Kinetics of crystalline to smectic A (K--SmA) phase transition of 4-decyl-4-biphenylcarbonitrile liquid crystal

In this study crystalline to smectic A (K--SmA) phase transition of 4-decyl-4-biphenylcarbonitrile (10CB) liquid crystal was studied using calorimetric technique. Two types of scans -- heating and cooling were performed from 250 to 350 K, and from 350 to 250 K. A clear difference in K--SmA phase transition was observed between heating and cooling scans. An inclination effect in K--SmA transition was observed on cooling which is completely absent on heating. The inclination of the K--SmA transition peak increased and showed the presence of a heating rate kinetics in the K-SmA transition which can be explained in terms of the presence of time lag and increased activation based on the density and nature of the material.