Working with a colleague from the European Synchrotron Radiation Facility
and another from ESRF, BP220, F-38043 Grenoble Cedex, a group of physicists
and geologists from CEA DAM-DIF and Universit'e Paris-Saclay have
successfully synthesized a single-crystalline iron that resembles the iron
found in the Earth's core.
The team's study, which was published in the journal Physical Review
Letters, details their experimental method for creating pure
single-crystalline -iron and potential applications for the substance.
The majority of seismological data has been used by scientists to try to
comprehend the internal makeup of the Earth. These investigations have
persuaded scientists that the core is solid and surrounded by liquid. But
concerns still exist. For instance, research from the 1980s showed that
seismic waves move through the Earth more quickly when moving from pole to
pole than from equator to equator, but no one knew why.
According to the majority of hypotheses, the structure of the iron in the
core is probably to blame. The majority of experts in the subject concur
that these queries might be addressed with a respectable level of confidence
if the sort of iron that occurs in the core could be manufactured and
analyzed at the surface. But because of the fracture that occurs during
synthesis, doing so has proven to be difficult. The study team has
discovered a solution to these issues in this new endeavor, and in doing so,
has discovered a means to synthesis a sort of iron that may be used to
evaluate the characteristics of iron in the Earth's core.
The team's study required compressing a sample of -iron at a pressure of
7GPa. Its temperature increased to about 800 Kelvin as a result. This caused
the structure to change into crystals of -iron. More pressure forced the
-iron to transform into -structure iron, which is composed of solitary
crystals that are thought to be similar to those found in the iron in the
Earth's core.
In studies, the study team demonstrated that the directionally dependent
elasticity of their -iron behaved like the iron in the Earth's core, with
vibrations propagating more quickly down one axis of a sphere than the
other. They advise using this method to produce iron samples to test
hypotheses about the composition of the Earth's core.
