Critical heat capacity of antiferroelectric liquid crystal 12BIMF10

Abstract

Heat capacity of the antiferroelectric liquid crystal 12BIMF10 has been measured with both an ac method and a relaxation method. A very sharp heat capacity peak was observed at the Sm-Cα*-Sm-A transition. The excess heat capacity for this transition showed a non-Landau critical behavior. The exponent α determined by a fit with a preasymptotic power-law equation lied 0.10-0.21. The data were also fitted acceptably well with 3D XY exponents when the correction-to-scaling terms up to the second order have been included. These results strongly suggest that the present data reflect a crossover from the 3D XY behavior to the tricritical behavior.