researchers at the royal melbourne institute of technology (rmit university) in australia have created two-dimensional materials that are only a few atoms thick by dissolving metals in liquid metals to create oxide layers that can be easily peeled away.
this image of a liquid metal "slug" and its clear atom-thick "trail" shows the breakthrough in action. (rmit university)
according to a report from the institute, these 2-d materials are not found in nature and have the potential to enhance data storage and make faster electronics.
“once extracted, these oxide layers can be used as transistor components in modern electronics,” the article continued. “the thinner the oxide layer, the faster the electronics are. thinner oxide layers also mean the electronics need less power. among other things, oxide layers are used to make the touch screens on smart phones.”
researchers used non-toxic alloys of gallium as a reaction medium covering the surface of the liquid metal with thin oxide layers of the added metal rather than naturally occurring gallium oxide. the layers are removed by touching the liquid metal with a smooth surface.
larger amounts of the thin layers can be produced by injecting air into the liquid metal, according to a researcher.
the article added, “it’s a process so cheap and simple that it could be done on a kitchen stove by a non-scientist.” the researchers predict that this technology could be used with one-third of the periodic table and that many of the thin oxides are semiconducting or dielectric materials.
the research was recently published in science. the abstract stated:
“two-dimensional (2d) oxides have a wide variety of applications in electronics and other technologies. however, many oxides are not easy to synthesize as 2d materials through conventional methods. we used nontoxic eutectic gallium-based alloys as a reaction solvent and co-alloyed desired metals into the melt.
“on the basis of thermodynamic considerations, we predicted the composition of the self-limiting interfacial oxide. we isolated the surface oxide as a 2d layer, either on substrates or in suspension. this enabled us to produce extremely thin subnanometer layers of hfo2, al2o3, and gd2o3.
“the liquid metal–based reaction route can be used to create 2d materials that were previously inaccessible with preexisting methods. the work introduces room-temperature liquid metals as a reaction environment for the synthesis of oxide nanomaterials with low dimensionality.”