Location

University of Nevada Las Vegas, Student Union Ball Room

Start Date

6-8-2008 9:00 AM

End Date

6-8-2008 12:00 PM

Description

Nuclear resonant inelastic x-ray scattering (NRIXS) of synchrotron radiation uses the energy transferred during the inelastic nuclear absorption of photons to determine phonon density of states for solid Mössbauer isotopes. This type of experiment can be conducted at ambient and high pressures with the use of a diamond anvil cell (DAC) and a rhenium gasket. Here, we are concerned with the phonon DOS of α-FePt 10% at pressures up to 30 GPa, as well as FeAl 4.3%, 6.4%, and 27.1% at ambient pressures. The iron samples used are doped in order to increase the pressure at which the alpha to epsilon phase transition for iron occurs. As the most abundant element within Earth’s core, the study of iron is fundamental in geophysics and in terms of thermodynamic modeling.

57Fe is the most common Mössbauer isotope, and its lattice dynamics have been greatly studied. The phase transition of magnetic α-Fe, body-centered cubic structure, to nonmagnetic ε-Fe, hexagonal close-packed structure, (see figure 1) occurs around 13 GPa [1]. We recently conducted experiments at the APS on beamline 16-IDD to determine how doping Fe samples with Pt and Al affects the Fe α-ε transition. As iron is the most abundant element within Earth’s core, understanding how doping changes its transition is especially important in geophysics and in terms of thermodynamic modeling.

Keywords

Aluminum; Doping; Iron isotopes; Mössbauer isotopes; Nuclear resonant inelastic x-ray scattering (NRIXS); Platinum; Radiation

Disciplines

Geophysics and Seismology | Physics

Language

English

Comments

Abstract & poster


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Aug 6th, 9:00 AM Aug 6th, 12:00 PM

Phonon density of states of iron solid solutions at ambient and high pressures using nuclear inelastic X-ray scattering (NRIXS)

University of Nevada Las Vegas, Student Union Ball Room

Nuclear resonant inelastic x-ray scattering (NRIXS) of synchrotron radiation uses the energy transferred during the inelastic nuclear absorption of photons to determine phonon density of states for solid Mössbauer isotopes. This type of experiment can be conducted at ambient and high pressures with the use of a diamond anvil cell (DAC) and a rhenium gasket. Here, we are concerned with the phonon DOS of α-FePt 10% at pressures up to 30 GPa, as well as FeAl 4.3%, 6.4%, and 27.1% at ambient pressures. The iron samples used are doped in order to increase the pressure at which the alpha to epsilon phase transition for iron occurs. As the most abundant element within Earth’s core, the study of iron is fundamental in geophysics and in terms of thermodynamic modeling.

57Fe is the most common Mössbauer isotope, and its lattice dynamics have been greatly studied. The phase transition of magnetic α-Fe, body-centered cubic structure, to nonmagnetic ε-Fe, hexagonal close-packed structure, (see figure 1) occurs around 13 GPa [1]. We recently conducted experiments at the APS on beamline 16-IDD to determine how doping Fe samples with Pt and Al affects the Fe α-ε transition. As iron is the most abundant element within Earth’s core, understanding how doping changes its transition is especially important in geophysics and in terms of thermodynamic modeling.