Detecting Earth's core in a super-ionic state

Scientists from the Chinese Academy of Sciences discovered that the innermost core of the Earth is not in a normal solid state but a superionic state.

Photo: anu.edu.au

The superionic state, an intermediate state between the solid and liquid states, is made up of solid iron and liquid-like light elements, according to a research report published today in the journal Nature. the innermost core of the Earth.

Scientists have long thought that there are some light elements in the Earth's innermost core, besides iron, because the density of this core is lower than pure iron. Those light elements could be silicon, hydrogen, carbon and oxygen, according to the scientists, but the matter of their state in the Earth's innermost core is rarely studied.

The team from the Institute of Geochemistry of the Chinese Academy of Sciences and the Advanced Research Center for High Pressure Science and Technology in Beijing conducted research on a variety of alloys including iron and light elements. under conditions of high pressure and temperature that simulate conditions in the Earth's innermost core.

The researchers found that light elements such as hydrogen, oxygen, and carbon in iron alloys transition to a superionic state under Earth's innermost core conditions, as demonstrated by having a substance-like high diffusivity. liquid. This suggests that the Earth's innermost core may be in a superionic state rather than a normal solid state.

The superionic state is a special intermediate state of matter that has both solid and liquid properties. For example, in superionic water, oxygen ions form a crystal lattice as in the solid state, while hydrogen ions move around like in the liquid state.