Search results for " spinels"

showing 2 items of 2 documents

Characterization of synthetic Fe-Mg silicate spinels in the gamma-(Mgx,Fe1-x)2SiO4 series by means of single crystal XRD (x=0,0.4,0.5)

2009

synthetic Fe-Mg silicate spinels gamma-(MgxFe1-x)2SiO4 series single crystal XRD
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Ordering kinetics in synthetic Mg(Al,Fe3+)2O4 spinels: Quantitative elucidation of the whole Al-Mg-Fe partitioning, rate constants, activation energi…

2014

A novel procedure, based on the application of the kinetics simulator Gepasi, has been successfully applied for modeling the cation ordering process in two synthetic Mg(Al2-yFe3+y)O4 spinels (y~ 0.39 and 0.54, samples F39 and F54, respectively). The kinetic profiles suggested a two-stage mechanism, with rapid inter-site exchange of Fe3+ with Mg followed by slow exchange of Al with Mg. The trial to apply the classical approaches, based on the explicit solutions of the differential equations corresponding to single-cation (Sha-Chappel model) or two-cation (Müller model) exchange reactions, proved not feasible in the whole time range, thus implying a lack of information about the exchange proc…

KineticSettore GEO/06 - MineralogiaspinelChemistryKineticsCationic polymerizationMineralogyActivation energyRate equationKinetic energyintersite cation exchangeKineticsGeophysicsReaction rate constantIntersite cation exchange spinels kinetics rate constant activation energy geothermometersactivation energyGeochemistry and PetrologyIron contentintersite cation exchange; spinels; Kinetics; activation energy; geothermometerPhysical chemistryspinelsgeothermometerTime rangeSettore CHIM/02 - Chimica Fisica
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