Sr7N2Sn3: a layered antiperovskite-type nitride stannide containing zigzag chains of Sn4 polyanions

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Hisanori Yamane ◽  
Simon Steinberg
Keyword(s):  
Ternary Compound ◽  
First Principles ◽  
Structural Features ◽  
Slow Cooling ◽  
X Ray ◽  
Cell Parameters ◽  
Structural Peculiarities ◽  
Orthorhombic Cell ◽  
Inverse Structure ◽  
The Ideal

Abstract Metallic black platelet single crystals of a new ternary compound, Sr7N2Sn3, were obtained by heating Sr and Sn in a Na flux together with NaN3 as a nitrogen source at 1073 K, followed by slow cooling. Single-crystal X-ray analysis revealed that this compound crystallizes in an orthorhombic cell with the cell parameters a = 10.4082(2), b = 18.0737(4), and c = 7.43390(10) Å (space group Pmna, Z = 2), and has a layered (modular) antiperovskite-type structure which could be related to the inverse structure of Ca2Nb2O7 ((Ca2)[Ca2Nb4O14]). Four-membered zigzag [Sn4] chains are situated between slabs comprising four antiperovskite layers cut by the (110) plane of the ideal anitiperovskite structure, and Sr7N2Sn3 can be expressed as [Sn4][Sn2N4Sr14]. Although an electron-precise valence electron distribution according to the formula (Sr2+)14(N3−)4(Sn4−)2([Sn4]8−) is proposed for this ternary compound, yet, there are certain structural peculiarities which cannot be explained by this idealized picture. Therefore, first principles-based means were employed to account for the aforementioned structural features.

Heklaite, KNaSiF6, a new fumarolic mineral from Hekla volcano, Iceland

2010 ◽  
Vol 74 (1) ◽  
pp. 147-157 ◽  
Author(s):  
A. Garavelli ◽  
T. Balić-Žunić ◽  
D. Mitolo ◽  
P. Acquafredda ◽  
E. Leonardsen ◽  
...  
Keyword(s):  
Powder Diffraction ◽  
Quantitative Chemical Analysis ◽  
Unit Cell Parameters ◽  
Orthorhombic Space Group ◽  
Synthetic Compound ◽  
Calculated Density ◽  
X Ray ◽  
Cell Parameters ◽  
Fine Grained ◽  
The Ideal

AbstractHeklaite, with the ideal formula KNaSiF6, was found among fumarolic encrustations collected in 1992 on the Hekla volcano, Iceland. Heklaite forms a fine-grained mass of micron- to sub-micron-sized crystals intimately associated with malladrite, hieratite and ralstonite. The mineral is colourless, transparent, non-fluorescent, has a vitreous lustre and a white streak. The calculated density is 2.69 g cm–3. An SEM-EDS quantitative chemical analysis shows the following range of concentrations (wt.%): Na 11.61–12.74 (average 11.98), K 17.02–18.97 (average 18.29), Si 13.48 –14.17 (average 13.91), F 54.88–56.19 (average 55.66). The empirical chemical formula, calculated on the basis of 9 a.p.f.u., is Na1.07K0.96Si1.01F5.97. X-ray powder diffraction indicates that heklaite is orthorhombic, space group Pnma, with the following unit-cell parameters: a = 9.3387(7) Å, b = 5.5032(4) Å, c = 9.7957(8) Å , V = 503.43(7) Å3, Z = 4. The eight strongest reflections in the powder diffraction pattern [d in Å (I/I0) (hkl)] are: 4.33 (53) (102); 4.26 (56) (111); 3.40 (49) (112); 3.37 (47) (202); 3.34 (100) (211); 2.251 (27) (303); 2.050 (52) (123); 2.016 (29) (321). On the basis of chemical analyses and X-ray data, heklaite corresponds to the synthetic compound KNaSiF6. The name is for the type locality, the Hekla volcano, Iceland.

