Application of the Mössbauer Effect to Investigation of the Solid State Reaction of Iron(II) Sulfate with Potassium Cyanide

1969 ◽  
Vol 8 (8) ◽  
pp. 600-600 ◽  
Author(s):  
P. Gütlich ◽  
K. M. Hasselbach
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Mössbauer Effect ◽  
Potassium Cyanide ◽  
Mossbauer Effect

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.

The wustite-spinel interface

1987 ◽  
Vol 45 ◽  
pp. 268-269
Author(s):  
S.R. Summerfelt ◽  
C.B. Carter
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Strain Energy ◽  
Matrix Material ◽  
Lattice Misfit ◽  
Solid State Reactions ◽  
Oxygen Sublattice ◽  
Large Particles ◽  
Small Lattice ◽  
Coherent Interfaces

The wustite-spinel interface can be viewed as a model interface because the wustite and spinel can share a common f.c.c. oxygen sublattice such that only the cations distribution changes on crossing the interface. In this study, the interface has been formed by a solid state reaction involving either external or internal oxidation. In systems with very small lattice misfit, very large particles (>lμm) with coherent interfaces have been observed. Previously, the wustite-spinel interface had been observed to facet on {111} planes for MgFe2C4 and along {100} planes for MgAl2C4 and MgCr2O4, the spinel then grows preferentially in the <001> direction. Reasons for these experimental observations have been discussed by Henriksen and Kingery by considering the strain energy. The point-defect chemistry of such solid state reactions has been examined by Schmalzried. Although MgO has been the principal matrix material examined, others such as NiO have also been studied.

Observation of solid-state reaction between a thin yttria film and a (0001) α-alumina substrate

1994 ◽  
Vol 52 ◽  
pp. 644-645
Author(s):  
J. R. Heffelfinger ◽  
C. B. Carter
Keyword(s):  
Electron Microscopy ◽  
Solid State ◽  
Solid State Reaction ◽  
Yttrium Aluminum Garnet ◽  
Secondary Phase ◽  
Ceramic Composites ◽  
Alumina Substrate ◽  
Transmission Electron ◽  
Alumina Fibers ◽  
Optical Applications

Transmission-electron microscopy (TEM), scanning-electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDS) were used to investigate the solid-state reaction between a thin yttria film and a (0001) α-alumina substrate. Systems containing Y2O3 (yttria) and Al2O3 (alumina) are seen in many technologically relevant applications. For example, yttria is being explored as a coating material for alumina fibers for metal-ceramic composites. The coating serves as a diffusion barrier and protects the alumina fiber from reacting with the metal matrix. With sufficient time and temperature, yttria in contact with alumina will react to form one or a combination of phases shown by the phase diagram in Figure l. Of the reaction phases, yttrium aluminum garnet (YAG) is used as a material for lasers and other optical applications. In a different application, YAG is formed as a secondary phase in the sintering of AIN. Yttria is added to AIN as a sintering aid and acts as an oxygen getter by reacting with the alumina in AIN to form YAG.

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