Calorimetric study of the stability of high pressure phases in the systems CoOSiO2 and “FeO”SiO2, and calculation of phase diagrams in MOSiO2 systems

Navrotsky, Alexandra; Pintchovski, F.; Akimoto, Syun‐iti

doi:10.1016/0031-9201(79)90001-3

Cited by 70 publications

(9 citation statements)

References 50 publications

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“…The equilibrium phase boundary determined by the present study is also compared with the boundary calculated from thermodynamic data. The boundary calculation is made by the same method as used by Akaogi et al [1984], using an enthalpy for the olivine-spinel transition of Fe2SiO, • of 2.9 q-0.9 kJ/mol at 713øC ['Navrotsky et al, 1979], together with the equilibrium transition pressure of 5.25 GPa at 1000øC determined in this study. The effect of compression and thermal expansion on the molar volumes is corrected using the bulk moduli of the olivine and spinel phase by Sumino [1979] and Sato [1977], respectively, and thermal expansivity data at 5.3 GPa which are summarized in Table 3.…”

Section: Comparison With Thermodynamic Calculationsmentioning

confidence: 99%

In situ observation of the olivine‐spinel phase transformation in Fe₂SiO₄ using synchrotron radiation

Yagi¹,

Akaogi²,

Shimomura³

et al. 1987

J. Geophys. Res.

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174

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Detailed in situ observations of the olivine‐spinel phase transformation in Fe2SiO4 were performed using a cubic anvil type of high‐pressure and high‐temperature X ray diffraction apparatus combined with synchrotron radiation. An accurate equilibrium phase boundary, density increase at the transition, and thermal expansion of spinel phase were determined as follows: Transition pressure P (GPa) = 2.75 + 2.5 × 10−3 T (°C); Δρ at 5.3 GPa and 1000°C = 9.5%; mean volume expansion between 25°C and 1000°C at 5.3 GPa = 2.0 × 10−5 K−1. Comparisons of the observed and calculated equilibrium phase boundaries indicate that when the effect of cation disorder is taken into account, the observed phase boundary becomes consistent with thermochemical data. The thermal expansion of the spinel phase observed in its stable field differs significantly from that observed at atmospheric pressure. Nonuniform formation of the diffraction peaks of the spinel phase was not observed in the present study, which indicates that the mechanism of the olivine‐spinel transition may depend on the stress state of the specimen.

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Section: Comparison With Thermodynamic Calculationsmentioning

confidence: 99%

In situ observation of the olivine‐spinel phase transformation in Fe₂SiO₄ using synchrotron radiation

Yagi¹,

Akaogi²,

Shimomura³

et al. 1987

J. Geophys. Res.

Self Cite

174

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“…5. Navrotsky et al [19,31] measured enthalpies of formation of Co 2 SiO 4 from CoO and SiO 2 (quartz) from 2PbO . B 2 O 3 solution calorimetry, reporting -21.7 kJ · mol -1 and -23.0 kJ · mol -1 at 692 8C and 713 8C respectively.…”

Section: Coo -Sio 2 Systemmentioning

confidence: 99%

“…The reason for this discrepancy is unclear. The metasilicate, CoSiO 3 , is unstable at 1 bar although it can be synthesized at high pressure[19]. Two eutectic invariants were found by Masse and Muan: (CoO + Co 2 SiO 4 + liquid) at 1407 8C, and (Co 2 SiO 4 + SiO 2 + liquid) at 1381 8C.…”

mentioning

confidence: 93%

Thermodynamic modeling of the CoO–SiO₂and CoO–FeO–Fe₂O₃–SiO₂systems

Jung

Decterov

Pelton

2007

International Journal of Materials Research

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A complete critical evaluation and thermodynamic modeling of the phase diagrams and thermodynamic properties of oxide phases in the CoO -FeO -Fe 2 O 3 -SiO 2 system at 1 bar total pressure are presented. Optimized equations for the thermodynamic properties of all phases were obtained which reproduce all available thermodynamic and phase equilibrium data within the limits of absolute experimental accuracy from 25 8C to above the liquidus temperatures at all compositions and oxygen partial pressures. The database of the model parameters can be used, along with software for Gibbs energy minimization, to calculate any type of phase diagram section. Unexplored phase diagram sections and activities of CoO, FeO and SiO 2 in this system of industrial importance are predicted from the thermodynamic models with the optimized parameters.

