TY  - JOUR
TI  - Ab initio simulations of iron-nickel alloys at Earth's core conditions
Y1  - 2012/09//
SN  - 0012-821X
AV  - public
N2  - We report ab initio density functional theory calculations on iron?nickel (Fe?Ni) alloys at conditions representative of the Earth's inner core. We test different concentrations of Ni, up to ?39 wt% using ab initio lattice dynamics, and investigate the thermodynamic and vibrational stability of the three candidate crystal structures (bcc, hcp and fcc). First of all, at inner core pressures, we find that pure Fe transforms from the hcp to the fcc phase at around 6000 K. Secondly, in agreement with low pressure experiments on Fe?Ni alloys, we find the fcc structure is stabilised by the incorporation of Ni under core pressures and temperatures. Our results show that the fcc structure may, therefore, be stable under core conditions depending on the temperature in the inner core and the Ni content. Lastly, we find that within the quasi-harmonic approximation, there is no stability field for Fe?Ni alloys in the bcc structure under core conditions.
ID  - discovery1367040
UR  - http://dx.doi.org/10.1016/j.epsl.2012.06.025
EP  -  130
N1  - This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
VL  - 345-34
SP  - 126 
KW  - iron
KW  -  nickel
KW  -  Earth's core
KW  -  ab initio
JF  - Earth and Planetary Science Letters
A1  - Cote, AS
A1  - Vocadlo, L
A1  - Brodholt, JP
ER  -