scholarly journals Complex Disorder in Type-I Clathrates: Synthesis and Structural Characterization of A8GaxSn46−x (A = Rb, Cs; 6.9 < x < 7.5)

Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 298
Author(s):  
Sviatoslav A. Baranets ◽  
Amanda B. Childs ◽  
Hua He ◽  
Svilen Bobev
Keyword(s):  
Single Crystal ◽  
Exact Nature ◽  
Type I ◽  
X Ray Diffraction ◽  
Structural Variations ◽  
Zintl Phases ◽  
Experimental Conditions ◽  
Group 13 ◽  
X Ray ◽  
The Matrix

Exploratory studies in the systems Rb–Ga–Sn and Cs–Ga–Sn yielded the cubic type-I clathrates with refined compositions Rb8GaxSn46−x and Cs8GaxSn46−x (6.9 < x < 7.5). Nearly single-phase materials with good crystallinity were obtained from stoichiometric reactions of the elements. The structures were characterized by means of single-crystal X-ray diffraction methods. Both Rb8GaxSn46−x and Cs8GaxSn46−x represents cases, where a Group 13 element randomly substitutes a Group 14 element in the structure. The extent of Ga/Sn mixing is apparently governed by the drive of the system to achieve an optimal valence electron count, and hence, Rb8GaxSn46−x and Cs8GaxSn46−x (x ≈ 8) can be regarded as Zintl phases. This notion is supported by structure refinements on a multitude of single-crystal X-ray diffraction data, which also confirm that both types of cages in the cubic type-I structure are fully occupied by Rb and Cs atoms. The open-framework, comprised of 46 nodes per formula unit, adapts to the incorporation of nearly eight Ga atoms within the matrix of Sn, whereby small, short-range distortions result. The exact nature of these effects is still unclear, as so far, the structural variations could only be modeled as both positional and occupational disorder at one of three framework sites. Since vacancies in the structures of the binary type-I clathrates A8Sn46−x☐x (A = Rb, Cs; ☐ = missing Sn atom) are also known to cause local distortions, the latter were also synthesized with the same protocols used for the synthesis of A8GaxSn46−x and structurally re-analyzed. The results from the latter studies confirm that homogeneity issues abound, and that the final structures/compositions are an intricate function of the experimental conditions.

Structural variations in the brownmillerite series Ca2(Fe2−xAlx)O5: Single-crystal X-ray diffraction at 25 °C and high-temperature X-ray powder diffraction (25 °C ≤T≤ 1000 °C)

2004 ◽  
Vol 89 (2-3) ◽  
pp. 405-420 ◽  
Author(s):  
Günther J. Redhammer ◽  
Gerold Tippelt ◽  
Georg Roth ◽  
Georg Amthauer
Keyword(s):  
High Temperature ◽  
Single Crystal ◽  
Powder Diffraction ◽  
X Ray Diffraction ◽  
Structural Variations ◽  
X Ray

Preparation and Characterisation of Iodo-functionalised Azobenzene Derivatives of the Type I–p-C6H4–N=N–p-C6H4–X

2008 ◽  
Vol 63 (12) ◽  
pp. 1395-1401 ◽  
Author(s):  
Ulrich Siemeling ◽  
Clemens Bruhn ◽  
Mario Meier ◽  
Christian Schirrmacher
Keyword(s):  
Single Crystal ◽  
Structure Analysis ◽  
General Type ◽  
Starting Material ◽  
Type I ◽  
X Ray Diffraction ◽  
Ferrocene Derivative ◽  
X Ray ◽  
Derivatives Of ◽  
Azobenzene Derivatives

A broad range of azobenzene derivates of the general type I-p-C6H4-N=N-p-C6H4-X (1) have been prepared. In the case of X = Ph (b), C≡C-Fc (e, Fc = ferrocenyl), OMe (g), Oi-Pr (i), and NMe2 (m), these compounds have been characterised by single-crystal X-ray structure analysis. In addition, the closely related 4-dimethylamino-1-(4-iodophenylazo)naphthalene 2 and 8-(4-iodophenylazo) quinoline 3 have also been prepared. Furthermore, the ferrocene derivative Fc-C≡C-p-C6H4- NH2 (4), which served as a starting material for the synthesis of I-p-C6H4-N=N-p-C6H4-p-C6H4- C≡C-Fc (1e), was prepared and structurally characterised by X-ray diffraction.

Eine Zintl-Phase mit isolierten SnSb48-Anionen: Na8SnSb4 / A Zintl Phase with Isolated SnSb48- -Anions, Na8SnSb4

1988 ◽  
Vol 43 (1) ◽  
pp. 69-71 ◽  
Author(s):  
Brigitte Eisenmann ◽  
Jürgen Klein
Keyword(s):  
Single Crystal ◽  
Bond Length ◽  
Glassy Carbon ◽  
Diffraction Data ◽  
X Ray Diffraction ◽  
Zintl Phases ◽  
Zintl Phase ◽  
Space Group ◽  
X Ray

Abstract The new compound Na8SnSb4 has been prepared from appropriate mixtures of the elements at 700 °C in evacuated silica ampoules coated with glassy carbon. The structure has been determined by single crystal X-ray diffraction data (cubic, space group Fd3m, a - 1481.6(3) pm, Z = 8, R = 0.044 for 263 reflections). There are isolated tetrahedral SnSb48- units (bond length Sn -Sb = 284.3 pm), proving the compound to belong to the Zintl phases.

