HR: 17:57h
AN: CG24A-07    [Abstracts]
TI: Compressional Wave Velocities and Structure of Fe-Ni-Si and Fe-Ni-S Melts to 1650°C
AU: * Manghnani, M H
EM: murli@soest.hawaii.edu
AF: University of Hawaii, Hawaii Institute of Geophysics & Planetology, Honolulu, HI 96822, United States
AU: Fu, S S
EM: sfu@hawaii.edu
AF: University of Hawaii, Hawaii Institute of Geophysics & Planetology, Honolulu, HI 96822, United States
AU: Secco, R A
EM: secco@uwo.ca
AF: University of Western Ontario, Department of Earth sciences, London, ON N6A 5B7, Canada
AU: Newville, M
EM: newville@cars.uchicago.edu
AF: University of Chicago, Consortium on Advanced Radiation Sources, Chicago, IL 60637, United States
AB: High-precision high-temperature ultrasonic interferometric technique was used to measure VP in three molten Fe-Ni-Si alloys containing varying amounts of Fe (75-89 wt % Fe), 5 wt % Ni, and varying amounts of Si (6-20 wt %) in the temperature range 1190-1650°C and in the frequency range 9-13 MHz. The temperature dependencies of VP for all the compositions are linear, and no dispersion is observed in the temperature and frequency ranges of the experiment. However, increasing amounts of Si cause a decrease in VP and an increase in the (dVP/dT) value. The results for the Fe-Ni-Si melts are also compared with those previously obtained for Fe, Fe-Ni and Fe-Ni-S melts. Whereas in the Fe-Ni-S melts, addition of S was observed to cause anomalous elastic behavior (+dVP/dT), the behavior in Fe-Ni-Si is normal (-dVP/dT). The differences in the high-temperature elasticity are discussed in light of the structural studies of the two systems by fluorescence X-ray absorption fine structure (XAFS)1325°C.
UR: http://www.soest.hawaii.edu
DE: 3900 MINERAL PHYSICS
DE: 3909 Elasticity and anelasticity
DE: 3939 Physical thermodynamics
DE: 3954 X-ray, neutron, and electron spectroscopy and diffraction
DE: 3994 Instruments and techniques
SC: Canadian Geophysical Union [CG]
MN: 2009 Joint Assembly