Arrheniusite-(Ce), CaMg[(Ce7Y3)Ca5](SiO4)3(Si3B3O18)(AsO4)(BO3)F11, a New Member of the Vicanite Group, from the Östanmossa Mine, Norberg, Sweden

2021 ◽  
Author(s):  
Dan Holtstam ◽  
Luca Bindi ◽  
Paola Bonazzi ◽  
Hans-Jürgen Förster ◽  
Ulf B. Andersson
Keyword(s):  
Structure Refinement ◽  
New Mineral ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Calculated Density ◽  
Epma Data ◽  
X Ray ◽  
Cell Parameters ◽  
Greenish Yellow ◽  
The Ideal

ABSTRACT Arrheniusite-(Ce) is a new mineral (IMA 2019-086) from the Östanmossa mine, one of the Bastnäs-type deposits in the Bergslagen ore region, Sweden. It occurs in a metasomatic F-rich skarn, associated with dolomite, tremolite, talc, magnetite, calcite, pyrite, dollaseite-(Ce), parisite-(Ce), bastnäsite-(Ce), fluorbritholite-(Ce), and gadolinite-(Nd). Arrheniusite-(Ce) forms anhedral, greenish-yellow translucent grains, exceptionally up to 0.8 mm in diameter. It is optically uniaxial (–), with ω = 1.750(5), ε = 1.725(5), and non-pleochroic in thin section. The calculated density is 4.78(1) g/cm3. Arrheniusite-(Ce) is trigonal, space group R3m, with unit-cell parameters a = 10.8082(3) Å, c = 27.5196(9) Å, and V = 2784.07(14) Å3 for Z = 3. The crystal structure was refined from X-ray diffraction data to R1 = 3.85% for 2286 observed reflections [Fo > 4σ(Fo)]. The empirical formula for the fragment used for the structural study, based on EPMA data and results from the structure refinement, is: (Ca0.65As3+0.35)Σ1(Mg0.57Fe2+0.30As5+0.10Al0.03)Σ1[(Ce2.24Nd2.13La0.86Gd0.74Sm0.71Pr0.37)Σ7.05(Y2.76Dy0.26Er0.11Tb0.08Tm0.01Ho0.04Yb0.01)Σ3.27Ca4.14]Σ14.46(SiO4)3[(Si3.26B2.74)Σ6O17.31F0.69][(As5+0.65Si0.22P0.13)Σ1O4](B0.77O3)F11; the ideal formula obtained is CaMg[(Ce7Y3)Ca5](SiO4)3(Si3B3O18)(AsO4)(BO3)F11. Arrheniusite-(Ce) belongs to the vicanite group of minerals and is distinct from other isostructural members mainly by having a Mg-dominant, octahedrally coordinated site (M6); it can be considered a Mg-As analog to hundholmenite-(Y). The threefold coordinated T5 site is partly occupied by B, like in laptevite-(Ce) and vicanite-(Ce). The mineral name honors C.A. Arrhenius (1757–1824), a Swedish officer and chemist, who first discovered gadolinite-(Y) from the famous Ytterby pegmatite quarry.

Growth defects and infrared spectra analysis of CePO4single crystals

2005 ◽  
Vol 38 (4) ◽  
pp. 675-677 ◽  
Author(s):  
Kunpeng Wang ◽  
Jianxiu Zhang ◽  
Jiyang Wang ◽  
Changshui Fang ◽  
Wentao Yu ◽  
...  
Keyword(s):  
Slow Cooling ◽  
Spectra Analysis ◽  
X Ray ◽  
Cell Parameters ◽  
Growth Defects ◽  
Cooling Method ◽  
Good Crystalline Quality ◽  
Growth Habits ◽  
Top Seeded Solution Growth

High-quality CePO4single crystals (monazite) were grown by the flux TSSG (top-seeded-solution growth) slow-cooling method. The X-ray powder diffraction pattern shows good crystalline quality of the crystals and the various peaks were assigned. The unit-cell parameters were calculated using theDICVOL90andTERORcomputer programs. The concentrations of all elements in the crystals were measured by electron probe microanalysis. Growth habits were deduced by the Bravais–Friedel Donnay–Harker (BFDH) method and macro-defects in the crystals are discussed. An infrared spectrum of the crystal was recorded in the frequency range of 300 to 1600 cm−1and all vibration frequency peaks were assigned.

scholarly journals Lead-antimony sulfosalts from Tuscany (Italy). XVIII. New data on the crystal-chemistry of boscardinite

