Scientists unlock the properties of new 2-D material

July 24, 2018, Institute of Physics

A new two-dimensional material has become a reality, thanks to a team of Danish and Italian scientists.

The research, led by physicists at Aarhus University, succeeded in the first experimental realisation and structural investigation of single-layer disulphide (VS2). It is published today in the journal 2-D Materials.

VS2 is one of a diverse group of compounds known as (TMDs). Many of these can assume a layered crystal structure from which atomically thin crystalline sheets can be isolated. The electronic properties of the single-atomic-layer crystals can differ in important ways from those of the layered bulk crystals.

Lead author Dr. Charlotte Sanders of Aarhus University explained the importance of the new findings: "Theoretical studies suggest that single-layer VS2 might exhibit very interesting physics, including magnetism and strong correlations. It might also host charge density wave states, as does bulk VS2. However, making VS2 is difficult and the single layer has not been successfully made before now.

"In fact, magnetism in single-layer has only recently been observed, and is still quite rare. So, the possibility that this material might be magnetic is exciting."

To make the single layer of VS2, the researchers evaporated vanadium onto a clean gold surface at room temperature. They then heated the sample in the presence of sulphur-containing molecules that react with the vanadium to produce the VS2. The team measured the properties of the samples using low-energy electron diffraction, scanning tunnelling microscopy, and X-ray photoelectron spectroscopy.

Significantly, the team also discovered a new and unpredicted vanadium sulphide compound. Most 2-D materials can, in theory (although not necessarily in practice), be derived from bulk layered crystals. However, there is no 3-D material that has similar stoichiometry and to those of the new compound, which is formed when single-layer VS2 is depleted of sulphur by heating.

In consideration of the likely magnetic properties of related vanadium , the new material might be another candidate for two-dimensional magnetism.

"The new material's electronic structure, along with possible charge density wave phases and magnetic ordering, remain to be explored, and an interesting open question is how its properties differ from those of stoichiometric single-layer VS2," said Dr. Sanders.

Explore further: Mixed halide chemistry can be used to control magnetism in ultrathin magnetic devices

More information: "Novel single-layer vanadium sulphide phases" Arnold et al 2018 2D Mater. 8 045009, DOI: 10.1088/2053-1583/aad0c8

Related Stories

NbSe2, a true 2-D superconductor

November 6, 2015

An international team led by Miguel M. Ugeda and Michael F. Crommie has demonstrated the coexistence of superconductivity and charge density wave order in a single layer of NbSe2, a model transition metal dichalcogenide metal. ...

The shape of things to come for quantum materials?

March 1, 2018

For the first time, researchers isolated and characterized atomically thin 2-D crystals of pentagons bonded together in palladium diselenide (PdSe2). The research confirmed predictions that the puckered structure would be ...

Creating a 2-D platinum magnet

April 6, 2018

University of Groningen physicists have induced magnetism in platinum with an electric field created by a paramagnetic ionic liquid. As only the surface of the platinum is affected, this creates a switchable 2-D ferromagnet. ...

Recommended for you

How to mass produce cell-sized robots

October 23, 2018

Tiny robots no bigger than a cell could be mass-produced using a new method developed by researchers at MIT. The microscopic devices, which the team calls "syncells" (short for synthetic cells), might eventually be used to ...

Nanosized ferroelectrics become a reality

October 22, 2018

Using ferroelectricity instead of magnetism in computer memory saves energy. If ferroelectric bits were nanosized, this would also save space. But conventional wisdom dictates that ferroelectric properties disappear when ...

Taking steps toward a wearable artificial kidney

October 17, 2018

There just aren't enough kidney transplants available for the millions of people with renal failure. Aside from a transplant, the only alternative for patients is to undergo regular dialysis sessions to clear harmful cellular ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

24volts
not rated yet Jul 25, 2018
I think they should put the exotic stuff aside for a while and try making single-atom layers of common materials like iron, tin, lead, aluminum, etc to find out what those might be capable of.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.