Raman Spectroscopy of Individual Carbon Nanotubes Under Strain
S.B. Cronin, M. Tinkham, and E. Demler
Raman spectroscopy of individual semiconducting carbon nanotubes is used for the first
time to measure vibrational frequencies vs. strain. The strain is
induced by bending the nanotubes with an AFM tip while the ends of
the nanotubes are held fixed by metal electrodes, thus converting
the transverse displacement to an elongation. Under strain of 1–2%,
we observe the vibrational frequency to decrease by up to 40cm–1.
The Raman peaks shift back toward their original positions over
a time period of order one week, implying strain relaxation over
a similar period.