CONSTRUCTING PHASE DIAGRAMS FOR SILICATE MINERALS IN EQUILIBRIUM WITH AN AQUEOUS PHASE

Soil Science ◽  
1992 ◽  
Vol 153 (1) ◽  
pp. 5-12 ◽  
Author(s):  
CHANDRIKA VARADACHARI
Keyword(s):  
Phase Diagrams ◽  
Aqueous Phase ◽  
Silicate Minerals

Selected aqueous phase diagrams of condensed phosphate systems

1968 ◽  
Vol 13 (2) ◽  
pp. 145-148 ◽  
Author(s):  
E. J. Griffith ◽  
R. L. Buxton
Keyword(s):  
Phase Diagrams ◽  
Aqueous Phase ◽  
Condensed Phosphate

Thermodynamic calculation of aqueous phase diagrams

2017 ◽  
Vol 149 (2) ◽  
pp. 395-409 ◽  
Author(s):  
Arthur D. Pelton ◽  
Gunnar Eriksson ◽  
Klaus Hack ◽  
Christopher W. Bale
Keyword(s):  
Phase Diagrams ◽  
Aqueous Phase ◽  
Thermodynamic Calculation

Aqueous phase diagrams containing oxalic acid at 303.15 K

1997 ◽  
Vol 134 (1-2) ◽  
pp. 201-211 ◽  
Author(s):  
Norma Barnes ◽  
Mónica Gramajo de Doz ◽  
Horacio N. Sólimo
Keyword(s):  
Oxalic Acid ◽  
Phase Diagrams ◽  
Aqueous Phase

Transmission electron microscope studies in special ceramics

1978 ◽  
Vol 36 (1) ◽  
pp. 268-269
Author(s):  
A. Zangvil ◽  
L.J. Gauckler ◽  
G. Schneider ◽  
M. Rühle
Keyword(s):  
Phase Diagrams ◽  
Crystal Structures ◽  
Thin Foil ◽  
Limited Extent ◽  
Complex Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
Lattice Resolution

The use of high temperature special ceramics which are usually complex materials based on oxides, nitrides, carbides and borides of silicon and aluminum, is critically dependent on their thermomechanical and other physical properties. The investigations of the phase diagrams, crystal structures and microstructural features are essential for better understanding of the macro-properties. Phase diagrams and crystal structures have been studied mainly by X-ray diffraction (XRD). Transmission electron microscopy (TEM) has contributed to this field to a very limited extent; it has been used more extensively in the study of microstructure, phase transformations and lattice defects. Often only TEM can give solutions to numerous problems in the above fields, since the various phases exist in extremely fine grains and subgrain structures; single crystals of appreciable size are often not available. Examples with some of our experimental results from two multicomponent systems are presented here. The standard ion thinning technique was used for the preparation of thin foil samples, which were then investigated with JEOL 200A and Siemens ELMISKOP 102 (for the lattice resolution work) electron microscopes.

Electron energy-loss near-edge structure in silicate minerals

1992 ◽  
Vol 50 (2) ◽  
pp. 1258-1259
Author(s):  
D W McComb ◽  
R S Payne ◽  
P L Hansen ◽  
R Brydson
Keyword(s):  
Solid State ◽  
Energy Loss ◽  
Electron Energy ◽  
State Energy ◽  
Local Environment ◽  
Edge Structure ◽  
Silicate Minerals ◽  
Two Samples ◽  
Electron Energy Loss ◽  
Careful Processing

Electron energy-loss near-edge structure (ELNES) is an effective probe of the local geometrical and electronic environment around particular atomic species in the solid state. Energy-loss spectra from several silicate minerals were mostly acquired using a VG HB501 STEM fitted with a parallel detector. Typically a collection angle of ≈8mrad was used, and an energy resolution of ≈0.5eV was achieved.Other authors have indicated that the ELNES of the Si L2,3-edge in α-quartz is dominated by the local environment of the silicon atom i.e. the SiO4 tetrahedron. On this basis, and from results on other minerals, the concept of a coordination fingerprint for certain atoms in minerals has been proposed. The concept is useful in some cases, illustrated here using results from a study of the Al2SiO5 polymorphs (Fig.l). The Al L2,3-edge of kyanite, which contains only 6-coordinate Al, is easily distinguished from andalusite (5- & 6-coordinate Al) and sillimanite (4- & 6-coordinate Al). At the Al K-edge even the latter two samples exhibit differences; with careful processing, the fingerprint for 4-, 5- and 6-coordinate aluminium may be obtained.

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