction as implemented in the COLUMBUS suite of programs. Excitation energies, symmetric stretch vibrational frequencies, and angular momentum coupling properties are compared to the extent possible with spectroscopic data from Cs2UO2Cl4 and CsUO2(NO3)3.

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On phosphorescence at very low temperatures

Cited by 5 publications

References 1 publication

A cryogenic fluorescence spectroscopic study of uranyl carbonate, phosphate and oxyhydroxide minerals

A cryogenic fluorescence spectroscopic study of uranyl carbonate, phosphate and oxyhydroxide minerals

Fluorescence spectroscopy of U(VI)-silicates and U(VI)-contaminated Hanford sediment

Application of Relativistic Quantum Chemistry to the Electronic Energy Levels of the Uranyl Ion

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