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“…The advantage of this type of equation is that it requires as input data only "axially determined" material properties (i.e., pressure variation of the molar volume as measured along the room temperature axis and temperature variation as measured along the room pressure axis). Navrotsky and coworkers have used a three-parameter equation of this type to predict phase equilibria in the CoOSiO2 and FeO-SiO2 systems [Navrotsky et al, 1979] Navrotsky, 1985], and the CaGeO3 system [Ross et al, 1986]. The three parameters required as input data are the room temperature, room pressure values of KT, KT', and ctp.…”

Section: Equations Based On the Assumption That Ctp Is Independent Ofmentioning

confidence: 99%

A five‐parameter temperature‐corrected Murnaghan equation for P‐V‐T surfaces

Plymate¹,

Stout²

1989

J. Geophys. Res.

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We have derived an explicit, empirical V(T,P) equation based on an exponential temperature correction of the isothermal Murnaghan equation. The equation is symmetrical with respect to the first-and second-order derivatives of volume and is consistent with the thermodynamic relationship between (•)KT/•)T)p and (•)ctp/•)P)T. The only input data required are the five room temperature, room pressure parameters: Koo, K'oo, Ctoo, Ct'oo, and (3KT/3T)oo. We have successfully tested our equation against literature pressurevolume-temperature (P-V-T) data for two materials which exhibit quite different isochore behavior: NaC1 and S iO2 (o• quartz). For NaC1 our equation predicts isochores which are very nearly straight and parallel, reflecting the fact that the product ctpK T is approximately constant for this substance. For SiO2 our equation reproduces the strong negative curvature [(•2T/•PZ)v << 0] of the experimentally determinedisochores. These results suggest that our five-parameter equation can be used to accurately predict the P-V-T behavior of a wide variety of solids, including those for which isochore curvature is pronounced.

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Calorimetric study of the stability of high pressure phases in the systems CoOSiO2 and “FeO”SiO2, and calculation of phase diagrams in MOSiO2 systems

Cited by 70 publications

References 50 publications

In situ observation of the olivine‐spinel phase transformation in Fe₂SiO₄ using synchrotron radiation

In situ observation of the olivine‐spinel phase transformation in Fe₂SiO₄ using synchrotron radiation

Thermodynamic modeling of the CoO–SiO₂and CoO–FeO–Fe₂O₃–SiO₂systems

A five‐parameter temperature‐corrected Murnaghan equation for P‐V‐T surfaces

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Calorimetric study of the stability of high pressure phases in the systems CoOSiO2 and “FeO”SiO2, and calculation of phase diagrams in MOSiO2 systems

Cited by 70 publications

References 50 publications

In situ observation of the olivine‐spinel phase transformation in Fe2SiO4 using synchrotron radiation

In situ observation of the olivine‐spinel phase transformation in Fe2SiO4 using synchrotron radiation

Thermodynamic modeling of the CoO–SiO2and CoO–FeO–Fe2O3–SiO2systems

A five‐parameter temperature‐corrected Murnaghan equation for P‐V‐T surfaces

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Product

Resources

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In situ observation of the olivine‐spinel phase transformation in Fe₂SiO₄ using synchrotron radiation

In situ observation of the olivine‐spinel phase transformation in Fe₂SiO₄ using synchrotron radiation

Thermodynamic modeling of the CoO–SiO₂and CoO–FeO–Fe₂O₃–SiO₂systems