Raman spectra of ferroelectric liquid crystal (FLC) D-4-(2-methylbutox
y) phenyl 4-decyloxybenzoate (MBOPDOB) are recorded. All the vibration
al modes are assigned, and their vibrational characteristics are studi
ed. It is found that the s-cis and the s-trans conformers of the ester
group coexist in the crystal phase at room temperature. By temperatur
e-dependent measurements, the line shape changes due to the transition
of the ester group conformation near the crystal-Sm C phase transiti
on point are examined.