Rotator-II to rotator-I phase transition in alkanes

摘要

The rotator-II to rotator-I phase transition in alkanes is studied within Landau theory. The effect of pressure on the transition is also examined. The transition is found to be first orfer, even at elevated pressure, with the transition temperature increasing with pressure. The various thermodynamic quantities are calculated near the transition. The Landau coefficients are calculated for various chain lengths from experimental data. The values of the coeffiients are decreasing with increasing chain length.