Scientists discover 2-D magnet
A top-view depiction of a single layer of chromium triiodideEfren Navarro-Moratalla/University of Washington

Scientists have discovered magnetic properties in the 2-D world of monolayers or materials that are formed by a single atomic layer.

A team of scientists led by the University of Washington and the Massachusetts Institute of Technology has proved that chromium triiodide (Crl3) has magnetic properties in its monolayer, which may open up a world of potential applications in computing and information technologies.

"What we have discovered here is an isolated 2-D material with intrinsic magnetism, and the magnetism in the system is highly robust. We envision that new information technologies may emerge based on these new 2-D magnets," said Xiaodong Xu, a UW professor of physics and materials science and engineering.

Other groups of scientists had previously shown Crl3 is ferromagnetic. But 3-D magnetic substance had not retained its magnetic properties when thinned down to a single atomic sheet. Scientists say monolayer materials can demonstrate unique properties not seen in 3-D forms.

"You simply cannot accurately predict what the electric, magnetic, physical or chemical properties of a 2-D monolayer crystal will be based on the behavior of its 3-D bulk counterpart," said UW doctoral student Bevin Huang.

To discover the magnetic properties of Crl3, the scientists use Scotch tape to shave a monolayer of Crl3 off 3-D crystal form.

"Using Scotch tape to exfoliate a monolayer from its 3-D bulk crystal is surprisingly effective. This simple, low-cost technique was first used to obtain graphene, the 2-D form of graphite, and has been used successfully since then with other materials," said UW doctoral student Genevieve Clark.

Xu and his team want to investigate the magnetic properties in 2-D magnet and heterostructures containing a CrI3 monolayer or bilayer.