You may have heard of graphene, the ultra-thin wonder material that is a single layer of pure carbon, derived from graphene. Well, scientists at the University of Washington and the Massachusetts Institute of Technology (MIT) have just employed the same technique that is used for skimming graphene from graphite to develop the thinnest magnet ever created.
It is so thin, in fact, that it counts as the world’s first 2D magnet, with a thickness of just one atom. This counts as being functionally two-dimensional because electrons can only travel within the atomic sheet, akin to pieces moving on a chessboard. Up until now, no 3D magnetic substance has been able to retain its magnetic properties after being thinned down to a single atomic sheet.
The development demonstrates that magnetism can work in the 2D world, which could have major implications for building future quantum computers.
“In general, magnets have critical application in sensing and information technologies, such as modern hard-disk storage,” Xiaodong Xu, a University of Washington professor of Physics and of Materials Science and Engineering, told Digital Trends. “2D magnets may offer new opportunities in nanoscale spintronic devices along the same line of applications. However, since this is the first discovery of isolated monolayer magnet at the truly 2D limit, lots fundamental questions need to be addressed before figuring out the killer applications.”
The work was described in a paper published this week in the journal Nature. It details the process of creating the magnets, which are derived from a ferromagnetic material called chromium triiodide. This is stripped down into individual flakes one atom thick using a surprisingly low-fi technique: Using Scotch tape to peel off layers. Chromium triiodide has various properties that led researchers to theorize it could be used to create 2D magnets, such as the fact that it is “anisotropic,” meaning that its electrons’ spin direction run perpendicular to the plane of the crystal.
Interestingly, the magnetic signal of the 2D magnet disappeared when the flakes were two atoms thick instead of just one, although the magnetic property returned in sheets of three layers.