Notizen: Ga0,5V2Se4, eine neue gemischtvalente Verbindung mit Spinellstruktur / Ga0,5V2Se4, a New Mixed Valence Compound with Spinel Structure

1992 ◽  
Vol 47 (6) ◽  
pp. 901-902 ◽  
Author(s):  
H. Haeuseler ◽  
W. Cordes
Keyword(s):  
Infrared Spectroscopy ◽  
Spinel Structure ◽  
Mixed Valence ◽  
Lattice Parameter ◽  
X Ray ◽  
Tetrahedral Sites ◽  
Mixed Valence Compound

The mixed valence compound Ga0,5V2Se4 has been prepared and characterized by X-ray powder methods and infrared spectroscopy. The compound crystallizes in a spinel structure with 1:1 ordering on the tetrahedral sites. The lattice parameter of the cubic cell is a = 1013.8 pm.

Die neuen Oxobismutate(III) Cs6Bi4O9, K9Bi5O13 und A2Bi4O7 (A = Rb, Cs) / The New Oxobismutates(III) Cs6Bi4O9, K9Bi5O13 and A2Bi4O7 (A = Rb, Cs)

2002 ◽  
Vol 57 (10) ◽  
pp. 1090-1100
Author(s):  
Franziska Emmerling ◽  
Caroline Röhr
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Alkali Metals ◽  
Mixed Valence ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Trigonal Bipyramidal ◽  
Mixed Valence Compound

AbstractThe title compounds were synthesized at a temperature of 700 °C via oxidation of elemental Bi with the hyperoxides AO2 or via reaction of the elemental alkali metals A with Bi2O3. Their crystal structures have been determined by single crystal x-ray diffraction. They are dominated by two possible surroundings of Bi by O, the ψ-trigonal-bipyramidal three (B) and the ψ-tetrahedral four (T) coordination. Cs6Bi4O9 (triclinic, spacegroup P1̄, a = 813.82(12), b = 991.60(14), c = 1213.83(18) pm, α = 103.658(2), β = 93.694(3), γ = 91.662(3)°, Z = 2) contains centrosymmetric chain segmentes [Bi8O18]12- with six three- (T) and two four-coordinated (B) Bi(III) centers. K9Bi5O13 (monoclinic, spacegroup P21/c, a = 1510.98(14), b = 567.59(5), c = 2685.6(2) pm, β = 111.190(2)°, Z = 4) is a mixed valence compound with isolated [BivO4]3- tetrahedra and chains [BiIII4O9]6- of two T and two B coordinated Bi. In the compounds A2Bi4O7 (A = Rb/Cs: monoclinic, C2/c, a = 2037.0(3) / 2130.6(12), b = 1285.5(2) / 1301.9(7), c = 1566.6(2) / 1605.6(9) pm, β = 94.783(3) / 95.725(9)°, Z = 8) ribbons [Bi4O6O2/2]2- are formed, which are condensed to form a three-dimensional framework.

Ga1.93V0.97S4, eine neue gemischtvalente Verbindung mit α-FeGa2S4-Struktur / Ga1.93V0.97S4, a New Mixed Valent Compound with α-FeGa2S4 Structure

1995 ◽  
Vol 50 (5) ◽  
pp. 725-728 ◽  
Author(s):  
W. Cordes ◽  
S. Reil ◽  
H. Haeuseler
Keyword(s):  
Mixed Valence ◽  
Lattice Parameters ◽  
Hexagonal Cell ◽  
X Ray ◽  
Mixed Valence Compound

Abstract The mixed valence compound Ga1.93V0.97S4 has been prepared and characterized by X-ray powder methods. The compound crystallizes in an α-FeGa2S4 structure. The lattice parameters of the hexagonal cell are a = 363.6 and c = 1207.1 pm. The structure has been refined by Rietveld methods.

scholarly journals Compositional and structural variabilities of Mg-rich iron oxide spinels from tuffite

