Fabrication of aluminum-carbon nanotube composites and their electrical properties

Aluminum-carbon nanotube (CNT) composites were fabricated by hot-pressing t he respective powders. The microstructural characteristics and the distribu tion of carbon nanotubes in the aluminum matrix were investigated. The elec trical resistivities of the composites were measured fr om room temperature down to 4.2 K. The electrical resistivity at room temperature increases sl ightly with increasing volume fraction of the carbon nanotubes in the alumi num. From room temperature to similar to 80 K all the composites exhibit th e typical metallic decrease or the electrical resistivity upon lowering the temperature. Ar about 80 K their resistivities abruptly drop by more than 90%: at lower temperatures the resistivity does not show any fluctuation. ( C) 1999 Elsevier Science Ltd. All rights reserved.