Crystal-Chemical Features of Apatite in Carbonatites of the Tomtor Deposit (The Republic of Sakha (Yakutia), Russia): X-Ray Diffraction and Vibrational Spectroscopy Data

2021 ◽  
Vol 66 (6) ◽  
pp. 923-930
Author(s):  
T. N. Moroz ◽  
N. A. Palchik ◽  
S. M. Zhmodik ◽  
V. A. Ponomarchuk ◽  
S. V. Goryainov
Keyword(s):  
Vibrational Spectroscopy ◽  
Crystal Chemical ◽  
Spectroscopy Data ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Republic

CRYSTAL-CHEMICAL REGULARITIES AND IDENTIFICATION CRITERIA IN Fe-BEARING, K-DIOCTAHEDRAL 1M MICAS FROM X-RAY DIFFRACTION AND INFRARED SPECTROSCOPY DATA

2017 ◽  
Vol 65 (4) ◽  
pp. 234-251 ◽  
Author(s):  
Bella B. Zviagina ◽  
Victor A. Drits ◽  
Boris A. Sakharov ◽  
Tatiana A. Ivanovskaya ◽  
Olga V. Dorzhieva ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Crystal Chemical ◽  
Spectroscopy Data ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals Crystal Chemical Relations in the Shchurovskyite Family: Synthesis and Crystal Structures of K2Cu[Cu3O]2(PO4)4 and K2.35Cu0.825[Cu3O]2(PO4)4

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 807
Author(s):  
Ilya V. Kornyakov ◽  
Sergey V. Krivovichev
Keyword(s):  
Crystal Structure ◽  
Crystal Structures ◽  
Structural Complexity ◽  
Crystal Chemical ◽  
X Ray Diffraction ◽  
Complexity Measures ◽  
X Ray ◽  
The Family ◽  
Similarities And Differences ◽  
Related Compounds

Single crystals of two novel shchurovskyite-related compounds, K2Cu[Cu3O]2(PO4)4 (1) and K2.35Cu0.825[Cu3O]2(PO4)4 (2), were synthesized by crystallization from gaseous phase and structurally characterized using single-crystal X-ray diffraction analysis. The crystal structures of both compounds are based upon similar Cu-based layers, formed by rods of the [O2Cu6] dimers of oxocentered (OCu4) tetrahedra. The topologies of the layers show both similarities and differences from the shchurovskyite-type layers. The layers are connected in different fashions via additional Cu atoms located in the interlayer, in contrast to shchurovskyite, where the layers are linked by Ca2+ cations. The structures of the shchurovskyite family are characterized using information-based structural complexity measures, which demonstrate that the crystal structure of 1 is the simplest one, whereas that of 2 is the most complex in the family.

Crystal-chemical aspects of the roméite group, A2Sb2O6Y, of the pyrochlore supergroup

2017 ◽  
Vol 81 (6) ◽  
pp. 1287-1302
Author(s):  
Ferdinando Bosi ◽  
Andrew G. Christy ◽  
Ulf Hålenius
Keyword(s):  
Microprobe Analysis ◽  
Electron Microprobe Analysis ◽  
Structural Parameters ◽  
Chemical Information ◽  
Crystal Chemical ◽  
X Ray Diffraction ◽  
Structural Variations ◽  
X Ray ◽  
End Members ◽  
Charge Balancing

AbstractFour specimens of the roméite-group minerals oxyplumboroméite and fluorcalcioroméite from the Långban Mn-Fe deposit in Central Sweden were structurally and chemically characterized by single-crystal X-ray diffraction, electron microprobe analysis and infrared spectroscopy. The data obtained and those on additional roméite samples from literature show that the main structural variations within the roméite group are related to variations in the content of Pb2+, which is incorporated into the roméite structure via the substitution Pb2+→A2+ where A2+ = Ca, Mn and Sr. Additionally, the cation occupancy at the six-fold coordinated B site, which is associated with the heterovalent substitution BFe3+ + Y☐→BSb5++YO2-, can strongly affect structural parameters.Chemical formulae of the roméite minerals group are discussed. According to crystal-chemical information, the species associated with the name ‘kenoplumboroméite’, hydroxycalcioroméite and fluorcalcioroméite most closely approximate end-member compositions Pb2(SbFe3+)O6☐, Ca2(Sb5+Ti) O6(OH) and (CaNa)Sb2O6F, respectively. However, in accord with pyrochlore nomenclature rules, their names correspond to multiple end-members and are best described by the general formulae: (Pb,#)2(Sb,#)2O6☐, (Ca,#)2(Sb,#)2O6(OH) and (Ca,#)Sb2(O,#)6F, where ‘#’ indicates an unspecified charge-balancing chemical substituent, including vacancies.

