Multi-scale electrical response of silicon nitride/multi-walled carbon nanotubes composites

J. González-Julián (1) , Y. Iglesias (1) , A.C. Caballero (1) , M. Belmonte (1) , L. Garzón (2) , C. Ocal (2) , P. Miranzo (1) , M.I. Osendi (1)

1 Institute of Ceramics and Glass
2 ICMAB - Institut de Ciència de Materials de Barcelona

Dense silicon nitride (SiN) composites with various amounts (0 - 8.6 vol%) of multi-walled carbon nanotubes (MWCNTs) are electrically characterised by combining macroscopic dc-ac and nanoscale conductive scanning force microscopy (C-SFM) measurements. In this way, a coherent picture of the dominant charge transport mechanisms in SiN/MWCNTs composites is presented. A raise of more than ten orders of magnitude in the electrical dc conductivity compared to the blank specimen is measured for MWCNTs contents above 0.9 vol%. Semiconductor and metallic-like behaviours are observed depending on both the temperature and the MWCNTs content. Macroscopic measurements are further supported at the nanoscale by means of C-SFM. The metallic-type conduction is associated to charge transporting along the nanotube shells, whereas the semiconductor behaviour is linked to hopping conduction across nanotube-nanotube contacts and across intrinsic defect clusters within the nanotubes.

Mots clés: A. Carbon nanotubes; A. Ceramic-matrix composites (CMCs); B. Electrical properties; D. Atomic force microscopy (AFM); Silicon nitride

Domaines: Matériaux

J. González-Julián, Y. Iglesias, A.C. Caballero, M. Belmonte, L. Garzón, et al.. Multi-scale electrical response of silicon nitride/multi-walled carbon nanotubes composites. Composites Science and Technology, 2010, 71 (1), pp.60. ⟨10.1016/j.compscitech.2010.10.004⟩. ⟨hal-00702317⟩