2017 ◽  
Vol 81 (1) ◽  
pp. 47-60 ◽  
Author(s):  
Cristian Biagioni ◽  
Yves Moëlo
Keyword(s):  
Single Crystal ◽  
Diffraction Study ◽  
Type Specimen ◽  
Structural Features ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Mineral Associations ◽  
Crystal Chemical Data ◽  
New Findings

AbstractBoscardinite, ideally TlPb4(Sb7As2)∑9S18, has been described recently as a new homeotypic derivative of baumhauerite, found at Monte Arsiccio mine, Apuan Alps, Tuscany, Italy. New findings of boscardinite in different mineral associations of this deposit have allowed the collection of new crystal-chemical data. Electron-microprobe analysis of the crystal used for the single-crystal X-ray diffraction study gave (in wt.%): Ag 1.81(5), Tl 12.60(21), Pb 17.99(12), Hg 0.14(5), As 9.36(12), Sb 33.60(27), S 23.41(30),Cl 0.06(1), total 98.97(100). On the basis of ∑Me= 14 apfu, it corresponds to Ag0.42Tl1.52Pb2.14Hg0.02(Sb6.82As3.08)∑9.90S18.04Cl0.04. With respect to the type specimen, these new findings are characterized by a strong Pb depletion, coupled with higher Tl contents, and a significant As enrichment. The single-crystal X-ray diffraction study of this (Tl,As)-enriched boscardinite confirms the structural features described for the type sample. The unit-cell parameters area= 8.1017(4),b= 8.6597(4),c= 22.5574(10) Å, α = 90.666(2), β = 97.242(2), γ = 90.850(2)°,V= 1569.63(12) Å3, space groupP̄1. The crystal structure was refined down toR1= 0.0285 on the basis of 6582 reflections withFo> 4σ(Fo). Arsenic is dominant in threeMeS3sites, compared to one in type boscardinite. The main As-enrichment is observed in the sartorite-type sub-layer. Owing to this chemical peculiarity, (Tl, As)-rich boscardinite shows alternation, alongb, of Sb-rich sites and As-rich sites; this feature represents the main factor controlling the 8 Å superstructure. The chemical variability of boscardinite is discussed; the Ag increase observed here gets closer to stoichiometric AgTl3Pb4(Sb14As6)∑20S36(Z= 1), against possible extension up to AgTl2Pb6(Sb15As4)∑19S36for type boscardinite.

A barian bannisterite from Japan

1989 ◽  
Vol 53 (369) ◽  
pp. 85-87 ◽  
Author(s):  
S. Matsubara ◽  
A. Kato
Keyword(s):  
Unit Cell ◽  
Powder Pattern ◽  
Chemical Analyses ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Ideal Formula ◽  
The Ideal

AbstractChemical analyses of bannisterite from the Kamo mine, Toba City, Mie Prefecture, Japan, give Ba : Ca = 69:31–55:45, yielding the ideal formula with Ba > Ca, i.e. (Ba,Ca)(K,H3O)(Mn2+ · Mg,Fe2+)21 (Si,Al)32(O,OH)92 · nH2O, where Ba > Ca, Mn2+ > Mg, Fe2+,Si ≫ Al, and O > OH. The unit cell parameters calculated after the indexing of the X-ray powder pattern are: a = 22.95, b = 16.52, c = 25.66 Å, β = 94.2°. It occurs as dark brown veinlets cutting massive caryopilite-rhodochrosite ore, which is also cut by veinlets of manganoan chlorite (Mn/(Mg + Mn + Fe) = c. 0.30–0.39) with minor barian orthoclase (Ba/(K+ Ba) = 0.05 ∼ 0.06).

