Corkite from Aggeneys, Bushmanland, South Africa

1990 ◽  
Vol 54 (377) ◽  
pp. 603-608 ◽  
Author(s):  
H. de Bruiyn ◽  
W. A. Van Der Westhuizen ◽  
G. J. Beukes ◽  
T. Q. Meyer
Keyword(s):  
Solid Solution ◽  
General Formula ◽  
Regional Distribution ◽  
The Other ◽  
Iron Formation ◽  
Charge Balance ◽  
X Ray Diffraction ◽  
Broken Hill ◽  
Complete Solid Solution ◽  
End Members

AbstractCorkite associated with plumbojarosite and goethite occurs in gossan and iron-formation at Black Mountain and Broken Hill, Aggeneys. Electron microprobe analyses indicate that there are two groups of corkite present in the area; one with high Cu and low (PO4)3− and the other with low Cu and high (PO and the other with low Cu and high (PO4)3− contents. This can be explained in terms of the general formula contents. This can be explained in terms of the general formula AB2(XO4)2(OH)6, where the incorporation of divalent ions in the B site is accompanied by the exchange of trivalent anions by divalent ones to retain charge balance. Complete solid-solution is inferred between (SO4)2−and (PO4)3− end members, indicating that the jarosite and beudantite groups form part of the same solid-solution series. The distribution of Zn in corkite also reflects the regional distribution of zinc grades in the area, becoming more zinc-rich from west to east. New X-ray diffraction parameters are also presented which update existing data.

Marshite–miersile solid solution and iodargyrite from Broken Hill, New South Wales, Australia

1998 ◽  
Vol 62 (04) ◽  
pp. 471-475 ◽  
Author(s):  
P. W. Millsteed
Keyword(s):  
Solid Solution ◽  
Limit Of Detection ◽  
New South ◽  
Cell Parameters ◽  
Cu Content ◽  
Broken Hill ◽  
South Wales ◽  
Complete Solid Solution ◽  
Vegard’S Law ◽  
End Members

Abstract Microprobe analysis of marshite and miersite from Broken Hill, Australia, demonstrate extensive solid solution between the end-members CuI and AgI, indicating the possibility of a complete solid-solution series. Unit-cell parameters increase from 6.054 Å for marshite to 6.504 Å for miersite, closely following Vegard's Law. The Cu content of iodargyrite is generally below the limit of detection, but one zoned crystal contained 0.28 wt.% Cu. Crystallization of either miersite or iodargyrite at Broken Hill appears to be dependent upon the local availability and ratio of copper, silver and iodine ions.

Compression and Compressibility Studies of Plutonium and a Plutonium-Gallium Alloy

1980 ◽  
Vol 24 ◽  
pp. 221-230 ◽  
Author(s):  
R. B. Roof
Keyword(s):  
Solid Solution ◽  
The Other ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metal Foils ◽  
Gallium Alloy

Two metal foils, one pure plutonium and the other being a solid solution of 6.5 a/o gallium In plutonium, were examined, in-situ, by X-ray diffraction techniques while under pressure. The purpose was to determine the compression and compressibility of these materials as a function of pressure and to identify the products of any transformation that may occur due to the action of applied pressures.

An Approach to the Solid Solution Problem Using a Computerized Identification Technique

1969 ◽  
Vol 13 ◽  
pp. 539-549
Author(s):  
Gerald G. Johnson ◽  
Frank L. Chan
Keyword(s):  
Solid Solution ◽  
Powder Diffraction ◽  
Lattice Parameter ◽  
Powder Diffraction File ◽  
X Ray ◽  
Complete Solid Solution ◽  
Vegard’S Law ◽  
Identification Technique ◽  
Approximate Composition ◽  
End Members

Since for most real systems, solid solution effects influence the position and intensity of the x-ray powder diffraction pattern, it is desirable and necessary to have an automatic system which will identify standard reference phases regardless of the amount of solid solution. Using the system CdS-ZnS, where the lattice parameter a0 changes from 4.136 to 3.820Å, with complete solid solution over the entire range of composition, an illustrative study was made. This work presents the results obtained from a computer analysis of the powder pattern obtained. It has been found that if the starting chemistry is known and the end members of the series are in the ASTM Powder Diffraction File, that the solid solution can be identified. Once the phases present are identified, a plot following Vegard's law yields the approximate composition of the sample under consideration. These two methods of compositional determination agree quite well. Examples of the computer system and description of the program input and output with interpretation of the results will be discussed.

