抄録
A global phase diagram of Maier–Saupe model for nematic–isotropic phase transition on the external field versus temperature plane is obtained, where due to non-polar property of the system two sets of order parameters and the conjugate fields are required to describe completely the phenomena. The phase diagram is argued in the context of a similarity of the model to the three-state Potts model. Inhomogeneity at the thin system sandwiched by parallel walls is expressed in terms of an effective external field, where effects due to homeotropic, homogeneous, planer and oblique anchoring walls are classified systematically. A shift of the transition temperature together with the property of phase transition is explained systematically on the basis of the phase diagram of bulk system, where the changes of the order of phase transition is related to a critical point and a tricritical one appearing in the phase diagram.
