Dissertation/Thesis Abstract

Melting and phase relations in iron-silicon alloys with applications to the Earth's core
by Miller, Noah Andrew, M.S., University of Maryland, College Park, 2009, 87; 1469462
Abstract (Summary)

Experiments were performed on iron-silicon alloys to determine their suitability as analog compositions for the Earth’s core. Starting compositions with 9 wt.% silicon and 16 wt.% silicon were compressed in diamond anvil cells and laser-heated. The melting temperatures of the alloys were measured up to 52 GPa using a recently developed optical system. Both curves show a melting point depression from pure iron but intersect at ∼50 GPa.

The two starting compositions were also studied up to 90 GPa and over 3500 K in synchrotron x-ray diffraction experiments, and phase diagrams were constructed for both compositions that show significant deviation from the pure iron phase diagram. Based on this synchrotron data, a model was produced which predicts the core to contain 8.6 to 11.1 wt.% silicon for a core-mantle boundary temperature of 4000 K.

Indexing (document details)
Advisor: Campbell, Andrew
Commitee: Hier-Majumder, Saswata, McDonough, William
School: University of Maryland, College Park
Department: Geology
School Location: United States -- Maryland
Source: MAI 48/01M, Masters Abstracts International
Subjects: Geology, Geophysics
Keywords: Core, Earth, Iron-silicon alloys, Pressure
Publication Number: 1469462
ISBN: 978-1-109-38341-6
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