Superconductivity near 35 K in aligned amorphous magnesium-doped BMgx nanowires

Abstract

We report the superconductivity near 35 K in magnesium-doped boron nanowires, BMgx (x≈0.1), which were synthesized via the reaction of well-aligned amorphous boron nanowires with magnesium vapor in vacuum-sealed quartz tubes. Electron microscopy and electron energy-loss spectroscopy reveal that the BMgx nanowires have an amorphous structure with magnesium content of ∼10 at. %, far less than that in crystalline MgB2, and magnesium distributes uniformly in the nanowires. Our results provide a base material not only for low-temperature nanodevice applications but also for theoretical investigations on the mechanism of its superconductivity. © 2005 American Institute of Physics.