Oxygen content, microstructure, and superconductivity of YBa2Cu3O7−x

1987 ◽  
Vol 2 (6) ◽  
pp. 743-749 ◽  
Author(s):  
M. P. A. Viegers ◽  
D. M. de Leeuw ◽  
C. A. H. A. Mutsaers ◽  
H. A. M. van Hal ◽  
H. C. A. Smoorenburg ◽  
...  
Keyword(s):  
Single Phase ◽  
Inner Core ◽  
X Ray ◽  
Cell Parameters ◽  
Preparation Conditions ◽  
Transmission Electron ◽  
Quench Temperature ◽  
Orthorhombic Cell ◽  
The Difference ◽  
Individual Grains

The influence of preparation conditions and microstructure on the superconductive properties of single-phase poly-crystalline YBa2Cu3O7−x was investigated by electron probe microanalysis, transmission electron microscopy (TEM), and x-ray powder diffraction as a function of temperature in various ambients supplemented by resistivity and susceptibility measurements. Leaching of Ba was observed when samples were brought in contact with water. The TEM imaging revealed that individual grains have an extremely defect-rich outer shell and an inner core with a domain structure with a and b axes interchanged. The transition temperature Tc was found to decrease with increasing quench temperature in the range 400–900°C. The Tc was observed to be linearly proportional to the difference in the orthorhombic cell parameters (b-a). Further implications are discussed.

New X-ray powder diffraction data for heterometallic complexes with unsaturated organic ligands Cp(CO)2MnPt(μ-C=CHPh)(η2-dppm), [Cp(CO)2MnCu(μ-C=CHPh)]2(μ-Cl)2, CpMnFe2(μ3-C=CHPh)(CO)8 and η4-[Cp(CO)2MnC(CO)CHPh]Fe(CO)3(Cp=η5-C5H5;dppm=Ph2PCH2PPh2)

2005 ◽  
Vol 20 (3) ◽  
pp. 246-253
Author(s):  
Alla B. Antonova ◽  
Oleg S. Chudin ◽  
Sergei D. Kirik
Keyword(s):  
Powder Diffraction ◽  
Heterometallic Complexes ◽  
Carbonyl Complexes ◽  
Unit Cell Parameters ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
Orthorhombic Cell ◽  
Monoclinic Cell ◽  
Good Agreement

Four heterometallic carbonyl complexes: (1) Cp(CO)2MnPt(μ-C=CHPh)dppm) (2) [Cp(CO)2MnCu(μ-C=CHPh)(μ-Cl)]2, (3) CpMnFe2(μ3-C=CHPh)(CO)8, and (4) η4-[Cp(CO)2MnC(CO)CHPh]Fe(CO)3 have been studied by X-ray powder diffraction and their unit cell parameters are reported. Orthorhombic cell parameters for complex (1) are a=18.5719(14) Å, b=18.6092(14) Å, c=23.8117(18) Å, Z=8, space group Pbca. Monoclinic cell parameters found for complex (2) are a=11.5816(5) Å, b=7.9784(5) Å, c=16.7819(7) Å, β=105.460(2)°, Z=2, space group P21∕n. Orthorhombic cell parameters for complex (3) are a=13.5260(9) Å, b=15.1487(10) Å, c=10.3330(6) Å, Z=4, space group Pna21. Monoclinic cell parameters for complex (4) are a=10.3545(45) Å, b=8.0002(43) Å, c=21.8355(95) Å, β=102.89(2), Z=4, space group P21∕c. Parameters found for complexes (1–4) are in good agreement with those obtained from single crystal X-ray diffractometry.

CeLi2As2, eine ternäre Verbindung im CaAl2Si2-Typ / CeLi2As2, a Ternary Compound in the CaAl2Si2-Type

1979 ◽  
Vol 34 (8) ◽  
pp. 1169-1170 ◽  
Author(s):  
Hans-Uwe Schuster ◽  
Herrad-Odilia Fischer
Keyword(s):  
Ternary Compound ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
Structure Space

X-ray investigations on the ternary compound CeLi2As2 showed it to crystallize in the trigonal CaAl2Si-2-structure, space group P3̄m1-D33d- The cell parameters are: a = 431,1 pm, c = 698,4 pm, c/a = 1,62

Crystal chemistry and binding of NO2, SCN and SeCN to Co in cobalamins

2003 ◽  
Vol 59 (1) ◽  
pp. 51-59 ◽  
Author(s):  
Gianpiero Garau ◽  
Silvano Geremia ◽  
Luigi G. Marzilli ◽  
Giorgio Nardin ◽  
Lucio Randaccio ◽  
...  
Keyword(s):  
Nitro Group ◽  
Crystal Chemistry ◽  
Structural Features ◽  
Close Packing ◽  
Synchrotron Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Coordination Isomers ◽  
Equatorial Ligand