1999 ◽  
Vol 23 (4) ◽  
pp. 791-798 ◽  
Author(s):  
W. N. Mussel ◽  
J. D. Fabris ◽  
J. M. D. Coey ◽  
L. M. A. Sans ◽  
M. F. F. Lelis
Keyword(s):  
Iron Oxide ◽  
Room Temperature ◽  
Spontaneous Magnetization ◽  
Mixed Valence ◽  
Lattice Parameter ◽  
Zero Field ◽  
X Ray ◽  
Field Distributions ◽  
Hyperfine Field Distributions ◽  
Oxide Spinels

Maghemite (γFe2O3) from tuffite is exceptionally rich in Mg, relatively to most of those reportedly found in other mafic lithosystems. To investigate in detail the compositional and structural variabilities of this natural magnetic iron oxide, sets of crystals were isolated from samples collected at different positions in a tuffite weathering mantle. These sets of crystal were individually powdered and studied by X-ray diffractometry, Mössbauer spectroscopy, magnetization measurements and chemical analysis. Lattice parameter of the cubic cell (a0) was found to vary from 0.834(1) to 0.8412(1) nm. Lower a0-values are characteristic of maghemite whereas higher ones are related to a magnetite precursor. FeO content ranges up to 17 mass % and spontaneous magnetization ranges from 8 to 32 J T-1 kg-1. Zero-field room temperature Mössbauer spectra are rather complex, indicating that the hyperfine field distributions due to Fe3+ and mixed valence Fe3+/2+ overlap. The structural variabilities of the (Mg, Ti)-rich iron oxide spinels is essentially related to the range of chemical composition of its precursor (Mg, Ti)-rich magnetite, and probably to the extent to which it has been oxidized during transformation in soil.

Investigation of Copper Ferrite, Cu0.5Fe2.5O4, as a High Saturation Magnetization Material

1995 ◽  
Vol 401 ◽  
Author(s):  
D. Sriram ◽  
R. L. Snyder
Keyword(s):  
Saturation Magnetization ◽  
Spinel Structure ◽  
Lattice Parameter ◽  
Processing Route ◽  
Copper Ferrite ◽  
X Ray ◽  
Different Temperatures ◽  
A Site ◽  
State Processing

AbstractThe ferrite of composition Cu0.5Fe2.5O4, prepared using a conventional solid-state processing route, was soaked at different temperatures between 1200°C and 1350°C, for an hour, in air. The samples were rapidly quenched into oil. Mössbauer, resistivity and x-ray lattice parameter data were obtained for the quenched phase. The maximum saturation magnetization value, obtained at 10K, was close to 5.0μB. The characterization of the sample showed Cu+1 to be partially disordered across both A and B sites of the spinel structure, with an excess occupancy of the A-site showing that under the proper conditions the ordered high 4πMs Cu+1 phase will be stable.

Ruthenium-mediated dehydration of benzaldehyde oxime. X-ray crystal structure of the mixed-valence compound [RuBr(NCPh)5][RuBr4(NCPh)2]·PhCH2OH

Polyhedron ◽  
1997 ◽  
Vol 16 (14) ◽  
pp. 2429-2433 ◽  
Author(s):  
Yuri N. Kukushkin ◽  
Marina V. Bavina ◽  
Andrey V. Zinchenko ◽  
Vitaly K. Belsky ◽  
Vadim Yu. Kukushkin
Keyword(s):  
Crystal Structure ◽  
Mixed Valence ◽  
X Ray ◽  
Mixed Valence Compound

Notizen: (i-C37HNH3+)8(Cl-)4[SbCl6]3-[SbCl6]- eine neue mixed valence-Verbindung.

1976 ◽  
Vol 31 (9) ◽  
pp. 1285-1286 ◽  
Author(s):  
G. Birke ◽  
H. P. Latscha ◽  
H. Pritzkow
Keyword(s):  
Structure Analysis ◽  
Mixed Valence ◽  
X Ray ◽  
Mixed Valence Compound

The reaction between isopropylamine and isopropylammonium hexachloroantimonate(V) yields a red product of the composition C12H40Cl8N4Sb. The X-ray structure analysis showed that this is a mixed valence compound of SbCl63- and SbCl6- octahedra.

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