Multiwalled carbon nanotube/BaTiO3 nanocomposites: Electrical and rectification properties

Abstract

Multiwalled carbon nanotube (MWNT)∕BaTiO3 functional nanocomposites were fabricated via the spark plasma sintering technique. The resistivity of MWNT∕BaTiO3 nanocomposites was found higher than that of MWNT-free BaTiO3 ceramics. In addition, the temperature dependence of resistivity showed abnormal metallic conductance behavior in the 1wt.% MWNT∕BaTiO3 nanocomposite. It was proposed to be due to the additional subgrain boundary between MWNT and BaTiO3 matrix, which led to transformation from an impurity-scattering mechanism to a dominant lattice-scattering mechanism in the MWNT∕BaTiO3 nanocomposites as the content of carbon nanotubes increased. Based on observed unique electrical properties, bilayer ceramics stacked by one layer of MWNT-free BaTiO3 and another layer of MWNT∕BaTiO3 nanocomposite were fabricated and showed excellent rectification property.