Phase diagrams of the transverse Ising model with a four-spin interactionB. H. Teng1, 2 and H. K. Sy2
1 School of Physical Electronics, University of Electronic Science and Technology of China - Chengdu 610054, PRC
2 Department of Physics, National University of Singapore Kent Ridge, Singapore 117542, Republic of Singapore
received 9 December 2005; accepted in final form 22 December 2005
published online 11 January 2006
This paper investigates the phase diagrams of a ferroelectric thin film described by the transverse Ising model with a four-spin interaction. Within the framework of the higher decoupling approximation, the phase diagrams for the first-order and second-order transitions in a ferroelectric thin film are obtained, respectively, while increasing and decreasing temperature. The effects of various parameters and film thickness on the phase diagrams are shown, and the comparison between the higher decoupling approximation and the usual mean-field approximation is illustrated.
77.80.Bh - Phase transitions and Curie point.
75.10.Hk - Classical spin models.
77.55.+f - Dielectric thin films.
© EDP Sciences 2006