Preparation of Carbon Nanotube Encapsulated Copper Nanowires and Their Use as a Reinforcement for Y−Ba−Cu−O Superconductors

Copper nanowires with multiwall carbon nanotubes (MWNTs) encapsulated inside were prepared via surface modification of MWNTs followed by chemical deposition of copper on surfaces. These MWNTs-encapsulated copper nanowires were investigated as a reinforcement to improve the mechanical strength of the Y−Ba−Cu−O superconductor. TEM and SEM reveal that MWNTs are uniformly coated by copper and the diameters of the prepared MWNTs-encapsulated Cu nanowires range from 50 to 150 nm and the lengths are up to several micrometers. These MWNTs-containing Cu nanowires could effectively improve the hardness of the Y−Ba−Cu−O without sacrificing its superconductivity. The Vicker's hardness of the Y−Ba−Cu−O is reinforced by ∼20% after 5 wt % of MWNTs incorporation. This study presents the first result that demonstrates the feasibility of the reinforcement of brittle YBaCuO superconductor by using MWNTs.