Advanced Functional Materials, Vol.17, No.13, 2198-2202, 2007
Dual-activity controlled asymmetric synthesis of superconducting lead hemispheres
A binary surfactant mixture of cetyltrimethylammonium bromide and polyvinyl pyrrolidone is used as the tailoring agent in the fabrication of lead micro/nanostructures. Electron microscopy studies indicate that the morphologies of the products can be efficiently controlled in this simple one-step synthetic procedure. Intriguingly, well-defined asymmetric functional colloids, Pb hemispheres are obtained for the first time, and a dual-activity-controlled growth process is proposed to explain their formation. The magnetization measurements show that the as prepared samples are superconducting with the same transition temperature as bulk Pb. These findings prove the unique morphology tailoring efficacy of mixed surfactants, which could be used to obtain more vairform structures or architectures in the fabrication of advanced materials.