Scaling of thermal hysteresis at nematic-smectic- A phase transition in a binary mixture

The photon transmission method was applied to study the scaling of thermal hysteresis at the nematic-smectic-A transition in a binary mixture of 4-ethoxy-4(')-(6-vinyloxyhexyloxyl) azobenzene monomer, smectogen, and 4-hexoxy-3(')-methly-4(')-(6-acryloyloxyhexyloxy) azobenzene. The thermal hysteresis loops were obtained under linearly varying temperature. It has been found that the area A of the hysteresis loops scales with the temperature scanning rate R as A=A(0)+bR(n) with the exponent n equal to 0.692, which is consistent with the (Phi(2))(3) field theoretical model value within the experimental resolution.