Manufacture and electrical properties of multiwalled carbon nanotube/BaTiO3 nanocomposite ceramics

Abstract

In this paper, we report that novel multiwalled carbon nanotube (MWNT)/BaTiO₃ nanocomposite ceramics were successfully fabricated via a hot-press sintering approach. Well dispersed MWNT–BaTiO₃ composite powders were prepared by primarily synthesizing a new BaTiO₃–MWNT hybrid material and then mixing it with tetragonal BaTiO₃ nanoparticles. This new BaTiO₃–MWNT hybrid material was characterized by XRD, TEM, and IR methods. High density MWNT/BaTiO₃ nanocomposite ceramics were obtained through a hot-press sintering approach using these well-dispersed MWNT–BaTiO₃ composite powders. The electrical properties of MWNT/BaTiO₃ nanocomposite ceramics were measured and analyzed. Interestingly, the conductivity of MWNT/BaTiO₃ nanocomposite ceramics was found to decrease steadily as the amount of MWNTs added increased. Meanwhile, the BaTiO₃ semiconductor transformed from n-type to p-type after doping with carbon nanotubes. We attribute these phenomena to the formation of a Schottky barrier constructed at the carbon nanotube–matrix contact.