HR: 0830h
AN: V51A-11    [Abstracts]
TI: Density Measurement of Liquid FeS Under High Pressure and High Temperature
AU: * Yu, T
EM: tony.yu@sunysb.edu
AF: SUNY Stony Brook, Department of Geosciences, Stony Brook, NY 11794-2100 United States
AU: Young, C
EM: ceyoung@gmail.com
AF: SUNY Stony Brook, Department of Geosciences, Stony Brook, NY 11794-2100 United States
AU: Chen, J
EM: jiuhua.chen@sunysb.edu
AF: SUNY Stony Brook, Department of Geosciences, Stony Brook, NY 11794-2100 United States
AU: Baldwin, K
EM: kenneth.baldwin@sunysb.edu
AF: SUNY Stony Brook, Department of Geosciences, Stony Brook, NY 11794-2100 United States
AB: Sulfur is considered one of the possible light elements in the core which might be responsible for the density deficit. We studied the liquid state of sulfur in iron due to sulfur­Ęs lack of amount in the mantle; easiness to alloy with iron; and the predicted 5% ~ 10% amount of this light element in the core (Ahrens, 1979; Sherman, 1997). Restricted by the modern development of the multianvil high pressure experimental equipments, the experiments are limited at a lower pressure range (<30GPa) comparing with the outer core pressure condition. Therefore, extrapolation of data derived at low pressure range to the condition of the outer core (130-330GPa) has to be applied and may produce results which are way far from the true numbers. However, at the point while the techniques are limited, studying the physical properties of the molten FeS at relatively low pressure still provides us a better picture of the physical behaviors of the liquid outer core comparing with data derived from solid state FeS experiments. The lack of melt density data at low pressure provides another motivation for us to study the physical properties of melt. The radiography (shadowgraphy) system on Beam Line X17B2, NSLS at the Brookhaven National Laboratory is an add-on system attached to the in situ x-ray beam line setup. It includes a YAG fluorescent screen, an optical mirror, focusing-magnification lenses, and a CCD camera and/or a video camera. Before the melting temperature, the radiograph system yields a maximum 1% difference in density comparing with the data collected by the traditional x-ray diffraction method. We have successfully examined liquid FeS samples by applying this technique at the NSLS. With a sapphire (Al2O3) sphere surrounded by FeS powder. The image of the sphere was clearly shown due to the absorption coefficient difference between these two materials. The density fitting method developed by our group has produced convincing data. The preliminary results of the density measurements of molten FeS show that the derived liquid density variation for the same sample remains under 1%. This study has collected in situ high pressure and high temperature x-ray diffraction data of the FeS sample up to 4GPa and 1400°C. Combined with the derived density data, the equation of state of the liquid FeS can be constructed.
DE: 3919 Equations of state
DE: 3954 X ray, neutron, and electron spectroscopy and diffraction
DE: 3994 Instruments and techniques
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2005 Joint Assembly