From childhood, we are taught that the world exists in three physical dimensions. It’s true, for the most part, but something quite fascinating is missing: the strange two-dimensional world of nanoscale materials, such as graphene “wonderful material.”
Graphene and its designed monolayer counterparts actually exist in three dimensions, though barely sitting on the sidelines, atomically speaking. This is because these so-called 2D materials are only one atom thick and embody an incredible structural thinness that gives them all sorts of strange powers.
We see it in the formidable strength of graphene and in the way we deal with superconductivity.
Things get even weirder when graphene becomes friends: it stacks sheets of this two-dimensional material into a three-layer, three-atom-tall sandwich and reveals a rare form of magnetism.
Now, in a new study led by physicists at Cambridge University, scientists have achieved the same type of magnetic feat with a different two-dimensional material called phosphorus trisulfide (FePS).3).
(University of Cambridge)
At the top: illustration of the magnetic structure of iron-phosphorus trisulfide (FePS3), a two-dimensional material that undergoes a transition from an insulator to a metal when compressed.
FePS3 it is not the same as graphene, which is made up of a single layer of carbon atoms, but is often called ‘magnetic graphene’, due to its mysterious capabilities in ultra-thin layered dimensions.
In a previous study by some of the same researchers, the team found that when they crushed layers of FePS3 were subjected to high levels of pressure, the material went from being an insulator, preventing the flow of electrons, to a metallic state where it became a conductor.
But researchers still did not fully understand what underlies the magnetic behavior of this ‘magnetic graphene’ under pressure, as it was expected that the3 it would cease to be magnetic when it enters a metallic state.
“The missing piece has still been kept, the magnetism,” says quantum physicist Matthew Coak.
“Without experimental techniques capable of probing the signatures of the magnetism of this material at such high pressures, our international team had to develop and test our own new techniques to make it possible.”
According to new research, FePS3 it retains its magnetism under extremely high pressure due to a newly discovered magnetism that still exists during the metal phase.
“To our surprise, we found that magnetism survives and, in a way, strengthens itself,” explains Siddharth Saxena, senior researcher and physicist, leader of the group at the Cavendish Laboratory in Cambridge.
“This is unexpected, as electrons circulating freely in a newly conductive material can no longer be blocked in their parent iron atoms, generating magnetic moments in them, unless the conduction comes from an unexpected source.”
Although we do not yet have all the answers to what happens here, during compression, the “rotation” of the electrons in the material appears to be a source of magnetism, and the phenomenon can be adjusted as a function of FePS pressure.3 is subject to.
Although the results contradict previous observations about how this material should behave, the surprises found here suggest that we could further modify magnetic graphene and its condition, even by finding materials that support superconductivity due to these exotic forms of magnetism. fully understand.
“We don’t know exactly what’s going on at the quantum level, but at the same time we can manipulate it,” Saxena says.
“It’s like those famous ‘unknown unknowns’: we’ve opened a new door to the properties of quantum information, but we still don’t know what those properties may be.”
The findings are reported in Physical check X.