The Fe−Os (Iron-Osmium) system

Swartzendruber, L. J.; Sundman, Bo

doi:10.1007/bf02868091

Cited by 12 publications

(9 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1300°C) only binary relationships in the Fe-Ru-Os-Ir quaternary system (i.e. the Fe-Os, Fe-Ir, Fe-Ru, Ru-Ir, Ru-Os and Ir-Os systems) are available (Raub, 1959;Swartzendruber and Sundman, 1983a;Swartzendruber and Sundman, 1983b;Swartzendruber, 1984;Okamoto, 1992;Okamoto, 1994).…”

Section: Binary Relationships In the Fe-ru-os-ir Systemmentioning

confidence: 99%

“…The Os-rich end of the Fe-Os system is characterized by a hexagonal close packed (hcp) eOs phase that at 1300°C ranges between 40 and 100 at.% Os (Swartzendruber and Sundman, 1983a). The activity composition relationships for the eOs phase are described by Swartzendruber and Sundman (1983a) and may be calculated according to:…”

Section: Binary Relationships In the Fe-ru-os-ir Systemmentioning

confidence: 99%

See 1 more Smart Citation

New constraints on the genesis and long-term stability of Os-rich alloys in the Earth’s mantle

Fonseca

Laurenz

Mallmann

et al. 2012

Geochimica et Cosmochimica Acta

View full text Add to dashboard Cite

Section: Binary Relationships In the Fe-ru-os-ir Systemmentioning

confidence: 99%

Section: Binary Relationships In the Fe-ru-os-ir Systemmentioning

confidence: 99%

New constraints on the genesis and long-term stability of Os-rich alloys in the Earth’s mantle

Fonseca

Laurenz

Mallmann

et al. 2012

Geochimica et Cosmochimica Acta

View full text Add to dashboard Cite

“…7). Grain 02, which is unusually poor in Mo and essentially composed of Fe, Os, Ru, and Ir (Table 1) likely adopted a hcp structure due to extended hcp fields in the Fe‐Ru and Fe‐Os binary systems (Swartzendruber and Sundman 1983) and the occurrence of the ε ‐phase in the Fe‐Ir system (Massalski et al. 1986).…”

Section: Discussionmentioning

confidence: 99%

Structural clues to the origin of refractory metal alloys as condensates of the solar nebula

Harries

Berg

Langenhorst

et al. 2012

Meteorit & Planetary Scien

View full text Add to dashboard Cite

Abstract-Alloys of the refractory metals Re, Os, W, Ir, Ru, Mo, Pt, and Rh with small amounts of Fe and Ni are predicted to be one of the very first high-temperature condensates in a cooling gas of solar composition. Recently, such alloy grains were found in acid-resistant residues of the Murchison CM2 chondrite. We used focused ion beam (FIB) preparation to obtain electron-transparent sections of 15 submicrometer-sized refractory metal nuggets (RMNs) from the original Murchison residue. We studied their crystallography, microstructures, and internal compositional variations using transmission electron microscopy (TEM). Our results show that all RMNs studied have hexagonal close-packed (hcp) crystal structures despite considerable variations of their bulk compositions. Crystallographic superstructures or signs of spinodal decomposition are absent and defect microstructures are scarce. Internally, RMNs are compositionally homogeneous, with no evidence for zoning patterns or heterogeneities due to exsolution. Many RMNs show welldefined euhedral crystal shapes and all are nearly perfect single crystal. Our findings are consistent with a direct (near-) equilibrium condensation of refractory metals into a single alloy at high temperature in the solar nebula as predicted by current condensation models. We suggest that this alloy is generally hcp structured due to an extended e-phase field in the relevant multicomponent alloy system. The high degree of structural perfection and compositional homogeneity is attributed to high defect energies, high formation temperatures, slow cooling rates, small grain sizes, and rapid internal diffusion.

show abstract

“…The activity coefficient of Os at infinite dilution in liquid metal is calculated as described in Fortenfant et al (2002). Using the excess Gibbs energy of mixing for the binary Fe-Os system given in Swartzendruber and Sundman (1983) , the dependence on temperature (even though that c Fe liq;1 Os was estimated for 3000 K), pressure, silicate or sulfide melt composition has not been taken into account. Borisov and Palme (1998) estimated their metal/silicate melt partition coefficients for Os by dividing the amount of Os in the alloy by the amount of Os in the silicate glass, resulting in D met=sil Os between 1.2 · 10 6 to 1.1 · 10 7 .…”

Section: Implications For Core Formation Modelsmentioning

confidence: 99%

“…Results of the present study are in excellent agreement with previous determinations of D (3)). Conditions in the magma ocean were likely around 2500-3000 K, and an oxygen fugacity about 2 log-units below the iron-wü stite buffer (IW) corresponding to an absolute oxygen fugacity of 10 À4.2 bars at 3000 K, calculated using the l O2 ÀT equation for the Fe-FeO system from OÕNeill and Pownceby (1993), and correcting for the melting of Fe using the thermodynamic data from Swartzendruber and Sundman (1983).…”

Section: Implications For Core Formation Modelsmentioning

confidence: 99%