Category Physics

GA structure and sample/structure evolution from initial compounds to final NbN superconductors. (A) GA before and after processing, with the unit cell indicated by the black cube. (B) (Top) Chemical structures of compounds and (bottom) schematic of synthesis and processing steps with photographs of the final materials. Block terpolymers (ISO) are combined with the Nb2O5 sol-gel precursors in a common solvent. Hybrid block copolymer/Nb2O5 GA structures are generated by solvent evaporation–induced self-assembly. After calcination in air, the mesoporous Nb2O5 GAs are transformed to NbN GAs in a two-step nitriding process. Scale bars in all photographs represent 1 cm. NH3, ammonia.

Building on nearly 2 decades’ worth of research, Prof...

Scientists baked a leaf to demonstrate a battery. Credit: Image courtesy of Maryland NanoCenter

Scientists have a new recipe for batteries: Bake a leaf, add sodium. They used a carbonized oak leaf, pumped full of sodium, as a demonstration battery’s anode. Other studies have shown that melon skin, banana peels and peat moss can be used in this way, but a leaf needs less preparation. The scientists are trying to make a battery using sodium where most rechargeable batteries sold today use lithium. Sodium would hold more charge, but can’t handle as many charge-and-discharge cycles as Li can.

One of the roadblocks has been finding an anode material that is compatible with sodium, which is slightly larger than lithium...

Northwestern University researchers have developed a new hybrid polymer with removable supramolecular compartments, shown in this molecular model. Credit: Mark E. Seniw, Northwestern University

Imagine a polymer with removable parts that can deliver something to the environment and then be chemically regenerated to function again. Or a polymer that can lift weights, contracting and expanding the way muscles do. These functions require polymers with both rigid and soft nano-sized compartments with extremely different properties that are organized in specific ways...

This microscopic closeup shows a small sample of ytterbium dirhodium disilicide, one of the most-studied “heavy fermion” composites. The scale bar in the center of the screen is one millimeter wide. Credit: Marc Tippmann/Technical University of Munich

Physicists have made a surprising discovery that the arrangement of atomic nuclei spins helps bring about superconductivity in ytterbium dirhodium disilicide, one of the most-studied materials in a class of quantum critical compounds known as ‘heavy fermions.’ It provides further evidence that unconventional superconductivity arises from “quantum criticality.”

“There is already compelling evidence that unconventional superconductivity is linked in both copper-based and iron-based high-temperature superconductors to quantum fluctuations that a...