Preparation and Electrical Properties of MWNTs/Al2O3 Ceramics Composites

Abstract

In this work, MWNTs/Al₂O₃ composites were prepared by mixing multi-walled carbon nanotubes (MWNTs) and alumina. The MWNTs/ Al₂O₃ composites were obtained by hot pressing sintering in vacuum atmosphere, which had good electric conductivity, the addition of carbon nanotubes were 0.1 wt % alumina, 0.3 wt % and 0.5 wt %. The results indicated that the MWNTs/Al₂O₃ composites, which were formed by addition of 0.3 wt % carbon nanotubes, had the minimum resistivity value and the resistivity value could reach to 101 W cm. Compared with the pure Al₂O₃, the resistivity value lower 5 times. The SEM pictures showed that carbon nanotubes wrapped alumina particles in the form of aggregates. They formed a conductive network in the alumina grain boundaries, so that they could lower resistivity value and improve its electrical conductivity. We also analyzed the MWNTs/Al₂O₃ composites conductive mechanism and showed the conductivity model.