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In a significant advancement for materials science, researchers have successfully created niobium sulfide metallic nanotubes with stable, predictable properties for the first time. An international team achieved the long-sought feat using an unexpected ingredient—common table salt. According to researchers, the discovery could pave the way for faster electronics, efficient superconducting wires, and future quantum technologies. “A long-sought goal in nanomaterial research, the development of metallic nanotubes with stable properties could lead to faster electronics and more efficient electricity transport, along with enabling potential advances in quantum computing,” according to a statement by researchers. Atomic tube innovation Nanotubes are ultra-small cylindrical structures, so tiny that thousands could fit across the width of a human hair. Formed by rolling up sheets of atoms, these hollow tubes exhibit unique behaviors distinct from bulk materials due to their nanoscale dimensions. They can be stronger than steel yet lighter than plastic, conduct heat efficiently, and carry electricity with minimal resistance. In some cases, they even display remarkable quantum effects. These extraordinary properties make nanotubes highly promising for next-generation technologies in electronics, energy, and quantum research. According to researchers at Penn State’s Materials Research Institute, the characteristics of nanotubes can be precisely tuned by selecting specific atomic compositions. This tunability has driven strong interest in creating niobium disulfide nanotubes, a true metallic form with potential to advance high-speed electronics and superconductivity. Until recently, scientists could consistently produce nanotubes from carbon—capable of acting as semiconductors or semimetals—and from boron nitride, an insulator. However, creating stable metallic nanotubes had remained an unsolved challenge due to the complex behavior of metals at the atomic scale. “What we have now are metallic shells that can, in principle, show phenomena like superconductivity and magnetism, which are impossible in insulating or semiconducting versions. Previous semimetal carbon nanotubes did not show superconductivity or ferromagnetism because of low density of electrons,” said Slava V. Rotkin, professor at Penn State’s Materials Research Institute, in a statement. Next-gen metallic tubes The research team successfully transformed niobium disulfide—a metal known in its bulk form for exhibiting superconductivity—into nanotubes just billionths of a meter wide. Using a template made from carbon and boron nitride nanotubes, they successfully formed a rolled tubular structure from the material, a significant achievement since such materials typically prefer to form flat sheets. The breakthrough came when the researchers introduced a minute amount of ordinary salt at a critical stage in the process, which triggered the metal to wrap around the template instead of spreading out, enabling the formation of stable nanotube shells. Unexpectedly, the resulting nanotubes predominantly formed as double-layered structures, resembling pairs of nested cylinders. This configuration appeared to be energetically favorable, with electrons moving between the layers and stabilizing the structure much like an atomic-scale capacitor. Computational modeling supported this mechanism, revealing that the interaction between layers was key to maintaining the nanotubes’ integrity. The tubular shape of the niobium disulfide nanotubes also addresses a long-standing challenge in nanoscale fabrication. Unlike nanowires carved from flat materials, which often have rough edges that degrade performance, the rolled tubes have smooth, continuous surfaces with predictable properties. According to researchers, this structural precision could make metallic nanotubes ideal for next-generation electronic, superconducting, and quantum devices requiring atomic-level reliability. The details of the team’s research were published in the journal ACS Nano.
