Znucalite, the only known zinc uranyl carbonate: Its crystal
structure and environmental implications

J 2024

Znucalite, the only known zinc uranyl carbonate: Its crystal structure and environmental implications

STECIUK, Gwladys; Juraj MAJZLAN; Jan ROHLICEK; Radek ŠKODA; Jiri SEJKORA et. al.

Základní údaje

Originální název

Znucalite, the only known zinc uranyl carbonate: Its crystal structure and environmental implications

Autoři

STECIUK, Gwladys; Juraj MAJZLAN; Jan ROHLICEK; Radek ŠKODA; Jiri SEJKORA a Jakub PLASIL

Vydání

American Mineralogist, Mineralogical Society of America, 2024, 0003-004X

Další údaje

Jazyk

angličtina

Typ výsledku

Článek v odborném periodiku

Obor

10504 Mineralogy

Stát vydavatele

Spojené státy

Utajení

není předmětem státního či obchodního tajemství

Odkazy

URL

Impakt faktor

Impact factor: 2.300

Kód RIV

RIV/00216224:14310/24:00138750

Organizační jednotka

Přírodovědecká fakulta

DOI

https://doi.org/10.2138/am-2023-8956

UT WoS

001245532900010

EID Scopus

2-s2.0-85192442613

Klíčová slova anglicky

Znucalite; uranyl carbonate; crystal structure; 3D electron diffraction; Rietveld refinement; conditions of formation; uranium immobilization

Štítky

14315010, rivok

Příznaky

Mezinárodní význam, Recenzováno

Změněno: 31. 1. 2025 18:09, Mgr. Marie Novosadová Šípková, DiS.

Anotace

V originále

Znucalite is a zinc uranyl-carbonate mineral that was until recently only partially characterized with a formula originally given as Zn12Ca(UO2)(CO3)(3)(OH)(22)4H(2)O, with an unknown crystal structure and ambiguous symmetry determinations. We have reinvestigated this mineral using three-dimensional electron diffraction (3D ED) and powder X-ray diffraction and revealed for the first time its structural details. Znucalite is unambiguously monoclinic, P21/m, with a = 10.722(2) & Aring;, b = 6.259(1) & Aring;, c = 25.355(1) & Aring;, beta = 101.13(1)degrees, and V = 1669.54(9) & Aring;(3). The structure refinement of the 3D ED data using the dynamical approach (Robs = 0.1594 for 3579 observed reflections and 244 parameters) provided the following structure model. Znucalite possesses a layered structure, with a [Zn-10(OH)(14)(CO3)(2)] double sheet (with Zn2+ both in octahedra and tetrahedra), which is connected to a thick interlayer that hosts U6+, Ca2+, and H2O molecules. The linkage between structural units and the interlayer occurs via the vertices of ZnO4 tetrahedra protruding from the sheet. In the interlayer, differences in ordering between U and Ca take place and likely cause the difficulties encountered during the attempts to solve the structure. The refined structural formula of znucalite, Zn10Ca0.828[UO2](0.828)[CO3](4)(OH)(15.312)(H2O)(5.484), corresponds well to the composition obtained from the electron-microprobe analyses, (Zn9.84Al0.16)(Sigma 10.00) Ca-0.83(UO2)(0.80)[(CO3)(3.96)(SO4)(0.04)](Sigma 4.00)(OH)(15.42)(H2O)(5.48). Raman spectroscopy evidenced the presence of several non-equivalent CO3 groups, as well as OH and H2O. The U-O bond lengths obtained from the stretching frequencies of UO22+ vibrations are in line with the structural model. A discussion on the environmental importance of znucalite is appended, based on geochemical calculations with an estimate of the solubility product for this mineral.

Návaznosti

EF16_026/0008459, projekt VaV

Název: Dlouhodobý výzkum geochemických bariér pro ukládání jaderného odpadu

90251, velká výzkumná infrastruktura

Název: CzechNanoLab II

Citovat

STECIUK, Gwladys; Juraj MAJZLAN; Jan ROHLICEK; Radek ŠKODA; Jiri SEJKORA a Jakub PLASIL. Znucalite, the only known zinc uranyl carbonate: Its crystal structure and environmental implications. American Mineralogist. Mineralogical Society of America, 2024, roč. 109, č. 5, s. 949-959. ISSN 0003-004X. Dostupné z: https://doi.org/10.2138/am-2023-8956.

