Nanosecond S-type Electrical Instability in Carbon-Nanotube–Polymer Composites

Abstract

Composites materials comprising carbon nanotubes (CNTs) embedded in a teflon polymer matrix are synthesized. The diameter and length of the CNTs are 8–10 nm and up to 150 nm, respectively. The SEM technique is used to characterize the morphology of the composites. The electrical properties are studied by recording the I–V characteristics in the nanosecond pulse mode of measurements. The typical I–V curves exhibit an S-type instability. Close to the critical voltage U c , the I–V curves are typical of multi-walled CNTs; above U c , the ohmic I–V behavior resulting from the thermally induced destruction of CNTs is observed. The statistical distribution of the resistance over the sample area is established. The experimentally observed effects are attributed to multi-walled CNTs.