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The phenomenon of low Al-Si ordering temperatures in aluminosilicate framework structures
phenomenon Al-Si ordering temperatures aluminosilicate framework structures
2012/4/5
The enthalpy ofordering ofAland Sibetween tetrahedral sites in framework structures is now known from several studies to bein the range 0.3-1.4 eVper two Al-O-Si linkages, depending on the structure a...
Bechererite, (Zn,Cu)6Zn2(OH)13[(Si,S)(O,OH)4]2, a novel mineral species from the Tonopah-Belmont mine, Arizona
Bechererite (Zn,Cu)6Zn2(OH)13[(Si,S)(O,OH)4]2 Tonopah-Belmont mine
2012/4/5
Bechererite is a new mineral found ondump material from the Tonopah-Belmont mine, Maricopa County, Arizona, U.S.A. It occurs as thin elongated crystals, commonly in hemispherical aggregates, and it is...
Coordination of Si in Na2O-SiO2-P2O5 glasses using Si K- and L-edge XANES
Coordination of Si Na2O-SiO2-P2O5 glasses Si K- and L-edge XANES
2012/4/5
Si K- and L-edge X-ray absorption near-edge structure (XANES) of SiOz-PzOs and NazO-SiOz-PzOs glasses containing PzOsabove 30mol%wereinvestigated using synchro-tron radiation. BothSiK-and L-edge spect...
Short-range disorder of Si and Ti in the tetrahedral double-chain unit of synthetic Ti-bearing potassium-richterite
Short-range disorder Si Ti double-chain unit of synthetic Ti-bearing potassium-richterite
2012/4/5
Ti-rich potassium-richterite samples weresynthesized at 900°C and 1kbar PH20and characterized by Fourier-transform infrared spectroscopy (FTIR) and Rietveld structure refinement. The infrared spectrum...
The use of Monte Carlo methods to determine the distribution of Al and Si cations in framework aluminosilicates from 29Si MAS NMR data
Monte Carlo methods distribution Al and Si cations framework aluminosilicates 29Si MAS NMR data
2012/4/5
AMonteCarlo method wasdeveloped to determine the distribution ofAland Sications from 29SiMASNMR data for framework aluminosilicates. The method wasused to an-alyze data obtained from Cs-exchanged leuc...
Infrared Vibrations of Hematite Formed From Aqueous- and Dry-Thermal Incubation of Si-Containing Ferrihydrite
Ferrihydrite Hematite Infrared spectroscopy Morphology Silicon Thermal treatment
2012/1/4
Ferrihydrite samples having Si/Fe molar ratios ranging from 0 to 1 were synthesized by the reaction of Fe2(SO4)3 and Na2SiO3 with NaOH to an equilibrium pH of 8.2. Hematite formed by incubating the fe...
Influence of Structural and Adsorbed Si on the Transformation of Synthetic Ferrihydrite
Adsorption Crystal structure Ferrihydrite Infrared spectroscopy Silicon Synthesis X-ray powder diffraction
2012/1/5
The transformation of ferrihydrite to goethite and/or hematite, as influenced by the presence of co-precipitated Si, was investigated by infrared spectroscopy (IR), X-ray powder diffraction (XRD), and...
Noncrystalline Fe-Si-Al-Oxyhydroxides
Gels • High-resolution transmission electron microscopy • Iron • Morphology • Noncrystalline oxyhydroxides
2011/11/25
Abstract: High-resolution transmission electron microscopy of noncrystalline Fe-Si-Al-oxyhydroxide gels shows a common structure of hollow packed spheres having external diameters ranging from 50 to 1...
DETECTION OF NONEQUIVALENT Si SITES IN SEPIOLITE AND PALYGORSKITE BY SOLID-STATE 29Si MAGIC ANGLE SPINNING-NUCLEAR MAGNETIC RESONANCE
Magic angle spinning-nuclear magnetic resonance Nuclear magnetic resonance Palygorskite Sepiolite Silicon sites
2011/11/16
DETECTION OF NONEQUIVALENT Si SITES IN SEPIOLITE AND PALYGORSKITE BY SOLID-STATE 29Si MAGIC ANGLE SPINNING-NUCLEAR MAGNETIC RESONANCE.
Kaolinite Synthesis: The Role of the Si/Al and (Alkali)/(H +) Ratio in Hydrothermal Systems
Kaolinite Synthesis Hydrothermal Systems Ratio
2012/2/14
The Si/Al ratio of an hydrothermal system plays an important role in kaolinite synthesis. If the atomic Si/Al ratio of a system is greater than 2·0, kaolinite will disappear at 345 ± 5°C and 2 kbars w...