Direct Measurement of Percolation Probability in Multi-walled Carbon Nanofiber Polymer Nanocomposites
Abstract not provided.
Publications
Direct measurement of the percolation probability in carbon nanofiber-polyimide nanocomposites
Proposed for publication in the Physical Review Letters.
We present the first experimental measurement of the geometric critical exponent {beta} associated with the percolation probability, the probability a metallic filler belongs to the conducting network, of an electrical composite. The technique employs conducting-tip atomic force microscopy to obtain a conducting areal density, and is demonstrated on polyimide nanocomposites containing different concentrations of carbon nanofibers. We find {beta} {approx} 1 and t (the exponent for bulk conductivity) {approx} 3. These values are consistent with the predictions for the Bethe lattice and larger than the values predicted in the 3D lattice percolation model. Hence, this electrical composite likely belongs to the same universality class as the Bethe lattice. The ability to measure geometric and transport critical exponents on the same material is critical to drawing this conclusion.
Microscopic Electrical Study of Carbon Nanofiber Composites Using Conducting-tip Atomic Force Microscopy
Abstract not provided.
Au/Ag and Au/Pd Molecular Contacts to GaAs
J. Vac. Sci. Technol. B
Abstract not provided.
Conducting-tip AFM Studies of Multi-Walled Carbon Nanotube/Polyimide Nanocomposites
Abstract not provided.
5 Results