Physicists synthesize single-crystalline iron in the form likely found in Earth's core

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.