title: Кристаллохимия высоконатриевого чильманита-(Cе) (Хибинский массив, Кольский полуостров) // ЗРМО.
metadata.name: dc.date.accessioned
metadata.value: 2020-09-09T07:34:41Z
metadata.lang: -
metadata.name: dc.date.available
metadata.value: 2020-09-09T07:34:41Z
metadata.lang: -
metadata.name: dc.date.issued
metadata.value: 2017
metadata.lang: -
metadata.name: dc.identifier.uri
metadata.value: http://hdl.handle.net/11701/19311
metadata.lang: -
metadata.name: dc.description.abstract
metadata.value: Chemical composition, crystal structure, and Raman spectrum have been investigated for the
  Na-rich kihlmanite-(Ce). Chemical composition of this mineral: Na2Î 4.83, SiO2 9.76, CaO 0.94,
  TiO2 11.74, Nb2O5 1.83, La2O3 10.63, Ce2O3 26.22, Pr2O3 2.23, Nd2O3 9.00, Sm2O3 1.30, CO2 14.40,
  H2O 6.00, corresponds to empirical formula: (Na0.95Ca0.11)1.06(Ce0.98La0.40Nd0.33Pr0.08Sm0.05)1.85
   
  (Ti0.91Nb0.08)0.99O2[Si1.00O4] {(HCO3)1.24(ÑÎ3)0.76}2
   Í2O. Raman spectrum contains following lines:
  850, 722, (n3, Si—O) 564, 610, 424 (n2, n4, Si-O), 1069, 919, 964 (n1, CO3, HCO3), 675 (n4, CO3), 388
  (CaO6, NaO6), 290 (TiO6) cm–1. Crystal structure is refined in the space group P1 (a = 5.0005(3), b =
  = 7.5273(6), ñ = 15.3344(16) Å, a = 101.950(8), b = 92.938(7), g = 109.323(7)°) up to the value of
  crystallographic repeatability factor R1 = 0.054 for 1842 independent reflections (|Fo| > 4sF). Obtained
  crystal-chemical formula may be written as following: (Na1.10Ca0.11)1.21Ce2.00(Ti0.77Nb0.23)1.00
   
  O2.00 [Si1.00O4.00]{(CO3)1.55(HCO3)0.45}2.00
   H2O1.16. Na atoms occupy in the structure three independent
  positions: Na(l), Na(2) and Na(3). The presence of additional sodium site, relatively to the standard
  kihlmanite-(Ce), enforces chemical bonds between «tundrite» layers due to decrease of the unit
  cell parameter ñ by ~ 0.1 Å. Occurrence of sodium in the kihlmanite-(Ce) structure by the scheme:
  9 + = + + HOC Na CO 3
  –
  3
  2– leads to the dominance of CO3
  2– groups in hydrocarbonate position.
  Key words: kihlmanite-(Ce), Na-rich, crystal structure, Raman spectrum, Khibiny massif.
metadata.lang: en_GB
metadata.name: dc.title
metadata.value: Кристаллохимия высоконатриевого чильманита-(Cе) (Хибинский массив, Кольский полуостров) // ЗРМО.
metadata.lang: en_GB
resources.filename: 9.pdf
resources.url: https://dspace.spbu.ru/bitstream/11701/19311/1/9.pdf
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