Scientists have replicated the process of how iron behaves deep within the Earth, revealing its mysteries. Check out the revealing photos!

Iron is one of the primary elements found in the Earth's inner core, characterized by extremely high temperatures and pressures. Understanding how iron behaves under these extreme conditions may enhance our current knowledge of the Earth's interior structure and its geodynamics, as reported by PHYS.org.

In a recent study, an international team from the European Synchrotron Radiation Facility in Grenoble, the Paris Polytechnic Institute, and other institutions around the world investigated the melting temperature and phase stability of shock-compressed iron at high temperatures and pressures using ultrafast X-ray absorption spectroscopy. Their findings shed light on the melting curve and structural phase of iron under extreme conditions similar to those found in the Earth's interior.

According to the lead author of the study, their aim was to examine the microscopic behavior of iron under extreme pressure and temperature conditions, reaching ranges of several megabars and thousands of degrees Kelvin, utilizing ultrafast synchrotron X-ray absorption spectroscopy. The authors also believe that their work is crucial for understanding the properties of the Earth's core, which is primarily composed of iron with a small amount of other elements.

Since iron forms the basis of the Earth's core, its properties establish an upper limit on the melting temperature at the boundary separating the planet's inner and outer cores. Determining this temperature, scientists believe, could aid in the study of geodynamics and provide insights into the process by which the Earth's core crystallizes, forming the inner core.

The team conducted an experiment using high-power lasers with energy exceeding 40 J and an energy-dispersive beam ID24-ED optimized for ultrafast (≈100 ps) X-ray absorption spectroscopy.

According to Balugani, the powerful laser is focused on a multilayer target, removing the first layer to create hot plasma. This plasma expands and generates a shock wave that travels at supersonic speed through the iron sample. The shock wave creates extreme pressure and temperature conditions in the iron. Simultaneously, X-rays are synchronized to capture the XAS spectrum of iron at the moment the shock wave exits the sample, corresponding to peak pressure and temperature in the iron.

As a result, the researchers obtained detailed information about the structural phase of iron under extremely high pressures and temperatures. The team also identified the structural changes the element undergoes under conditions reflecting those found in the Earth's core.

Balugani stated that they and the team also established that the phase of pure iron at 240 GPa and 5345 K, just before melting, is hexagonally close-packed (HCP), rather than the body-centered cubic (BCC) structure predicted by many theoretical studies.

The authors of the study note that their findings have significant implications for future research into Earth's geodynamics. The measurements collected by the researchers may ultimately advance our understanding of the internal structure of our planet and its thermal history.

The researchers' results set new constraints on the melting curve of iron under extreme conditions, disproving some earlier theories.