scholarly journals Absence of solid solution between Fe(II) and Mg(II) hydroxides and consequences on formation of fougerite and smectites

2019 ◽  
Vol 98 ◽  
pp. 04003
Author(s):  
Guilhem Bourrié ◽  
Jihaine Ben Nacib ◽  
Georges Ona-Nguema ◽  
Fabienne Trolard
Keyword(s):  
Solid Solution ◽  
Aqueous Solution ◽  
Solid Solutions ◽  
Electric Charge ◽  
Ionic Radii

As there exists extended solid solutions between ferrous and magnesian silicates, experiments were conducted to check if ferrous and magnesian hydroxides can co-precipitate in a solid solution. Results show that no solid solution forms and instead Fe(II) and Mg(II) hydroxides precipitate separately with the same solubilities as pure components. However, in fougerite, F(III), Fe(II) and Mg(II) coexist in a brucitic type hydroxide, with an extended solid solution. This implies that fougerite formation results from Fe(III) precipitation, Fe(III) being surrounded by divalent Fe(II) and Mg(II) to comply with the exclusion rule: Fe(III) ions cannot be direct neighbours. Consequently, Fe(III) - Fe(II) - Mg(II) smectites cannot form by oxidation of a ferrous magnesian brucitic layer, but by silication of fougerite. The impossibility of formation of a solid solution between Fe(II) hydroxide and Mg(II) hydroxide, while their electric charge and ionic radii are identical can be explained by the differences of electronegativities of the elements. Fe(II) and Mg(II) can dimerize separately in aqueous solution, but an heterodimer cannot form.

THE EFFECT OF A FOREIGN SUBSTANCE ON THE TRANSITION: NH4NO3IVNH4NO3 III

1946 ◽  
Vol 24b (4) ◽  
pp. 93-108 ◽  
Author(s):  
Alan N. Campbell ◽  
A. Jean R. Campbell
Keyword(s):  
Solid Solution ◽  
Aqueous Solution ◽  
Ammonium Nitrate ◽  
Solid Solutions ◽  
Potassium Nitrate ◽  
Mixed Aqueous Solution ◽  
Foreign Substance

It is shown that the above transition can be repressed (metastably) by using in place of pure ammonium nitrate a solid solution of potassium nitrate in ammonium nitrate. With such a solid solution containing 8 to 10% potassium nitrate, the temperature of the transition III → IV is depressed to about −20 °C. Such solid solutions can be prepared either by fusing the components together or by crystallizing from a mixed aqueous solution.

Solid-solute phase equilibria in aqueous solution: Fundamentals and applications

2013 ◽  
Vol 85 (11) ◽  
pp. 2089-2095 ◽  
Author(s):  
Erich Königsberger
Keyword(s):  
Solid Solution ◽  
Aqueous Solution ◽  
Phase Equilibria ◽  
Solid Solutions ◽  
Thermodynamic Models ◽  
Equilibria In Aqueous Solution

The importance of solid-solution–aqueous-solution (SSAS) equilibria requires the incorporation of solid solutions into thermodynamic models for industrially and environmentally relevant applications. Insights from appropriate measurements and recent database developments have made such extensions feasible. Examples illustrating various types of stable and metastable equilibria involving solid solutions will be given.

scholarly journals Synthesis of Ce1−xPdxO2−δ Solid Solution in Molten Nitrate

Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 640
Author(s):  
Hideaki Sasaki ◽  
Keisuke Sakamoto ◽  
Masami Mori ◽  
Tatsuaki Sakamoto
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Solid Solutions ◽  
Photoelectron Spectroscopy ◽  
Synthesis Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Co Precipitation ◽  
Ionic States

CeO2-based solid solutions in which Pd partially substitutes for Ce attract considerable attention, owing to their high catalytic performances. In this study, the solid solution (Ce1−xPdxO2−δ) with a high Pd content (x ~ 0.2) was synthesized through co-precipitation under oxidative conditions using molten nitrate, and its structure and thermal decomposition were examined. The characteristics of the solid solution, such as the change in a lattice constant, inhibition of sintering, and ionic states, were examined using X-ray diffraction (XRD), scanning electron microscopy–energy-dispersive X-ray spectroscopy (SEM−EDS), transmission electron microscopy (TEM)−EDS, and X-ray photoelectron spectroscopy (XPS). The synthesis method proposed in this study appears suitable for the easy preparation of CeO2 solid solutions with a high Pd content.

