we recorded the ch-stretching ( 2800-3000-cm-1 ) regions of the raman spectra at various temperatures and employed plots of temperature vs. the intensity of the 2880- or 2930-cm-1 bands relative to that of the 2850-cm-1 feature , i.e. , the ratios i2880/i2850 and i2930/i2850 , to estimate thermal transitions .
C0039476
temperatures
C1521970
feature