Site preference of Fe atoms in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mtext>FeMgSiO</mml:mtext></mml:mrow><mml:mn>4</mml:mn></mml:msub></mml:mrow></mml:math>and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mtext>FeMg</mml:mtext><mml:msub><mml:mrow><mml:mrow><mml:mo>(</mml:mo><mml:mrow><mml:msub><mml:mrow><mml:mtext>SiO</mml:mtext></mml:mrow><mml:mn>3</mml:mn></mml:msub></mml:mrow><mml:mo>)</mml:m

Chatterjee, Swastika; Sengupta, Surajit; Saha‐Dasgupta, Tanusri; Chatterjee, Koustav; Mandal, Nibir

doi:10.1103/physrevb.79.115103

Cited by 24 publications

(18 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Traditionally, theoretical calculations in isotope fractionation employ a reduced partition function written in terms of phonon frequencies of the system as detailed earlier. We also employed the Boltzmann distribution method, which uses the total energy (the sum of electronic and thermal energies at a given temperature) of the system to determine the isotopic fractionation in molecules 10,45,46,49–51 and the abundance of stereoisomers 52 . For different isotopologues of the same molecule, the electronic energies are identical and do not contribute to the isotopic fractionation.…”

Section: Theoretical and Computational Methodsmentioning

confidence: 99%

Isotopic fractionation during acid digestion of calcite: A combined ab initio quantum chemical simulation and experimental study

Pramanik

Chatterjee

Fosu

et al. 2020

Rapid Comm Mass Spectrometry

Self Cite

View full text Add to dashboard Cite

Rationale:Carbonate clumped isotope analysis involves the reaction of carbonate minerals with phosphoric acid to release CO 2 for measurement in a gas-source isotope ratio mass spectrometer. Although the clumped isotope proxy is based on the temperature dependence of 13 C-18 O bonding preference in the mineral lattice, which is captured in the product CO 2 , there is limited information on the phosphoric acid reaction mechanism and the magnitude of clumped isotopic fractionation (mass 63 in CO 3 2− to mass 47 in CO 2 ) during the acid digestion. Methods:We studied the reaction mechanism for the phosphoric acid digestion of calcite using first-principles density functional theory. We identified the transition state structures for each reaction involving different isotopologues and used the corresponding vibrational frequencies in reduced partition function theory to estimate the Δ 47 acid fractionation. Experimental Δ 47 data were acquired by processing the sample CO 2 gas through the dual-inlet peripheral of a ThermoFinnigan MAT253 isotope ratio mass spectrometer. Results:We showed that the acid digestion reaction, which results in the formation of CO 2 enriched with 13 C-18 O bonds, began with the protonation of calcium carbonate in the presence of water. Our simulations yielded a relationship between the Δ 47 acid fractionation and reaction temperature as Δ 47 = −0.30175 + 0.57700 × (10 5 /T 2 ) -0.10791 × (10 5 /T 2 ) 2 , with T varying between 298.15 and 383.15 K. Conclusions:We propose a reaction mechanism that shows a higher slope (Δ 47 acid fractionation vs. 1/T 2 curve) for the phosphoric acid digestion of calcite than in previous studies. The theoretical estimates from the present and earlier studies encapsulate experimental observations from both "sealed vessel" and "common acid bath" acid digestion methods.

show abstract

Section: Theoretical and Computational Methodsmentioning

confidence: 99%

Isotopic fractionation during acid digestion of calcite: A combined ab initio quantum chemical simulation and experimental study

Pramanik

Chatterjee

Fosu

et al. 2020

Rapid Comm Mass Spectrometry

Self Cite

View full text Add to dashboard Cite

show abstract

“…Figure 18. Olivine crystal structure, yellow octahedrals represent transition metals (Mn, Fe, or Co) coordinated with 6 oxygen atoms [103].…”

Section: Transition Metal Silicatesmentioning

confidence: 99%

Cathode materials for magnesium and magnesium-ion based batteries

Huie

Bock

Takeuchi

et al. 2015

Coordination Chemistry Reviews

367

234

View full text Add to dashboard Cite

Rechargeable magnesium-ion batteries are a promising candidate technology to address future electrical energy storage needs of large scale mobile and stationary devices, due to the high environmental abundance of magnesium metal and divalent character of magnesium ion. With the recent increase in reports discussing cathode materials for magnesium-ion batteries, it is instructive to assess recent research in order to provide inspiration for future research. This review is a summary of the different chemistries and structures of the materials developed for magnesium ion cathodes. The particular strategies which may lead to future research initiatives are amplified.

show abstract

“…Rietveld refinements were performed with the software TOPAS 4.1 (Cohelo 2007). Crystal structures of all phases were retrieved from either the Crystallographic Open Database (Grazulis et al 2009) or from the Inorganic Cambridge Structural Database (Allmann et al 2007): goethite (Hazemann et al 1991); magnetite (Bragg 1915); clinochrysotile (Whittaker 1956); talc (Rayner and Brown 1973); quartz (Levien et al 1980); taramite (Oberti et al 2007); orthopyroxene (Chatterjee et al 2009). …”

Section: Sample Characterizationmentioning

confidence: 99%

Noise of collapsing minerals: Predictability of the compressional failure in goethite mines

Salje

Lampronti

Soto-Parra

et al. 2013

American Mineralogist

View full text Add to dashboard Cite

Compression experiments of goethite samples from an iron ore mine in New Caledonia revealed the collapse of the porous samples to follow a power law behavior. The porosity varies between 54 and 84%. The collapse under compression occurs in a series of individual events (avalanches). Each avalanche leads to a jerk in sample compression and an equivalent acoustic emission signal. The probability to find an acoustic emission signal with an energy within E and E + dE is p(E)dE, which has a power law distribution p(E) ∼ E -ε , and reveals avalanche criticality. The energy exponent ε varies systematically with the porosity of the sample between 1.6 and 2. The results are compared with previous measurements of porous silica (Vycor), which showed a slightly smaller exponent of 1.4.We observe fore-and after-shocks of the largest events. Significant correlations between the largest avalanches and fore-shocks were found in samples with high porosity. These correlations open the possibility for the prediction of a major collapse by acoustic detection of noise.

show abstract

Site preference of Fe atoms inFeMgSiO4andFeMg(SiO3)

Cited by 24 publications

References 25 publications

Isotopic fractionation during acid digestion of calcite: A combined ab initio quantum chemical simulation and experimental study

Isotopic fractionation during acid digestion of calcite: A combined ab initio quantum chemical simulation and experimental study

Cathode materials for magnesium and magnesium-ion based batteries

Noise of collapsing minerals: Predictability of the compressional failure in goethite mines

Contact Info

Product

Resources

About