| Abstract
| - A solution-phase, precursor method has been demonstrated for the large-scale synthesis of single crystallinenanowires of lead with uniform diameters in the range 50−90 nm and lengths up to several millimeters. Ina typical procedure, the nanowires were synthesized by refluxing a mixture of Pb(CH3COO)2·3H2O and poly(vinyl pyrrolidone) (PVP) in ethylene glycol under N2 for 90 min. Elemental lead was generated as a resultof thermal decomposition of the precursor salt. Electron microscopic studies indicated that a solution−liquid−solid (SLS) growth mechanism was responsible for the nucleation and growth of lead atoms into singlecrystalline nanowires. When the hot reaction solution was injected into a cold ethanol bath through a syringeneedle, bundles made of uniaxially aligned lead nanowires were formed. It was found that both compositionand morphology of the product had a strong dependence on the reaction conditions that included the molarratio between PVP and lead acetate, the reaction temperature, and the environment (nitrogen versus air). Asthe parameters were varied, nanostructures with a range of morphologies and compositions were observed asthe products. Transport measurements on individual lead nanowires (as thin as ∼50 nm in diameter) suggesta transition to the superconducting state around 7.13 K, a temperature similar to the value (7.20 K) reportedfor bulk lead.
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