Effect of Gallium Oxide on Phase Assemblage in Apatite and Whitlockite Hosts for Waste Immobilization

2008 ◽  
Vol 1107 ◽  
Author(s):  
Lee. A. Gerrard ◽  
Shirley. K. Fong ◽  
Brian. L. Metcalfe ◽  
Ian. W. Donald
Keyword(s):  
Solid Solution ◽  
Gallium Oxide ◽  
Phase Assemblage ◽  
X Ray Diffraction ◽  
Apatite Phase ◽  
Complete Solid Solution ◽  
Total Phase ◽  
Simulated Waste ◽  
Lower Temperature ◽  
Gallium Phosphate

AbstractTo immobilize halide and actinide ions present in specific ILW waste a process has been developed that uses mineral phases as the host material. The mechanism of substitution of gallium into these phases will have a large effect on the phase assemblage. This will inevitably affect the total amount of halide that can be immobilized in to total phase mixture.The full simulated waste stream composition containing varying concentrations (1–40 wt.%) of gallium oxide was studied. Also nominal compositions for gallium doped fluorapatites (Ca10-1.5xGax)F2(PO4)6 (x = 0, 0.25, 0.5, 0.75, 1.0) and gallium doped whitlockites Ca9Gay(PO4)6+y (x = 0.2, 0.4, 0.6, 0.8, 1.0) were prepared at 750–1050 °C.These were studied by powder x-ray diffraction (XRD) to determine the phase assemblage and solid solution limits of gallium in the apatite and whitlockite phases. It was found that a complete solid solution was formed between whitlockite, Ca3(PO4)2, and Ca9Gay(PO4)6+y. In the nominal apatite compositions it was found that gallium did not substitute into the apatite structure but was instead partitioned over Ca9Gay(PO4)6+y, gallium phosphate, and unreacted gallium oxide. At higher temperatures gallium suppressed the formation of the apatite phase and was largely partitioned into the Ca9Gay(PO4)6+y phase whereas at lower temperature the majority was present as unreacted Ga2O3. In the full DCHP compositions it was found that gallium is likely to be partitioned over a number of phases including apatite, cationdoped whitlockite and gallium phosphate.

Glass-Coated Cu-Mn-Ga Microwires Produced by Taylor-Ulitovsky Technique

2009 ◽  
Vol 152-153 ◽  
pp. 79-84 ◽  
Author(s):  
Joan Josep Suñol ◽  
L. Escoda ◽  
C. García ◽  
V.M. Prida ◽  
Victor Vega ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Solid Solution ◽  
Curie Temperature ◽  
Energy Dispersive Spectroscopy ◽  
Room Temperature ◽  
Alloy Composition ◽  
The Other ◽  
X Ray Diffraction ◽  
X Ray ◽  
Low Magnetic Field

Glass-coated Cu-Mn-Ga microwires were fabricated by Taylor-Ulitovsky technique. By means of energy dispersive spectroscopy microanalysis, an average alloy composition of Cu56Ga28Mn16 was determined. The temperature dependence of magnetization measured at a low magnetic field showed the coexistence of two ferromagnetic phases. The Curie temperature of one phase is 125 K and above room temperature for the other one. X-ray diffraction at room temperature and at 100 K reflects the presence of the same three crystalline phases corresponding to the cubic B2 Cu-Mn-Ga structure as a main phase and the minor phases of fcc Cu rich solid solution with Mn and Ga and the monoclinic CuO.

