Improved understanding of groundbreaking liquid-metal 2-D technique

May 2, 2018, ARC Centres of Excellence
Improved understanding of groundbreaking liquid-metal 2-D technique
Credit: ARC Centres of Excellence

Last year, FLEET researchers at RMIT developed a ground-breaking new method of depositing atomically-thin (two-dimensional) crystals using molten metals, described as a 'once-in-a-decade' advance.

Earlier this year, the same research team expanded the new method from controlled to , and has properly characterised the for key tin oxides, which should allow improved control of target growth.

The technique developed at RMIT last year introduced (gallium-based) as a successful reaction environment for the synthesis of desirable, atomically-thin oxides that were unattainable using prior methods. It's a process so cheap and simple that it could be done on a kitchen stove by a non-scientist.

While the initial study used costly, specially-designed alloys and an often tightly-controlled environment, this latest research has confirmed that high-quality 2-D materials can be formed in ambient conditions using cheaper liquid tin, simplifying future research and applications.

Researchers also characterised the growth mechanism for the first time, creating a 'road map' of crystal formation and growth. Such growth proved surprisingly complex, with small 'islands' of tin-oxides (SnOx) forming on larger, perfect 2-D tin monoxide (SnO) monolayers, before thickening and taking on more oxygen to become tin dioxide (SnO2).

Transmission electron microscopy (TEM) images of (a) fresh, (b) yellow, (c) pink and (d) grey tin oxides. Credit: ARC Centres of Excellence

Future applications

This simple, repeatable method of growing 2-D tin-oxide crystals can be expanded to other low-melting point liquid metals and their alloys.

Having properly characterised growth mechanisms, researchers believe it should be possible to control the rate of surface oxide formation by careful control of the atmospheric oxygen content, and hence control the number and thickness of oxide layers and resulting stoichiometry.

Tin oxides are of particular interest as 2-D materials. Electronically, they can be both p-type (SnO) or n-type (SnO2) semiconductors, which is of great interest to field effect transistor (FET) designers.

Evolution of 2-D tin oxides on the surface of molten tin was published in Chemical Communications in January 2018.

The study was conducted using the facilities and expertise of the Australian Microscopy and Microanalysis Research Facility at the RMIT Microscopy & Microanalysis Facility, and the Micro Nano Research Facility at RMIT. Co-author Torben Daeneke received support from the RMIT Vice Chancellor's research fellow scheme.

Explore further: Liquid metal discovery ushers in new wave of chemistry and electronics

More information: P. Atkin et al. Evolution of 2D tin oxides on the surface of molten tin, Chemical Communications (2018). DOI: 10.1039/C7CC09040D

Related Stories

New catalytic effect discovered for producing gallium oxide

November 30, 2017

Semiconducting oxides are a new class of materials that are currently enjoying great attention in the field of semiconductor technology. Gallium oxide is the archetypal example for its ability to handle extremely high voltages ...

Recommended for you

Research team uncovers lost images from the 19th century

June 22, 2018

Art curators will be able to recover images on daguerreotypes, the earliest form of photography that used silver plates, after a team of scientists led by Western University learned how to use light to see through degradation ...

Detecting metabolites at close range

June 22, 2018

A novel concept for a biosensor of the metabolite lactate combines an electron transporting polymer with lactate oxidase, which is the enzyme that specifically catalyzes the oxidation of lactate. Lactate is associated with ...

CryoEM study captures opioid signaling in the act

June 22, 2018

Opioid drugs like morphine and fentanyl are a mainstay of modern pain medicine. But they also cause constipation, are highly addictive, and can lead to fatal respiratory failure if taken at too high a dose. Scientists have ...

Researchers achieve unprecedented control of polymer grids

June 21, 2018

Synthetic polymers are ubiquitous—nylon, polyester, Teflon and epoxy, to name just a few—and these polymers are all long, linear structures that tangle into imprecise structures. Chemists have long dreamed of making polymers ...

Template to create superatoms could make for better batteries

June 21, 2018

Virginia Commonwealth University researchers have discovered a novel strategy for creating superatoms—combinations of atoms that can mimic the properties of more than one group of elements of the periodic table. These superatoms ...


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.