抄録
The nematic-isotropic phase transition in a very thin homeotropic cell is studied in the framework of Maier-Saupe model. The transition is of the first order for the system with thickness larger than a critical thickness, while the continuous change occurs at the thinner system. The nonuniformity due to boundary walls is described in terms of an effective field which is conjugate to an order parameter, and behavior of the system is studied by analysing the locus of the effective field on the phase diagram of the bulk. The mechanism of continuous change from the high-temperature phase to the low-temperature one is clarified to be mediated by the insertion of an unstable state between them.
