In-situ X-ray diffraction measurements of the [gamma-epsilon] transition boundary of iron in an internally-heated diamond anvil cell
The phase transition boundary between the {gamma} (face-centered cubic structure) and {epsilon} (hexagonal close-packed structure) iron phases was determined up to 69 GPa by using a newly developed internally-heated diamond anvil cell, combined with in-situ synchrotron X-ray diffraction measurements. The improved experimental configuration provides stable heating with reliable temperature and pressure determination and phase identification. A simultaneous laser- and internal-heating system was also used to produce further higher temperature at higher pressures. The sample pressure at any given temperature was calculated using an established thermal equation of state for {epsilon} iron. The {gamma}-{epsilon} transition boundary was bracketed with the normal and reversal directions and it is linear from 21 to 69 GPa with a dP/dT slope of 0.0394 GPa/K. There is no evidence for the existence of additional iron solid phase other than the {gamma} and {epsilon} phases over the P-T range of this study. We inferred that the {gamma}-{epsilon}-liquid triple point of iron should occur at 88 GPa and 2800 K.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 1005595
- Journal Information:
- Earth Planet. Sci. Lett., Vol. 282, Issue (1-4) ; 05, 2009; ISSN 0012-821X
- Country of Publication:
- United States
- Language:
- ENGLISH
Similar Records
High pressure–temperature phase diagram of 1,1-diamino-2,2-dinitroethylene (FOX-7)
Time-Resolved Synchrotron X-ray Diffraction on Pulse Laser Heated Iron in Diamond Anvil Cell