On the composition of delafossite

1968 ◽  
Vol 36 (281) ◽  
pp. 643-650 ◽  
Author(s):  
H. Wiedersich ◽  
J. W. Savage ◽  
A. H. Muir ◽  
D. G. Swarthout
Keyword(s):  
Solid State ◽  
Isomer Shift ◽  
Solid State Reaction ◽  
Mössbauer Effect ◽  
Mossbauer Effect ◽  
Stable Compound ◽  
X Ray ◽  
Mössbauer Isomer Shift ◽  
Approximate Composition ◽  
Chemical Techniques

SummaryOxides of the Cu-Fe-O system prepared by solid-state reaction methods have been investigated by X-ray, Mössbauer effect, and analytical chemical techniques. In agreement with most previous investigations of this system, it is found that CuFeO2 exists as a stable compound, and that the mineral delafossite has essentially this composition. These results are in disagreement with those of Buist, Gadalla, and White who propose that delafossite has an approximate composition Cu6Fe3O7 instead of CuFeO2. In fact, a compound of composition Cu6F3O7 could not be prepared. The Mössbauer isomer shift provides confirmation that the iron in CuFeO2 is trivalent.

A study of quasi-crystalline Al–Fe alloys by Mössbauer-effect spectroscopy and diffraction techniques

1987 ◽  
Vol 65 (10) ◽  
pp. 1301-1308 ◽  
Author(s):  
F. van der Woude ◽  
P. J. Schurer
Keyword(s):  
Isomer Shift ◽  
Quadrupole Splitting ◽  
Mössbauer Effect ◽  
Basis Vector ◽  
Mossbauer Effect ◽  
X Ray ◽  
Mössbauer Effect Spectroscopy ◽  
Fe Alloys ◽  
Quasi Crystals ◽  
Mackay Cluster

After an introduction to quasi crystals, special attention is paid to icosahedral Al6(Cr0.7Fe0.3) and decagonal Al7(Mn1−xFex)2. These alloys have been studied with Mössbauer-effect spectroscopy and diffraction techniques. Isomer-shift and quadrupole-splitting data on the icosahedral alloys are successfully described with a Mackay cluster. The X-ray diffractogram of pure decagonal Al7(Mn1−xFex)2, x = 0 and 0.3, has been indexed with a basis-vector set that is closely related to the icosahedral set.

MÖSSBAUER EFFECT STUDY OF THE EU-Y-Ba-Cu-O SUPERCONDUCTOR

1987 ◽  
Vol 01 (02) ◽  
pp. 491-494
Author(s):  
Weiming Xu ◽  
Xiaoxiang Liu ◽  
Mingzhi Jin ◽  
Lanying He ◽  
Yifeng Wang ◽  
...  
Keyword(s):  
Isomer Shift ◽  
Mössbauer Effect ◽  
Single Phase ◽  
Hyperfine Interactions ◽  
Effect Study ◽  
X Ray Diffraction ◽  
Mossbauer Effect ◽  
X Ray ◽  
Zero Resistance ◽  
The Eu

In this work the hyperfine interactions of (EuxY1−x)0.3Ba0.1CuO3(x=0.5, 0.7, 1.0) superconductors have been studied by 151Eu Mössbauer effect. X-ray diffraction shows that the materials are of single phase. Mössbauer spectra were measured at 300K and 83K. The results show that Eu ions are in the trivalent oxidation state. The isomer shift decreases with the increasing of composition x. The electron density at the 151Eu nuclei is decreased below the zero resistance temperature.

X-ray Structure Refinement and Vibrational Spectroscopy of Ca8Gd2 (PO4)6 O2

2013 ◽  
Vol 12 (10) ◽  
pp. 719-726
Author(s):  
R. Ayadi ◽  
Mohamed Boujelbene ◽  
T. Mhiri
Keyword(s):  
Solid State ◽  
General Formula ◽  
Vibrational Spectroscopy ◽  
Powder Diffraction ◽  
Infrared Spectra ◽  
Solid State Reaction ◽  
Structure Refinement ◽  
Unit Cell ◽  
Cell Group ◽  
X Ray

The present paper is interested in the study of compounds from the apatite family with the general formula Ca10 (PO4)6A2. It particularly brings to light the exploitation of the distinctive stereochemistries of two Ca positions in apatite. In fact, Gd-Bearing oxyapatiteCa8 Gd2 (PO4)6O2 has been synthesized by solid state reaction and characterized by X-ray powder diffraction. The site occupancies of substituents is0.3333 in Gd and 0.3333 for Ca in the Ca(1) position and 0. 5 for Gd in the Ca (2) position.  Besides, the observed frequencies in the Raman and infrared spectra were explained and discussed on the basis of unit-cell group analyses.

scholarly journals NOTIZEN. Weitere Verbindungen vom Typ A3NO3: K3NO3 und Rb3NO3 / Further Compounds Typ A3NO3: K3NO3 and Rb3NO3

1980 ◽  
Vol 35 (2) ◽  
pp. 237-238 ◽  
Author(s):  
Martin Jansen
Keyword(s):  
Solid State ◽  
Crystal Structures ◽  
Solid State Reaction ◽  
X Ray

Abstract K3NO3 and RbsNO3 were prepared by solid state reaction of equimolar mixtures of K2O/KNO2 and Rb20/RbN02, respectively. According to X-ray powder photographs their crystal structures are derived from the perovs-kite structure. K3NO3 is isostructural with Na3NO3 (a = 521.7 pm, Z = 1), Rb3NO3 represents a tetragonally distorted variant with a = 770.5, c = 550.8 pm and Z = 2.

scholarly journals X-ray and237Np Mössbauer effect investigation on the NpB2C compound

2010 ◽  
Vol 217 ◽  
pp. 012140 ◽  
Author(s):  
P Gaczynski ◽  
P Rogl ◽  
E Colineau ◽  
R Eloirdi ◽  
F Wastin ◽  
...  
Keyword(s):  
Mössbauer Effect ◽  
Mossbauer Effect ◽  
X Ray

Preparation of Ultra–Fine La3NbO7 Powder by Solid State Reaction

2012 ◽  
Vol 512-515 ◽  
pp. 158-161 ◽  
Author(s):  
Ling Dai ◽  
Qiang Xu ◽  
Shi Zhen Zhu ◽  
Ling Liu
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Single Phase ◽  
Thermal Barrier ◽  
X Ray Diffraction ◽  
X Ray ◽  
Granular Particle ◽  
Fine Particle Size ◽  
Ultra Fine Particle ◽  
Different Temperatures

As a new candidate material for the ceramic layer in thermal barrier coatings (TBCs) system, La3NbO7 was synthesized with La2O3 powder and Nb2O5 powder by solid state reaction. The stating powders with a mole ratio of La to Nb of 3:1 were mixed and then the mixture was calcined under the different temperatures(800°C, 1000°C, 1200°C) and dwell times(2h, 6h, 10h). The phase structure of the powder was observed by X–ray diffraction(XRD), and the microstructure of the sample was observed by scanning electron microscope(SEM). The effect of calcination temperature and dwell Time on the phase formation were examined. The results indicate that the La3NbO7 powder with single phase can be synthesized successfully at 1200°C for 10h in air, and the La3NbOsub>7 powders synthesized have an ultra-fine particle size of 0.5˜1µm with a granular particle shape. With the temperature increasing, LaNbO4/sub> was synthesized firstly and then La3NbO7 was synthesized with a mole ratio of La2O3 to LaNbO4 of 1:1.

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