scholarly journals Caracterização metalúrgica de ligas de Ni-Cr para metalocerimica

2021 ◽  
Vol 40 (1) ◽  
pp. 57-59
Author(s):  
Carlos Ariel Samudio Perez ◽  
Cezar Augusto Garbin
Keyword(s):  
Solid Solution ◽  
Diffraction Analysis ◽  
The Other ◽  
Secondary Phases ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hardness Tests ◽  
Density Values ◽  
Cubic Structure ◽  
Hardness Values

Alternative Ni-Cr alloys applied in dentistry of two commercial brands for ceramometal restoration were evaluated. The alloys were analyzed in the commercial and after casting conditions using experimental techniques of metallography, X-ray diffraction, superficial hardness and density. The metalografics and X-ray diffraction analysis showed that, the alloys microstructure is marked with the presence of a solid solution having an ordered face- centred cubic structure, Ni-rich austenitic (y phase) matrix, and with fine precipitates particles of secondary phases. The Vicker hardness tests showed a decrease in hardness values of the studied alloys aer casting. The alloys density values, on the other hand, did not manifest changes.

Crystal chemistry of danalite from Daba Shabeli Complex (N Somalia)

1996 ◽  
Vol 60 (399) ◽  
pp. 375-379 ◽  
Author(s):  
P. Nimis ◽  
G. Molin ◽  
D. Visonà
Keyword(s):  
General Formula ◽  
Crystal Chemistry ◽  
The Other ◽  
The World ◽  
Alkali Granites ◽  
End Members ◽  
Host Rocks

Danalite is the Fe2+ end-member of the minerals of the helvite group, which have the general formula M8(BeSiO4)6S2, with M = (Mn,Fe2+,Zn). These minerals are relatively uncommon, although limited amounts are known at many localities round the world (e.g. Ragu, 1994; Larsen, 1988; Kwak and Jackson, 1986, and references therein). Their typical host rocks are skams, but occurrences in mineralized veins pegmatites, and altered alkali granites have also been reported. Danalite is rarer than helvite (Mn endmember) and genthelvite (Zn end-member) and, unlike the other two end-members, has never been found nor synthesized as a pure mineral (Mel'nikov et al., 1968).

A reexamination of the turquoise group: the mineral aheylite, planerite (redefined), turquoise and coeruleolactite

1998 ◽  
Vol 62 (1) ◽  
pp. 93-111 ◽  
Author(s):  
Eugene E. Foord ◽  
Joseph E. Taggart
Keyword(s):  
Solid Solution ◽  
General Formula ◽  
Direct Determination ◽  
Chemical Analyses ◽  
Maximum Dimension ◽  
Complete Solid Solution ◽  
Pale Green ◽  
Site Vacancy

AbstractThe turquoise group has the general formula:A0–1B6(PO4)4−x(PO3OH)x(OH)8.4H2O, wherex= 0–2, and consists of six members: planerite, turquoise, faustite, aheylite, chalcosiderite and an unnamed Fe2+-Fe3+analogue. The existence of ‘coeruleolactite’ is doubtful. Planerite is revalidated as a species and is characterized by a dominantA-site vacancy. Aheylite is established as a new member of the group, and is characterized by having Fe2+dominant in theA-site.Chemical analyses of 15 pure samples of microcrystalline planerite, turquoise, and aheylite show that a maximum of two of the (PO4) groups are protonated (PO3OH) in planerite. Complete solid solution exists between planerite and turquoise. Other members of the group show variableA-site vacancy as well. Most samples of ‘turquoise’ are cation-deficient or are planerite. Direct determination of water indicates that there are 4 molecules of water.Planerite, ideally ☐Al6(PO4)2(PO3OH)2(OH)8.4H2O, is white, pale blue or pale green, and occurs as mamillary, botryoidal crusts as much as several mm thick; may also be massive; microcrystalline, crystals typically 2–4 micrometres, luster chalky to earthy, H. 5, somewhat brittle, no cleavage observed, splintery fracture, Dm2.68(2), Dc2.71, not magnetic, not fluorescent, mean RI about 1.60.a7.505(2),b9.723(3),c7.814(2) Å, α 111.43°, β 115.56°, γ 68.69°, V 464.2(1) Å3, Z = 1.Aheylite, ideally Fe2+Al6(PO4)4(OH)8.4H2O, is pale blue or green, and occurs as isolated and aggregate clumps of hemispherical or spherical, radiating to interlocked masses of crystals that average 3 micrometres in maximum dimension; porcelaneous-subvitreous luster, moderate to brittle tenacity, no cleavage observed, hackly to splintery fracture, not magnetic, not fluorescent, biax. (+), mean RI is about 1.63, Dm2.84(2), Dc2.90.a7.400(1),b9.896(1),c7.627(1) Å, α 110.87°, β 115.00°, γ 69.96°, V 460.62(9) Å3, Z = 1.

