News from the NNI Community - Research Advances Funded by Agencies Participating in the NNI

Scientists at Northwestern University and the U.S. Department of Energy's Argonne National Laboratory have accidentally discovered a material that is only four atoms thick and allows for studying the motion of charged particles in only two dimensions. The material is a combination of silver, potassium, and selenium in a four-layered structure similar to a wedding cake. The team measured how the ions diffused in this solid and found it to be equivalent to that of a heavily salted water electrolyte, one of the fastest known ionic conductors.

Researchers at Arizona State University have found that clusters of chromium oxide atoms can be fine-tuned to alter their electrical conductance, behaving as wire-like conductors of electricity, semiconductors, or insulators, depending on the number of oxygen atoms present. The results open the door to a new breed of electronics that may soon reach the smallest possible scale, permitting the design of tunable, molecular-sized components that could vastly increase processing and storage capacities in new devices. Such innovations are part of an ongoing change in electronics known as spintronics.

Scientists at the U.S. Department of Energy's Argonne National Laboratory have seen a new kind of wave pattern emerge in a thin film of metal oxide, known as titania, when its shape is confined. In the case of titania, this wave pattern caused electrons to interfere with each other in a unique way, which increased the oxide's conductivity, or the degree to which it conducts electricity. This work offers scientists more insight about how atoms, electrons, and other particles behave at the quantum level. Such information could aid in designing new materials that can process information and be useful in electronic applications.

Researchers from Purdue University, the National Research Council of Canada, and the University of Ottawa have used titanium nitride to achieve high-harmonic generation (HHG) in refractory metals for the first time. This achievement could pave the way to focusing the radiation down to the nanoscale for use in nanomachining, nanofabrication, and medical applications, as well as HHG enhancement for the generation of frequency combs for the next generation of nuclear clocks.

Researchers at the University of California San Diego have joined two types of quantum substances: superconducting materials based on copper oxide and nickel oxide-based insulator transition materials. The researchers used these materials to create basic "loop devices" that could be precisely controlled at the nanoscale to reflect the way the brain’s neurons and synapses are connected. Simulating the addition of more loops to the artificial brain would allow the creation of an array of networked devices that display emergent properties, as in an animal's brain.

Researchers at the University of Central Florida have created a new nanomaterial based on fullerenes that is water repellant and can stay dry even when submerged underwater. Fullerenes are bundles of 60 or 70 carbon atoms that form cage-like closed structures. These cages can stack on top of each other to form tall crystals called fullerites. By placing a drop of a gel created from fullerites on any surface, a super water-repellent state is triggered. The discovery could open the door to the development of more efficient water-repellent surfaces, fuel cells, and electronic sensors that can detect toxins. 

MIT researchers have demonstrated that when two single sheets of boron nitride are stacked parallel to each other, the material becomes ferroelectric, a state in which positive and negative charges in the material spontaneously head to different poles. They also discovered that twisting these parallel sheets at a slight angle to each other resulted in a new type of ferroelectric state. Among the potential applications of the new ultrathin ferroelectric material is its use for denser memory storage. Boron nitride is known as “white graphene” because of the similarity of its structure to graphene.

Researchers from the U.S. Department of Energy’s (DOE) Argonne National Laboratory, Brookhaven National Laboratory, Los Alamos National Laboratory, and SLAC National Accelerator Laboratory have stabilized perovskite nanocrystals to make more efficient and longer-lived light-emitting diodes (LEDs), with applications in consumer electronics, medicine, and security. The researchers fabricated the perovskite crystals within the matrix of a metal-organic framework (MOF), which keeps the nanocrystals separated, so they don’t interact and degrade. The MOF-stabilized LEDs can be fabricated to create bright red, blue, and green light, along with varying shades of each color.

A team of U.S. and Polish scientists used the Stokes-Einstein relationship to describe diffusive behavior of polymer-coated inorganic nanoparticles in biological fluids that are typically present in human joints. Understanding the diffusion of nanoparticles in biological fluids, such as synovial fluid and hyaluronic acids, is key to designing nanoparticles for biomedical applications.

Researchers at the University of Houston have developed an electrochemical device or actuator that transforms electrical energy to mechanical motion using specialized organic semiconductor nanotubes (OSNTs). These OSNTs displayed low power consumption, a large deformation, fast response, and actuation stability. Breakthroughs in OSNT-based electrochemical devices will help to usher in the next generation of soft robotics, artificial muscles, bioelectronics, and biomedical devices.