Electron microprobe study of turquoise-group solid solutions in the Neyshabour and Meydook mines, northeast and southern Iran

2020 ◽  
Vol 58 (1) ◽  
pp. 71-83
Author(s):  
Elahe Mansouri Gandomani ◽  
Nematollah Rashidnejad-Omran ◽  
Amir Emamjomeh ◽  
Pietro Vignola ◽  
Tahereh Hashemzadeh
Keyword(s):  
Solid Solution ◽  
Solid Solutions ◽  
Electron Microprobe ◽  
Electron Probe Microanalysis ◽  
Electron Probe ◽  
Major Elements ◽  
Point Of View ◽  
Chemical Compositions ◽  
Light Blue ◽  
Quaternary Solid Solution

ABSTRACT Turquoise, CuAl6(PO4)4(OH)8·4H2O, belongs to the turquoise group, which consists of turquoise, chalcosiderite, aheylite, faustite, planerite, and UM1981-32-PO:FeH. In order to study turquoise-group solid solutions in samples from the Neyshabour and Meydook mines, 17 samples were selected and investigated using electron probe microanalysis. In addition, their major elements were compared in order to evaluate the feasibility of distinguishing the provenance of Persian turquoises. The electron microprobe data show that the studied samples are not constituted of pure turquoise (or any other pure endmember) and belong, from the chemical point of view, to turquoise-group solid solutions. In a turquoise–planerite–chalcosiderite–unknown mineral quaternary solid solution diagram, the chemical compositions of the analyzed samples lie along the turquoise–planerite line with minor involvement of chalcosiderite and the unknown mineral. Among light blue samples with varying hues and saturations from both studied areas, planerite is more abundant among samples from Meydook compared with samples from Neyshabour. Nevertheless, not all the light blue samples are planerite. This study demonstrates that distinguishing the deposit of origin for isochromatic blue and green turquoises, based on electron probe microanalysis method and constitutive major elements, is not possible.

Epitaxial Solid-Solution Films of Immiscible MgO and CaO

1994 ◽  
Vol 341 ◽  
Author(s):  
E. S. Hellman ◽  
E. H. Hartford
Keyword(s):  
Solid Solution ◽  
Molecular Beam Epitaxy ◽  
Lattice Constant ◽  
Solid Solutions ◽  
Molecular Beam ◽  
Building Blocks ◽  
Layer Growth ◽  
Growth Mode ◽  
Miscibility Gap ◽  
Layer By Layer

AbstractMetastable solid-solutions in the MgO-CaO system grow readily on MgO at 300°C by molecular beam epitaxy. We observe RHEED oscillations indicating a layer-by-layer growth mode; in-plane orientation can be described by the Matthews theory of island rotations. Although some films start to unmix at 500°C, others have been observed to be stable up to 900°C. The Mgl-xCaxO solid solutions grow despite a larger miscibility gap in this system than in any system for which epitaxial solid solutions have been grown. We describe attempts to use these materials as adjustable-lattice constant epitaxial building blocks

scholarly journals Removal of Chromium from Aqueous Solution Using Modified Pomegranate Peel:Mechanistic and Thermodynamic Studies

2009 ◽  
Vol 6 (s1) ◽  
pp. S153-S158 ◽  
Author(s):  
Tariq S. Najim ◽  
Suhad A. Yassin
Keyword(s):  
Activation Energy ◽  
Solid Solution ◽  
Aqueous Solution ◽  
Adsorption Process ◽  
Batch Process ◽  
The Other ◽  
Water Molecules ◽  
Pomegranate Peel ◽  
Solution Interface ◽  
Adsorbent Surface

Modified pomegranate peel (MPGP) and formaldehyde modified pomegranate peel (FMPGP) were prepared and used as adsorbent for removal of Cr(VI) ions from aqueous solution using batch process. The temperature variation study of adsorption on both adsorbents revealed that the adsorption process is endothermic, from the positive values of ∆H˚. These values lie in the range of physisorption. The negative values of ∆G˚ show the adsorption is favorable and spontaneous. On the other hand, these negative values increases with increase in temperature on both adsorbents, which indicate that the adsorption is preferable at higher temperatures. ∆S˚ values showed that the process is accompanied by increase in disorder and randomness at the solid solution interface due to the reorientation of water molecules and Cr(VI) ions around the adsorbent surface. The endothermic nature of the adsorption was also confirmed from the positive values of activation energy, Ea, the low values of Ea confirm the physisorption mechanism of adsorption. The sticking probability, S*, of Cr(VI) ion on surface of both adsorbents showed that the adsorption is preferable due to low values of S*(0< S*< 1 ), but S*values are lower for FMPGP indicating that the adsorption on FMPGP is more preferable .

