Crystal Structure, Mössbauer Spectra, Thermal Expansion, and Phase Transition of Berthierite FeSb2S4

2001 ◽  
Vol 162 (1) ◽  
pp. 79-83 ◽  
Author(s):  
K. Łukaszewicz ◽  
A. Pietraszko ◽  
J. Stępień-Damm ◽  
A. Kajokas ◽  
J. Grigas ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Thermal Expansion ◽  
Mössbauer Spectra ◽  
Mossbauer Spectra

A high temperature structural phase transition in crocoite (PbCrO4) at 1068 K: crystal structure refinement at 1073 K and thermal expansion tensor determination at 1000 K

2000 ◽  
Vol 64 (2) ◽  
pp. 291-300 ◽  
Author(s):  
K. S. Knight
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Thermal Expansion ◽  
High Temperature ◽  
Structural Phase Transition ◽  
Structural Phase ◽  
Structure Type ◽  
Temperature Phase ◽  
Thermal Expansion Tensor ◽  
Principal Axes

AbstractHigh-resolution, neutron time-of-flight, powder diffraction data have been collected on natural crocoite between 873 and 1073 K. Thermal analysis carried out in the 1920s had suggested that chemically pure PbCrO4 exhibited two structural phase transitions, at 964 K, to the β phase, and at 1056 K, to the γ phase. In this study, no evidence was found for the α-β structural phase transition, however a high-temperature phase transition was found at ∼1068 K from the ambient-temperature monazite structure type to the baryte structure type. The phase transition, close to the temperatures reported for the β to γ phase modifications, is first order and is accompanied by a change in volume of −1.6%. The crystal structure of this phase has been refined using the Rietveld method to agreement factors of Rp = 0.018, Rwp = 0.019, Rp = 0.011. No evidence for premonitory behaviour was found in the temperature dependence of the monoclinic lattice constants rom 873 K to 1063 K and these have been used to determine the thermal expansion tensor of crocoite just below the phase transition. At 1000 K the magnitudes of the tensor coefficients are α11, 2.66(1) × 10−5 K−1; α22, 2.04(1) × 10−5 K−1; α33, 4.67(4) × 10−5 K−1; and α13, −1.80(2) × 10−5 K−1 using the IRE convention for the orientation of the tensor basis. The orientation of the principal axes of the thermal expansion tensor are very close to those reported previously for the temperature range 50–300 K.

The preparation and characterisation of Sb3Cl11F4

1977 ◽  
Vol 55 (5) ◽  
pp. 743-748 ◽  
Author(s):  
Jack G. Ballard ◽  
Thomas Birchall ◽  
David R. Slim
Keyword(s):  
Crystal Structure ◽  
Title Compound ◽  
Mössbauer Spectra ◽  
Three Dimensional ◽  
Chlorine Atoms ◽  
Space Group ◽  
X Ray ◽  
Mossbauer Spectra ◽  
Final Agreement

The title compound has been prepared by the reaction of SbF5 and SbCl5 in liquid SO2. Raman and Mössbauer spectra have been recorded and its crystal structure determined by three-dimensional X-ray counter measurements. Crystals are monoclinic with a = 12.359(6) Å, b = 16.480(10) Å, c = 9.387(3) Å, β = 103.96(5)°. The structure has been refined in the space group P21/n to a final agreement index R2 of 0.113 for 2415 independent reflections. The structure consists of a cis fluorine-bridged trimer with one of the chlorine atoms 25% substituted by fluorine.

Polymere Dimethyl-und Diphenylglyoximatokomplexe des Cobalts und Eisens mit Pyrazin als Brückenligand. Die Kristallstruktur des Bis(dimethylglyoximato)pyrazin-cobalt(II) + / Polymeric Dimethyl-and Diphenylglyoximato Complexes of Cobalt and Iron with Pyrazine as a Bridging Ligand. The Crystal Structure of Bis(dimethylglyoximato)pyrazine Cobalt(II)+

1981 ◽  
Vol 36 (4) ◽  
pp. 441-446 ◽  
Author(s):  
Frank Kübel ◽  
Joachim Strähle
Keyword(s):  
Crystal Structure ◽  
Mössbauer Spectra ◽  
Local Symmetry ◽  
Space Group ◽  
Mossbauer Spectra ◽  
Bridging Ligand ◽  
Linear Chains ◽  
Square Planar ◽  
Fe Complexes

Abstract Polymeric bis(dimethyl-and diphenylglyoximato)-complexes of Fe(II) and Co(II) with pyrazine as a bridging ligand have been synthesized. The Co(II) complexes are para-magnetic with μ = 1.83 B.M., and surprisingly stable against oxidation. Bis (dimethyl-glyoximato)pyrazine-cobalt (II) crystallizes monoclinic in the space group C2/m with Z = 2. The crystal structure shows linear chains of alternating Co atoms and pyrazine ligands. Perpendicular to the chain, the Co atoms are coordinated in a square planar arrangement by two dimethylglyoximato ligands (Co-N= 189 pm), the local symmetry being C2h-The long Co-pyrazine distance of 224 pm is in agreement with the fact that the compound is a 19 electron complex. The Co complexes do not have conducting properties. The Fe(II) complexes possess the same structure but with stronger bonds in the chain. They show very low conductivity of approximately 10-10 cm -1 Ω-1 . The Mössbauer spectra of the Fe-complexes are reported.

Crystal Structure, Mössbauer Spectra, and Thermal Behavior of H2Fe(CO)2[P(OPh)3]2

2001 ◽  
Vol 40 (11) ◽  
pp. 2628-2630 ◽  
Author(s):  
Vladimir Arion ◽  
Jean-Jacques Brunet ◽  
Denis Neibecker
Keyword(s):  
Crystal Structure ◽  
Thermal Behavior ◽  
Mössbauer Spectra ◽  
Mossbauer Spectra
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