Figure 5.

Polarized-light Raman spectra recorded at two different perpendicular polarizations, XX and XY. The Raman G line spectra SXX and SXY correspond to the unstretched samples; EXX and EXY, to stretched samples with 10% elongation. One may observe how the intensity of the relationship after elongation, EXX/EXY ≈ 2.76, is increased respectively similar to that before elongation, SXX/SXY ≈ 2.03, which indicates a preferred orientation by stretching. Furthermore, the relation D/G remains unchanged, indicating that stretching does not appreciably introduce defects.