Analysis of phase transitions by photothermal probe beam deflection

Abstract
A recent photothermal technique has been used to study the smectic A-nematic and nematic-isotropic phase transitions in 4-n-octyl-4prime;-cyanobiphenyl and in binary mixtures of 4-n-octyl- and 4-n-octyloxy-4prime;-cyanobiphenyl. A numerical analysis shows that both amplitude and phase of the photothermal signal are sensitive to the change of certain thermal parameters for the sample.