Results of the accurate crystal structure determination of NO2Cbl·2LiCl (1), NO2Cbl·NaCl (2), NCSCbl (3) and NCSeCbl (4), based on synchrotron diffraction data collected at 100 K, are described. The nitro group in (1) was found to be disordered with two orientations that differ by a rotation of ∼60° about the Co—NO2 bond, whereas in (2) the nitro group has only one orientation. The first X-ray structural determination of a cobalamin with a Co—Se bond is reported. Comparison of the axial distances indicates that SeCN has a bond length of 2.384 (3) Å and that the trans influence on the Co—N bond is only slightly greater than that of SCN. The crystals of the thiocyanate cobalamin contain both the S- and N-bonded coordination isomers in a 3:2 ratio. The structural features of the Co—S bond in cobalamins are discussed. The crystal chemistry of cobalamins is discussed in terms of packing of roughly spherical molecules. The unit-cell parameters can be used to group the cobalamins' crystal structures in different arrays intermediate between distorted hexagonal close packing and primitive hexagonal arrangements. The structural features of cobalamins, and of cobaloximes that have the same axial fragment as the cobalamins, are reviewed and discussed in terms of the cis influence of the equatorial ligand.

The crystal structure of camerolaite and structural variation in the cyanotrichite family of merotypes

2014 ◽  
Vol 78 (7) ◽  
pp. 1527-1552 ◽  
Author(s):  
S. J. Mills ◽  
A. G. Christy ◽  
C. Schnyder ◽  
G. Favreau ◽  
J. R. Price
Keyword(s):  
Crystal Structure ◽  
X Ray Diffraction ◽  
Structure Variation ◽  
X Ray ◽  
Cell Parameters ◽  
Average Structure ◽  
X Ray Scattering ◽  
Group Members ◽  
Low Symmetry ◽  
The Ideal

AbstractWe present Raman data for camerolaite, cyanotrichite and carbonatecyanotrichite, and using synchrotron single-crystal X-ray diffraction have solved the structure of camerolaite from the Tistoulet Mine, Padern, Aude Department, France. Camerolaite crystallizes in space group P1 with the unit-cell parameters: a = 6.3310(13) Å, b = 2.9130(6) Å, c = 10.727(2) Å, α = 93.77(3)°, β = 96.34(3)°, γ =79.03(3)º, V = 192.82(7) Å3 and Z = ⅓, with respect to the ideal formula from the refinement, Cu6Al3(OH)18(H2O)2[Sb(OH)6](SO4). The crystal structure was solved to R1 = 0.0890 for all 1875 observed reflections [Fo > 4σFo] and 0.0946 for all 2019 unique reflections. The P cell has been transformed into a C-centred cell that aids comparison with that of the structurally related khaidarkanite by aC = 2aP – bP, giving parameters a = 12.441(3), b = 2.9130(6), c = 10.727(2) Å, α = 93.77(3), β = 95.57(3), γ = 92.32(3)º and Z = ⅔ in C1. Edge-sharing octahedral ribbons Cu2Al(O,OH,H2O)8 form hydrogen-bonded layers || (001), as in khaidarkanite. The partially occupied interlayer Sb and S sites of the average structure are in octahedral and tetrahedral coordination by oxygen, respectively. They cannot be occupied simultaneously, which leads to regular alternation of [Sb(OH)6]– and SO42– groups in rods || y, resulting in local tripling of the periodicity along y for the Sb(OH)6–SO4 rods. Thus, camerolaite has a ‘host–guest’ structure in which an invariant host module (layers of Cu–Al ribbons) has embedded rod-like guest modules with a longer periodicity. Coupling between the phases of these rods is only short-range, resulting in diffuse X-ray scattering rather than sharp superstructure reflections. Similar disorder is known for parnauite, and is deduced for other members of the cyanotrichite group (cyanotrichite, carbonatecyanotrichite and khaidarkanite). Group members all share the Cu–Al ribbon module but have interlayer rods of different compositions and topologies; thus, they form a merotypic family. The low symmetry of the camerolaite average structure suggests other possibilities for structure variation in the group, which are discussed.

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