Raman spectroscopy of PbO-filled single wall carbon nanotubes

Abstract

We investigated single wall carbon nanotubes filled with lead oxide, PbO, by transmission electron microscopy and Raman spectroscopy. It is concluded from the positions of the Raman lines that PbO crystalizes in the orthorombic phase inside the nanotubes. The line position of the most prominent PbO line is downshifted in about 5 cm−1 as compared to the bulk material as a result of the reduced dimensionality. As a consequence of the filling, nanotubes become sensitive to the laser irradiation. At the higher laser power densities, they break up and the free PbO nanowires are left in the sample.