Guoyin Shen, Vitali Prakapenka, Mark Rivers, Steve Sutton, University of Chicago
APS-GSECARS
Ninety-six percent of the Earth's core by volume is in a liquid state. Knowledge
of the behavior of liquid iron at high pressures and temperatures is geophysically
important. With the development of synchrotron facilities, direct measurements
on structures of non-crystalline materials become feasible at high pressures
and high temperatures. Information on the local structure (microscopic data)
provides a basis for understanding numerous macroscopic properties such as compressibility
and viscosity.
We report our recent results on (1) room temperature compression of amorphous
iron up to 67 GPa, and (2) the structure of liquid iron at high pressures and
high temperatures. The experiments were performed using a modified diamond anvil
cell (DAC) that allows measurements of x-ray scattering to a maximum momentum
of 86 1/nm using a monochromatic beam at a wavelength of 0.3311 Å. It
is shown that accurate structural determination can be made on amorphous materials
in a DAC to ultra high pressures.