Extremely high pressure and temperature define the core of Earth, the deepest region of our planet. It is made up of a solid inner core and a liquid outer core. The inner core is created and expands when liquid iron solidifies at the inner core barrier. The inner core is less dense than pure iron, and it is thought that certain light elements are there.
The Chinese Academy of Sciences has discovered that Earth’s deep core may be weirder than previously assumed. New simulations reveal it exists as a superionic state of matter, halfway between a liquid and a solid, rather than as a solid.
The inner core of the Earth, according to a collaborative research team led by Prof. HE Yu of the Chinese Academy of Sciences’ Institute of Geochemistry (IGCAS), is made up of a solid iron sublattice and liquid-like light elements, which is known as a superionic condition. Under inner core conditions, the liquid-like light elements are very diffusive in iron sublattices.
These experiments have repeatedly demonstrated that the inner core can transmit a form of seismic ripple known as shear waves, indicating that it is solid. However, these waves flow through the core at a slower rate than one would anticipate from a solid iron ball, implying that it is softer.
Light elements become disorganised and disperse like a liquid in superionic iron alloys, whereas iron atoms stay ordered and vibrate around their lattice grid, producing the solid iron framework. C, H, and O diffusion coefficients in superionic iron alloys are identical to those in liquid Fe.
Seismic velocities can be affected by very diffusive light components, offering crucial clues to other mysteries in the deep core. The superionic model may explain the anisotropic structure, seismic wave attenuations, and structural changes of the inner core over the decades by examining the distribution and convection of these liquid-like materials in the inner core.