@article{2473059,
   author = {Steciuk, Gwladys and Majzlan, Juraj and Rohlicek, Jan and Škoda, Radek and Sejkora, Jiri and Plasil, Jakub},
   article_number = {5},
   doi = {https://doi.org/10.2138/am-2023-8956},
   keywords = {Znucalite; uranyl carbonate; crystal structure; 3D electron diffraction; Rietveld refinement; conditions of formation; uranium immobilization},
   language = {eng},
   issn = {0003-004X},
   journal = {American Mineralogist},
   title = {Znucalite, the only known zinc uranyl carbonate: Its crystal structure and environmental implications},
   url = {https://doi.org/10.2138/am-2023-8956},
   volume = {109},
   year = {2024}
}

TY  - JOUR
ID  - 2473059
AU  - Steciuk, Gwladys - Majzlan, Juraj - Rohlicek, Jan - Škoda, Radek - Sejkora, Jiri - Plasil, Jakub
PY  - 2024
TI  - Znucalite, the only known zinc uranyl carbonate: Its crystal structure and environmental implications
JF  - American Mineralogist
VL  - 109
IS  - 5
SP  - 949-959
EP  - 949-959
PB  - Mineralogical Society of America
SN  - 0003004X
KW  - Znucalite
KW  - uranyl carbonate
KW  - crystal structure
KW  - 3D electron diffraction
KW  - Rietveld refinement
KW  - conditions of formation
KW  - uranium immobilization
UR  - https://doi.org/10.2138/am-2023-8956
N2  - Znucalite is a zinc uranyl-carbonate mineral that was until recently only partially characterized with a formula originally given as Zn12Ca(UO2)(CO3)(3)(OH)(22)4H(2)O, with an unknown crystal structure and ambiguous symmetry determinations. We have reinvestigated this mineral using three-dimensional electron diffraction (3D ED) and powder X-ray diffraction and revealed for the first time its structural details. Znucalite is unambiguously monoclinic, P21/m, with a = 10.722(2) & Aring;, b = 6.259(1) & Aring;, c = 25.355(1) & Aring;, beta = 101.13(1)degrees, and V = 1669.54(9) & Aring;(3). The structure refinement of the 3D ED data using the dynamical approach (Robs = 0.1594 for 3579 observed reflections and 244 parameters) provided the following structure model. Znucalite possesses a layered structure, with a [Zn-10(OH)(14)(CO3)(2)] double sheet (with Zn2+ both in octahedra and tetrahedra), which is connected to a thick interlayer that hosts U6+, Ca2+, and H2O molecules. The linkage between structural units and the interlayer occurs via the vertices of ZnO4 tetrahedra protruding from the sheet. In the interlayer, differences in ordering between U and Ca take place and likely cause the difficulties encountered during the attempts to solve the structure. The refined structural formula of znucalite, Zn10Ca0.828[UO2](0.828)[CO3](4)(OH)(15.312)(H2O)(5.484), corresponds well to the composition obtained from the electron-microprobe analyses, (Zn9.84Al0.16)(Sigma 10.00) Ca-0.83(UO2)(0.80)[(CO3)(3.96)(SO4)(0.04)](Sigma 4.00)(OH)(15.42)(H2O)(5.48). Raman spectroscopy evidenced the presence of several non-equivalent CO3 groups, as well as OH and H2O. The U-O bond lengths obtained from the stretching frequencies of UO22+ vibrations are in line with the structural model. A discussion on the environmental importance of znucalite is appended, based on geochemical calculations with an estimate of the solubility product for this mineral.
ER  -

STECIUK, Gwladys; Juraj MAJZLAN; Jan ROHLICEK; Radek ŠKODA; Jiri SEJKORA a Jakub PLASIL. Znucalite, the only known zinc uranyl carbonate: Its crystal structure and environmental implications. \textit{American Mineralogist}. Mineralogical Society of America, 2024, roč.~109, č.~5, s.~949-959. ISSN~0003-004X. Dostupné z: https://doi.org/10.2138/am-2023-8956.

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