The use of Raman and TRLF spectroscopy for differentiating early stage alteration products of spent nuclear fuel

Frankland, Victoria L.; Milodowski, Antoni E.; Bright, Joshua William George; Read, David

doi:10.1016/j.apgeochem.2021.104934

Cited by 6 publications

(5 citation statements)

References 59 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A k U-O value of 5.63 ± 0.08 millidynes Å −1 was obtained with the error calculated from the variation in the ν 1 (UO 2 ) 2+ mode peak position. To the best of our knowledge, k U-O has not been calculated for johannite previously; however, similar values have been reported for uranyl oxyhydroxides [42,44], carbonates [60], phosphates [30,45,53], and silicates [43].…”

Section: Assignmentsupporting

confidence: 75%

“…Similarly, the excitation peak at 502.7 nm was coincident (within experimental error), with the emission peak at 501.3 nm. No luminescence excitation spectra have been published previously for johannite, but similar peak positions have been reported for Sr-rich meta-autunite ((Ca,Sr)(UO 2 ) 2 (PO 4 ) 2 •2-8H 2 O [30]), boltwoodite (K,Na(UO 2 )SiO 3 OH•1.5H 2 O [42]), uranophane (Ca(UO 2 ) 2 (SiO 3 OH) 2 •5H 2 O [43]), and vandendriesscheite (Pb 1.5 (UO 2 ) 10 O 6 (OH) 11 •11H 2 O [42]), suggesting that the uranyl ion exhibits common multiple excitation features.…”

Section: Luminescence Spectroscopysupporting

confidence: 63%

“…The variation in the band spacing value obtained in this study and the reported equivalent ν 1 (UO 2 ) 2+ modal position is unclear. Previous luminescence studies suggest better agreement was obtained with very well-defined emission peaks [42,43], suggesting the band spacing value can only be reliably obtained from those specimens that emit intense luminescence, unlike johannite. studies on johannite luminescence in the literature.…”

Section: Luminescence Spectroscopymentioning

confidence: 87%

“…It is well-known that chemical structure information can be extracted from Raman spectra; however, this technique is prone to luminescence effects masking, either wholly or partly, the Raman transitions [29,30,42,44,[51][52][53]. Whilst it is essential to choose a laser wavelength that minimizes luminescence masking, the ability to obtain Raman spectra using multiple lasers enables different regions of a specimen to be probed as the laser wavelength and energy will govern the penetration depth into the specimen; a potential benefit when distinguishing between thin films and bulk substrates.…”

Section: Raman Spectroscopymentioning

confidence: 99%

See 3 more Smart Citations

Laser-Based Characterisation of the Copper Uranyl Sulphate, Johannite

2022

Self Cite

View full text Add to dashboard Cite

Uranyl sulphate minerals are common alteration phases in uranium mines and uraniferous waste deposits where they occur in conjunction with other products of acidic drainage such as jarosite. Although not persistent in nature due to their high solubility, they may play an important role in governing uranium mobility during the operational and immediate post-closure environment of an engineered radioactive waste repository where oxidising conditions prevail. One such mineral, johannite (Cu(UO2)2(SO4)2(OH)2·8H2O), is of particular interest given the stated intention of several countries to use copper canisters in the disposal of spent nuclear fuel. A museum reference sample of johannite has been characterised by luminescence and multiple-laser Raman spectroscopy, resulting in the first reported luminescence excitation and emission spectra for this mineral. Well-defined Raman features were observed using 785, 633, and 532 nm lasers with the resolved peaks corresponding well to the published spectra. The Raman spectrum measured with the 457 nm laser was mostly masked by a series of repeating doublets attributed to the luminescence emission features, from which band spacing values of 831 and 823 cm−1 were extracted; the former corresponded to both the resolved 785 nm ν1(UO2)2+ peak position and the band spacing value obtained from the first reported luminescence emission spectrum for johannite. Four emission and nine excitation peaks were resolved from the luminescence spectra. The findings indicate that a suite of complementary laser-based techniques offer the potential for real-time characterisation of johannite formed in environments where intrusive sampling, transportation, and ‘off-site’ laboratory analysis are not feasible.

show abstract

Section: Assignmentsupporting

confidence: 75%

Section: Luminescence Spectroscopysupporting

confidence: 63%

Section: Luminescence Spectroscopymentioning

confidence: 87%

Section: Raman Spectroscopymentioning

confidence: 99%

See 2 more Smart Citations

Laser-Based Characterisation of the Copper Uranyl Sulphate, Johannite

2022

Self Cite

View full text Add to dashboard Cite

show abstract

“…Further methodology has been proposed for environmental monitoring in the context of waste management and remediation of possibly contaminated sites (e.g. DeNeufville et Meinrath et al 2003;Nelson 2009;Arnold et al 2011;Frankland et al 2021).…”

Section: Introductionmentioning

confidence: 99%

Spectral variability of the uranyl silicates uranophane-α and uranophane-β: polymorphism and luminescence

Stärk¹,

Noller²

2022

Phys Chem Minerals

View full text Add to dashboard Cite

The luminescence of the uranyl cation UO22+ depends on the local crystalline environment and is sensitive to structural influences. Steady-state photoluminescence emission spectra of the related uranyl silicates uranophane-α, uranophane-β, sklodowskite and haiweeite from various locations are presented and discussed in the light of structure–property relation. The four mineral species were chosen for their close relationships: uranophane-α and uranophane-β are polymorphs and share the underlaying topology with sklodowskite. Haiweeite, with different topology, shares the composing elements Ca, U, Si, O with uranophane, while in sklodowskite Mg replaces Ca. All species show some variability in their spectra, parameterized as a variation of the centroid wavelength. Those variations are linked to defects and structural disorder, relevant in studies of uranyl speciation and migration. We present empiric spectra of the four mineral species with the least influence of structural disorder. As an unexpected feature, a prominent—partly dominating—double peak structure occurs in the case of uranophane-α only, while it is absent in the spectra of the other species. Considering a model of luminescent transitions in the uranyl ion in more detail, this observation is discussed in the light of the polymorphism of uranophane. We show evidence that variable amounts of uranophane-β phase embedded in uranophane-α are possibly at the origin of this spectral signature. Growth of those uranophane-β clusters might be induced by defects in the uranophane-α lattice and further promoted by the polymorphism of uranophane.

show abstract