Basic science

Researchers from Columbia University and the National Institute for Materials Science in Tsukuba, Japan, have used commercially available tabletop lasers to create tiny, atomically sharp nanostructures, or nanopatterns, in samples of a layered two-dimensional (2D) material. Rather than damaging the underlying atomic structure, the lasers broke the crystal lattice cleanly apart. According to Cecilia Chen, a scientist who led this study, the effect was visible under the microscope and looked like unzipping a zipper.

Scientists from the Massachusetts Institute of Technology, the University of Texas at Dallas, and  the National Institute for Materials Science in Tsukuba, Japan, have created a “five-lane superhighway” for electrons in a material called rhombohedral graphene, which is composed of five layers of graphene stacked in a specific overlapping order. In October 2023, the scientists had shown that rhombohedral graphene could allow the unimpeded movement of electrons around the edge of the material but not through the middle.

Researchers from the University of Illinois Urbana-Champaign and the University of Duisburg-Essen in Germany have shown that when graphene is irradiated with ions, or electrically charged atoms, the electrons that are ejected give information about the graphene’s electronic behavior. “Irradiating materials and observing the change in properties to deduce what’s going on inside the material is a well-established technique, but now, we are taking first steps towards using ions instead of laser light for that purpose,” said André Schleife, one of the scientists involved in this study.

A team of electrical engineering researchers from Penn State and the University of Nebraska-Lincoln has created an ultrathin optical element that can control the direction of polarized electromagnetic light waves. The optical element, akin to a glass slide, uses a forest of tiny, antenna-like nanorods that together create a metamaterial – a material engineered to have specific properties not typically found in nature.

Researchers from North Carolina State University and Texas A&M University have created materials that are stiff and can insulate against heat. This combination of properties is unusual and holds promise for the development of thermal insulation coatings for electronic devices. The researchers were working with a subset of a class of materials called two-dimensional hybrid organic-inorganic perovskites (2D HOIP). The researchers found at least three distinct 2D HOIP materials that became less thermally conductive as their stiffness increased.

Engineers from Columbia University, the National Institute of Standards and Technology, the University of Montreal in Canada, and the National Institute for Materials Science in Tsukuba, Japan, have shown that an oxygen-free chemical vapor deposition (CVD) method can create high-quality graphene samples at scale. Their work directly demonstrates how trace oxygen affects the growth rate of graphene and, for the first time, identifies the link between oxygen and graphene quality.

Imaging the hot turbulence of aircraft propulsion systems may now be possible with sturdy sheets of composite materials that twist light beams, according to researchers from the University of Michigan, the Air Force Research Laboratory, ARCTOS Technology Solutions (Beavercreek, OH), the Brazilian Center for Research in Energy and Materials in Campinas, Brazil, and the Federal University of São Carlos in Brazil. The key is arranging nanomaterials that don't twist light on their own onto layers that turn light waves into either left- or right-handed spirals, known as circular polarizations.

Researchers from the U.S. Department of Energy's Brookhaven National Laboratory and Oak Ridge National Laboratory; Stony Brook University; Chungnam National University in Daejeon, South Korea; and Mitsubishi Chemical Corporation in Yokohama, Japan, have uncovered new details of the reversible assembly and disassembly of a platinum catalyst. The researchers revealed how single platinum atoms on a cerium oxide support aggregate under reaction conditions to form active catalytic nanoparticles and then, surprisingly, disaggregate once the reaction is stopped.

Researchers from Purdue University and ShanghaiTech University in China have developed a patent-pending method to synthesize high-quality, layered perovskite nanowires with large aspect ratios and tunable organic-inorganic chemical compositions. Layered metal halide perovskites, commonly called 2D perovskites, grow into large, thin sheets, but growth of one-dimensional forms of the materials is limited. The new method uses organic templating molecules that break the in-plane symmetry of layered perovskites and induce one-dimensional growth through secondary bonding interactions.

Researchers from North Carolina State University; Stanford University; the U.S. Department of Energy’s Lawrence Berkeley National Laboratory and SLAC National Accelerator Laboratory; and the University of Geneva have, for the first time, demonstrated that a specific class of oxide membranes can confine, or "squeeze," infrared light. The thin-film membranes (which are 100-nanometer-thick) confine infrared light far better than bulk crystals, which are the established technology for infrared light confinement.