Scientists think that the iron in the inner core of the Earth is in a strange "super-ionic" state

The paper's conclusions provide a good model for understanding this pure, softer and less dense iron, but they don't answer another question about the inner core: Why does it look uneven all the time?

A new study has found that the inner core of the Earth is not an ordinary solid substance, but rather consists of a solid iron lattice and light elements of a liquid-like nature, according to a report by Science Alert.

The study found that the iron in the inner core of the Earth can be in a strange "super-ionic" state with hydrogen, oxygen and carbon, which makes it different from a liquid or solid matter.

The conclusions of this paper provide a good model for this pure iron, which is softer and less dense, according to the study published in the journal Nature on February 9, by a joint scientific team of scientists from the Institute of Geochemistry of the Chinese) of the Chinese Academy of Sciences (IGCAS) and the Center for High Pressure Science & Technology Advanced Research (HPSTAR) in China.

What happens in the ground?

"Earth's core, the deepest part of our planet, is characterized by very high pressure and temperature, and consists of a liquid outer core and an inner core that grows due to the solidification of liquid iron at the inner core boundaries, and some light elements are believed to be present in it as well," says a press release from the Chinese Academy of Sciences.

The information states that the inner core of the Earth is a layer of spherical shape with a radius of 1220 km. According to the information, some physicists believe that this core is a plasma with the properties of matter.

According to Science Alert, previous studies in the thirties of the last century found evidence indicating that the inner core of the Earth could be solid, and they believed that it consisted of crystalline iron.

Because the Earth's exploration drilling cannot reach further than 6,317 kilometers toward the center of the Earth, scientists use Earth's natural drilling caused by earthquakes to understand the composition of our planet. Through seismic wave data, studies have found that the Earth's inner core is soft, which means it cannot just be solid iron or an iron ingot. Some scientists believe that there can be a second inner core, while others believe that there can be some light elements as an alloy.

Super ionic case

In the new study, the scientists concluded that the inner core is not solid at all, and instead forms a "super-ionic state", a mixture of hydrogen, oxygen and carbon. Scientists have studied this state in which this mixture of elements exists, and came to suggest that the "solid" state of the nucleus may really be a super-ionized state.

"We found that hydrogen, oxygen and carbon in hexagonal packed iron transform into a super-ionic state under internal basic conditions, and that it exhibits high diffusion coefficients as a liquid," say the researchers. The Science Alert report notes that the "super-ionic state" described in the recent study is another state of matter, along with solid, liquid, and gas, but with distinct differences.

In super-ionic water finally made in the lab, at high temperatures and pressures, every molecule of water disintegrated, leaving oxygen ions to form a solid, while hydrogen ions floated around like a liquid.

Check the ionic state

Using high-pressure and high-temperature computer simulations, the researchers found that some Fe-H, Fe-C and Fe-O iron alloys in the inner core were transformed into a super-ionic state under internal conditions.

In super-ionic iron alloys, light elements become disordered and disperse like liquid, while iron atoms remain arranged and vibrate around their lattice, forming a solid iron framework in super-ionized alloys that are the same as those found in liquid iron.

The researchers calculated the transmission velocities of seismic waves in superionic iron alloys, and found a significant decrease in the shear wave velocity. They also found that highly diffuse light elements influence seismic velocities, providing important clues to understanding other mysteries in the inner core.

The researchers say that "the hardening of iron at the inner core boundaries does not change the movement of these light elements, and the convection of light elements continues in the inner core, which is completely abnormal."

It is unlikely that this work will be the last word on the subject, as the paper's conclusions provide a good model for understanding this finer, less dense, pure iron, but they do not answer another question about the inner core: Why does it seem uneven all the time? “So we just have to keep digging,” the researchers stress.