Pressure and polarization-angle dependent Raman spectra of aligned single-wall carbon nanotubes in AlPO{sub}4-5 crystal channels

摘要

We investigated aligned single-wail carbon nanotubes (SWNTs) with small diameters (≈ 4A) grown in AlPO{sub}4 - 5 crystal channels. The phonon frequencies of the band at ≈ 1600cm{sup}(-1) were studied as a function of applied external pressure. We analyze the obtained pressure dependences in terms of the elastic continuum model. Polarized Raman spectra at different wavelengths were taken at different angles of the electric field polarization vector with respect to the nanotube axis. We found the scattering intensity to be at maximum for laser light polarized parallel to the channel direction while it is highly suppressed for polarization perpendicular to the channels. This is consistent with a resonant absorption as a first step in the Raman scattering process and only A{sub}(l(g)) symmetry scattering.