The solid solution between platinum and palladium in nature

2013 ◽  
Vol 77 (3) ◽  
pp. 269-274 ◽  
Author(s):  
L. Bindi ◽  
F. Zaccarini ◽  
G. Garuti ◽  
N. Angeli
Keyword(s):  
Solid Solution ◽  
Single Crystal ◽  
Structural Data ◽  
Micro Hardness ◽  
Metallic Elements ◽  
X Ray Diffraction ◽  
X Ray ◽  
Complete Solid Solution ◽  
Hardness Values ◽  
Palladium Platinum

AbstractChemical and structural data are reported for platinum–palladium intermediates from two nuggets found at Córrego Bom Sucesso, Minas Gerais, Brazil. Three grains with simple stoichiometries (i.e. PtxPd1−x with x ∼0.67, ∼0.5 and ∼0.33, which correspond to Pt2Pd, PtPd and PtPd2, respectively) were characterized by single-crystal X-ray diffraction and electron-probe microanalysis. In the absence of single-crystal data it might be tempting to hypothesize that such simple stoichiometries represent distinct mineral species, however structural analyses show that all of the phases are cubic and crystallize in space group Fmm. They are, therefore, natural intermediates in the palladium–platinum solid solution. Reflectance and micro-hardness values are reported for the samples and a comparison with the pure metallic elements made. On the basis of information gained from the chemical and structural characterization it can be concluded that there is a complete solid solution between Pt and Pd in nature. These findings corroborate results from experiments on synthetic compounds.

Study of Aluminium-Titanate Based Ceramics in Fe2O3-Al2O3-TiO2 System

2010 ◽  
Vol 659 ◽  
pp. 31-36
Author(s):  
Támas Korim
Keyword(s):  
Heat Treatment ◽  
Solid Solution ◽  
Lattice Parameter ◽  
Self Healing ◽  
X Ray Diffraction ◽  
Repeated Heating ◽  
X Ray ◽  
Aluminium Titanate ◽  
Complete Solid Solution ◽  
Constructed Self

Solid solutions formed within the Al2O3-TiO2-Fe2O3 (Fe2xAl2(1-x)TiO5) system upon heat treatment were investigated by adjusting the substituting Fe3+ content in the range of x=0.0 to 1.0. X-ray diffraction phase analyses and lattice parameter determinations confirmed that substitution of Fe3+ ions within the aluminium titanate lattice was complete. For this complete solid solution, however, the trends observed for changes in d-spacing values indicated that there were certain discrete compositions to identify with Fe3+ substitution. Within these, Fe0.4Al1.6TiO5 and Fe1.6Al0.4TiO5 crystalline phases were investigated in detail and their X-ray diffraction cards were constructed. Self-healing effect occurring in repeated heating-cooling cycles in Fe3+ doped AT ceramics were proved; it was demonstrated that Fe3+ doped AT ceramics do not decompose even if exposed to repeated thermal shock.

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