Cationic Substitutions in Sphalerite from the Porgera Mine, Papua New Guinea

2021 ◽  
Author(s):  
Christopher H. Ingles ◽  
John A. Mavrogenes
Keyword(s):  
Solid Solution ◽  
Papua New Guinea ◽  
Solid Solutions ◽  
Inductively Coupled Plasma ◽  
New Guinea ◽  
Inductively Coupled ◽  
Cationic Substitution ◽  
Plasma Mass Spectrometry ◽  
Positive Correlations

ABSTRACT Laser ablation-inductively coupled plasma-mass spectrometry was used to traverse hydrothermal vein sphalerite from different ore-forming stages of the Porgera Au-Ag mine, Papua New Guinea. Elements were measured in situ over the growth of crystals to investigate the greatly varying concentrations of cations in sphalerite and their positions in the lattice. Traverse profiles for 16 elements were obtained and aligned to transmitted light images where possible. Each sample contained an array of elements, with many displaying orders of magnitude concentration differences. Results show the simultaneous incorporation of Cu and Sn in sphalerite, as well as Cu and Ag, In and Sn, As and Sb, Fe and Mn, and Cu and Ga. The relation [4Zn2+ ↔ 2Cu+ + Sn2+ + Sn4+] is proposed to explain the 1:1 Cu–Sn correlation. Further relations can be seen, including a Ga “ceiling” or Cu “floor”, where Ga incorporation becomes dependent on Cu concentrations. Furthermore, silver was also observed to correlate with Au, Mn, Ni, Pb, and Bi. Meta-stable solid solutions between pairs such as Cu, Ag; Fe, Mn; As, Sb; and In, Sn are also suggested. Each of these pairs are neighbors on the periodic table of elements, which suggests that simple solid solution can occur, and positive correlations for all four solid solutions were found in one sample alone. While the concept of charge-specific solid solutions in sphalerite has been discussed in the literature with reference to monovalent cations, the results presented herein also indicate solid solutions of higher oxidation states, containing many cations. Furthermore, while cations in charge-specific solid solutions have been proposed to compete for lattice sites in sphalerite, simultaneous in situ coupled concentrations at Porgera suggest otherwise. Cationic substitution equations displaying decimal ratios of each element in solid solution can then provide a novel method to distinguish between solid solution concentrations in different samples. For example, displaying 1:1 ratios of Cu–Ag and Sb–As: [2Zn2+ ↔ (Cu+0.5, Ag+0.5) + (As3+0.5, Sb3+0.5)], or for a 100:1 Fe–Mn ratio: [Zn2+ ↔ (Fe2+0.99, Mn2+0.01)].

Neutron Diffraction Studies on the Structure and Conduction Mechanism in Al, Ga—DOPED Li4SiO4

1990 ◽  
Vol 210 ◽  
Author(s):  
R.I. Smith ◽  
A.R. West
Keyword(s):  
Solid Solution ◽  
Neutron Diffraction ◽  
Solid Solutions ◽  
Conduction Mechanism ◽  
One Dimensional ◽  
Linear Defects ◽  
Solution Mechanism

AbstractCrystallographic results on the Li4-3x(Al,Ga)xSiO4 solid solutions are reviewed. The six sets of sites available for Li+ ions fall into two groups. The ‘framework’ sites, which also contain the substitutional Al,Ga ions, appear to have little effect on conductivity. The ‘channel’sites contain varying amounts of Li+ ions and are responsible for the dramatic variations in conductivity with x. There is evidence for the presence of one—dimensional defects, comprising columns of ordered Li+ ions, in both the framework and channel sites. The relative numbers of these linear defects has a large bearing on the solid solution mechanism in the framework sites and their occurrence in the channel sites may be responsible for the low conductivity in stoichiometric Li4SiO4.

Synthesis of ZrO2–Y6WO12 solid solution powders by a polymerized complex method

1998 ◽  
Vol 13 (4) ◽  
pp. 939-943 ◽  
Author(s):  
Junfeng Ma ◽  
Masahiro Yoshimura ◽  
Masato Kakihana ◽  
Masatomo Yashima
Keyword(s):  
Solid Solution ◽  
Crystallite Size ◽  
Surface Area ◽  
Solid Solutions ◽  
Lattice Parameter ◽  
Cubic Phase ◽  
Complex Method ◽  
Amorphous Precursor ◽  
Fine Powders ◽  
Polymerized Complex Method

A series of solid solutions (1 − x) ZrO2 · xY0.857 W0.143 O1.714 (1/7Y6WO12) of metastable cubic phase were synthesized at 800 °C through a polymerized complex method. Lattice parameter a0 of solid solutions varies linearly with Y0.857 W0.143 O1.714 content (x). Crystallization began to occur above 400 °C from amorphous precursor to yield at 800 °C fine powders of 6–10 nm and 19–40 m2/g for crystallite size and surface area, respectively.

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