[Image above] Credit: NIST
Sheets of graphene and other materials that are virtually 2-D hold great promise for electronic, optical, and other high-tech applications. But the biggest limitation in unleashing this potential has been figuring out how to make these materials in the form of anything larger than tiny flakes. Now researchers at MIT have determined a way to make large sheets of one such material, called molybdenum telluride.
A team of University of Nebraska-Lincoln physicists has defied conventional wisdom by inducing stable ferroelectricity in a sheet of strontium titanate only a few nanometers thick. The researchers used piezoresponse force microscopy to confirm that stable and switchable polarization had occurred in ultrathin films of strontium titanate. The discovery contradicts the expected behavior of ferroelectric materials, which normally lose stable ferroelectric polarization as they are made thinner.
Researchers at Swinburne University of Technology, collaborating with Monash University, have developed an ultrathin, flat, ultra-lightweight graphene oxide optical lens with unprecedented flexibility. The researchers produced a film that is 300 times thinner than a sheet of paper by converting graphene oxide film to reduced graphene oxide through a photoreduction process. The ultrathin lens enables potential applications in on-chip nanophotonics and improves the conversion process of solar cells.
Creating futuristic, next generation materials called ‘metallic glass’ that are ultra-strong and ultra-flexible will become easier and cheaper, based on University of New South Wales Australia research that can predict for the first time which combinations of metals will best form these useful materials. In the new study, researchers describe a unique new model of the atomic structure of metallic glass, which allows scientists to predict the metal combinations that will have glass-forming ability.
Metallic glasses differ from ordinary metals in that they are amorphous, lacking an orderly, crystalline atomic arrangement. This random distribution of atoms gives metallic glasses unique mechanical properties but unpredictable internal structure. Researchers in the Caltech lab of Julia Greer, professor of materials science and mechanics in the Division of Engineering and Applied Science, have shown that metallic glasses do have an atomic-level structure—if you zoom in closely enough—although it differs from the periodic lattices that characterize crystalline metals.
Researchers at the University of Birmingham have shown how the development of coated silica nanoparticles could be used in restorative treatment of sensitive teeth and preventing the onset of tooth decay. The study shows how sub-micron silica particles can be prepared to deliver important compounds into damaged teeth through tubules in the dentine. The tiny particles can be bound to compounds ranging from calcium tooth building materials to antimicrobials that prevent infection.