High-pressure polymorphism of Fe[subscript 2]P and its implications for meteorites and Earth's core
- UNLV
Minerals with composition (Fe,Ni){sub 2}P, are rare, though important accessory phases in iron and chondritic meteorites. The occurrence of these minerals in meteorites is believed to originate either from the equilibrium condensation of protoplanetary materials in solar nebulae or from the later accretion and condensation processes in the cores of parent bodies. Fe-Ni phosphides are considered a possible candidate for a minor phase present in the Earth's core, and at least partially responsible for the observed density deficit with respect to pure iron. We report results of high-pressure high-temperature X-ray diffraction experiments with synthetic barringerite (Fe{sub 2}P) up to 40 GPa and 1400 K. A new phase transition to the Co{sub 2}Si-type structure has been found at 8.0 GPa, upon heating. The high-pressure phase can be metastably quenched to ambient conditions at room temperature, and then, if heated again, transforms back to barringerite, providing an important constraint on the thermodynamic history of meteorite.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 1006601
- Journal Information:
- Geophys. Res. Lett., Vol. 35, Issue 03, 2008; ISSN 0094-8276
- Country of Publication:
- United States
- Language:
- ENGLISH
Similar Records
Formation, cooling history and age of impact events on the IIE iron parent body: Evidence from the Miles meteorite
Nickel-rich, volatile depleted iron meteorites: Relationships and formation processes