Structural variations accompanied by thermal expansion of diaspore: in-situ single-crystal and powder X-ray diffraction study

2018 ◽  
Vol 45 (10) ◽  
pp. 1003-1010
Author(s):  
Teruki Sugiura ◽  
Hiroshi Arima ◽  
Takaya Nagai ◽  
Kazumasa Sugiyama
Keyword(s):  
Thermal Expansion ◽  
Single Crystal ◽  
Diffraction Study ◽  
X Ray Diffraction ◽  
Structural Variations ◽  
X Ray

scholarly journals Effect of the Basicity on Mineralogical Phases and Micro-Structure of Dephosphorization Slag in the New Double Slag Converter Steelmaking Process

Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1480
Author(s):  
Wenkui Yang ◽  
Jian Yang ◽  
Runhao Zhang ◽  
Han Sun ◽  
Yunlong Qiu
Keyword(s):  
Liquid Phase ◽  
X Ray Diffraction ◽  
Hot Metal ◽  
Experimental Conditions ◽  
Rich Phase ◽  
X Ray ◽  
Structure Unit ◽  
P Content ◽  
The Matrix ◽  
Dephosphorization Slag

In the present work, the effect of the basicity at the lower range from 0.98 to 2.13 on dephosphorization of hot metal at 1623 K was studied through high-temperature laboratorial experiments. With the increase of the basicity from 0.98 to 2.13, the P and C contents in hot metal rapidly decrease and increase at first, and then gradually decrease and increase, respectively. From the scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS) and X-ray diffraction (XRD) results, with the increase of the basicity, the phase containing the high P content changes from the matrix phase into the phosphorus (P)-rich phase. Under the present experimental conditions, the P-rich phase can only be precipitated from the liquid slag when the basicity is higher than 1.55, which is a benefit to the dephosphorization. As the Raman intensity of the P-O-Ca structure unit in the P-rich phase is significantly higher than that of the P-O-Si structure unit, most of the phosphorus in the P-rich phase exists in the P-O-Ca structure unit and a small amount of phosphorus exists in the P-O-Si structure unit. With the increase of the basicity of the dephosphorization slag, the activity coefficient of P2O5, γ(P2O5) , in the liquid phase decreases, while the basicity in the liquid phase increases.

Compositional and structural variations in the ternary system Li – Al – Si

2003 ◽  
Vol 218 (11) ◽  
Author(s):  
Laurent Spina ◽  
Yong Zhong Jia ◽  
Bernard Ducourant ◽  
Monique Tillard ◽  
Claude Belin
Keyword(s):  
Ternary System ◽  
Single Crystal ◽  
Diffraction Data ◽  
X Ray Diffraction ◽  
Structural Variations ◽  
X Ray

AbstractThe Li–Al–Si ternary system has been investigated and four ternary phases characterized using both powder and single crystal X-ray diffraction data. LiAlSi and Li

Electron Microscopy of Shock Loaded Polycrystalline Beryllium

1974 ◽  
Vol 32 ◽  
pp. 506-507 ◽  
Author(s):  
J. M. Galbraith ◽  
L. E. Murr ◽  
A. L. Stevens
Keyword(s):  
Electron Microscopy ◽  
Wave Propagation ◽  
Structural Change ◽  
Single Crystal ◽  
Diffraction Pattern ◽  
Shock Loading ◽  
Slip Systems ◽  
Compression Tests ◽  
X Ray Diffraction ◽  
X Ray

Uniaxial compression tests and hydrostatic tests at pressures up to 27 kbars have been performed to determine operating slip systems in single crystal and polycrystal1ine beryllium. A recent study has been made of wave propagation in single crystal beryllium by shock loading to selectively activate various slip systems, and this has been followed by a study of wave propagation and spallation in textured, polycrystal1ine beryllium. An alteration in the X-ray diffraction pattern has been noted after shock loading, but this alteration has not yet been correlated with any structural change occurring during shock loading of polycrystal1ine beryllium.This study is being conducted in an effort to characterize the effects of shock loading on textured, polycrystal1ine beryllium. Samples were fabricated from a billet of Kawecki-Berylco hot pressed HP-10 beryllium.

Crystal structure of an inclusion complex between chiral monoaza-15-crown-5 and S(–)-1-phenyl-ethyl ammonium percholorate

2003 ◽  
Vol 218 (5) ◽  
Author(s):  
Süheyla Özbey ◽  
F. B. Kaynak ◽  
M. Toğrul ◽  
N. Demirel ◽  
H. Hoşgören
Keyword(s):  
Crystal Structure ◽  
Inclusion Complex ◽  
Single Crystal ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
New Type

AbstractA new type of inclusion complex, S(–)-1 phenyl ethyl ammonium percholorate complex of R-(–)-2-ethyl - N - benzyl - 4, 7, 10, 13 - tetraoxa -1- azacyclopentadecane, has been prepared and studied by NMR, IR and single crystal X-ray diffraction techniques. The compound crystallizes in space group

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