Characterization of the inclusion complex of the essential oil of Lantana camara L. and β-cyclodextrin by vibrational spectroscopy, GC–MS, and X-ray diffraction

2018 ◽  
Vol 91 (1-2) ◽  
pp. 95-104 ◽  
Author(s):  
Márcio dos S. Rocha ◽  
Sidney G. de Lima ◽  
Bartolomeu C. Viana ◽  
José Galberto Martins Costa ◽  
Francisco E. P. Santos
Keyword(s):  
Essential Oil ◽  
Inclusion Complex ◽  
Vibrational Spectroscopy ◽  
Lantana Camara ◽  
X Ray Diffraction ◽  
X Ray

Synthèse et caractérisation des oxypentafluorouranates(VI) NH4UOF5, KUOF5, RbUOF5 et CsUOF5

1978 ◽  
Vol 56 (14) ◽  
pp. 1874-1880 ◽  
Author(s):  
Philippe Joubert ◽  
Roland Bougon ◽  
Bernard Gaudreau
Keyword(s):  
Infrared Spectroscopy ◽  
Solid State ◽  
Alkali Metal ◽  
Vibrational Spectroscopy ◽  
Uranium Atom ◽  
The Other ◽  
Metal Fluoride ◽  
X Ray Diffraction ◽  
X Ray ◽  
Raman And Infrared Spectroscopy

The oxypentafluorouranates(VI) MUOF5, where M = NH4, K, Rb, Cs, have been synthetized from reaction of UOF4 with the ammonium or corresponding alkali metal fluoride in liquid SO2. According to X-ray diffraction, Raman and infrared spectroscopy, and from an isomorphism with the corresponding hexafluorouranates(V) MUF6, two different environments around the uranium atom are observed. In CsUOF5 the five fluorine atoms and the oxygen around the uranium result in a pseudo-octahedral surrounding whereas for the other complexes (M = NH4, K, Rb) each uranium is surrounded by eight light atoms forming a dodecahedron. In this structure the dodecahedra are linked together by fluorine atoms to form infinite chains. The UOF5− ion has been characterized by vibrational spectroscopy in the solid state. The proposed assignment, which was made with the assumption of a C4v symmetry of the UOF5− ion, was confirmed by a force constant calculation. From these data and contrary to the values reported for comparable oxypentafluoroanions, the axial fluorine is found to be less ionic than the equatorial ones.

Relationship Between Thermal Expansion and Crystal Chemical Parameters in Diborides

1986 ◽  
Vol 30 ◽  
pp. 503-510
Author(s):  
H.A. McKinstry ◽  
Lai Daik Chai ◽  
R.V. Sara ◽  
K.E. Spear
Keyword(s):  
Thermal Expansion ◽  
High Temperature ◽  
Zirconium Phosphate ◽  
Hexagonal Structure ◽  
Crystal Chemical ◽  
X Ray Diffraction ◽  
Chemical Parameters ◽  
X Ray ◽  
Sodium Zirconium ◽  
Sodium Zirconium Phosphate

Thermal expansion is an interesting, ubiquitous and neglected property of materials. Recently, Lenain et al. (1985) and Limaye (1986) have been investigating anisotropy in the low-expansion structures of the sodium zirconium phosphate family. In the hexagonal structure one axis expands while another contracts. In going from the calcium to the strontium analog the anisotropy actually changes sign. A change in anisotropy between CrB2 and TiB2 had been observed by R.V. Sara (1960). The results in Fig. 1 obtained by high temperature x-ray diffraction measurements indicate that for TiB2 the thermal expansion of the c-axis is greater than the expansion of the a-axis, whereas for CrB2 the reverse is true.

Al analogue of chayesite from a lamproite of Cancarix, SE Spain, and its crystal structure

2020 ◽  
Vol 196 (3) ◽  
pp. 193-198
Author(s):  
Natalia V. Zubkova ◽  
Nikita V. Chukanov ◽  
Christof Schäfer ◽  
Konstantin V. Van ◽  
Igor V. Pekov ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Diffraction Data ◽  
Empirical Formula ◽  
Structure Refinement ◽  
Crystal Chemical ◽  
Chemical Formula ◽  
Crystal Chemical Formula ◽  
X Ray Diffraction ◽  
Se Spain ◽  
X Ray

Al analogue of chayesite (with Al > Fe3+) was found in a lamproite from Cancarix, SE Spain. The mineral forms green thick-tabular crystals up to 0.4 mm across in cavities. The empirical formula derived from EMP measurements and calculated on the basis of 17 Mg + Fe + Al + Si apfu is (K0.75 Na0.20 Ca0.11)Mg3.04 Fe0.99 Al1.18 Si11.80 O30. The crystal structure was determined from single crystal X-ray diffraction data ( R = 2.38%). The mineral is hexagonal, space group P 6/ mcc, a = 10.09199(12), c = 14.35079(19) Å, V = 1265.78(3) Å3, Z = 2. Fe is predominantly divalent. Al is mainly distributed between the octahedral A site and the tetrahedral T 2 site. The crystal chemical formula derived from the structure refinement is C (K0.73 Na0.16 Ca0.11)B (Na0.02)4 A(Mg0.42 Al0.29 Fe0.29)2 T 2(Mg0.71 Fe0.16 Al0.13)3 T 1(Si0.985 Al0.015)12 O30.

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