Heat-capacity study of one liquid-crystal compound with smectic-Ahexatic-Bcrystal-B transition

High-resolution heat capacity measurements have been carried out in the smectic-Ahexatic-Bcrystal-B transitions of the compound 4-propionyl-4-(n- heptanoyloxy)azobenzene. Qualitatively, the heat-capacity anomalies of this smectic-Ahexatic-Bcrystal-B transition sequence mimic those of the smectic-Csmectic-Ismectic-G transition of racemic 4-(2-methylbutyl)phenyl-4-(n -nonyloxy)biphenyl-4-carboxylate. The heat-capacity data near the smectic-Ahexatic-B transition are broad and asymmetric and cannot be fitted with a power-law expression.