Using ab initio techniques we examine the structural properties and energetics of novel nanotip and nanocone materials based on silicon carbide nanotubes. The effect of various structural and topological defects on the highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) gap and the stability of these tips are investigated. The HOMO-LUMO gaps range from zero to 2.0 eV due to the defects, providing possible applications in band gap engineering. These tips which combine the elastic and mechanical properties of nanotubes with the stiffness of silicon carbide materials can find applications as atomic force microscopy and scanning tunneling microscopy probes.
Bibliographical noteFunding Information:
The present work is supported through grants by NSF (ITR-0221916), DOE (00-63857), U.S.-ARO (W911NF-05-1-0372), and the European Social Fund and National Resources-EPEAK II-IRAKLITOS and PYTHAGORAS.