## 抄録

The orientational ordering in a system of dipolar molecules located on a trigonal lattice is studied in the eight-sublattices approximation. Our concrete example is SO_{2} molecules in β-hydroquinone clathrate. It is assumed that the molecules interact with each other via effective dipole-dipole interactions, and that the crystal field acting on those molecules is of the form W_{A} = C_{COS}[ν(φ-δ_{A})], where φ is a rotational angle and A is a sublattice number. If ν is an odd integer, we assume that δ_{A} may different for different A. The mean electric field which depends on the depolarization field is obtained. Various cases of C, ν, δ_{A} are investigated. Results are as follows: the possible dipole arrangement is antiferroelectric in all cases; the phase transition for ν = 2, 4, 5, 6 is of second order; if ν = 1, no disordered phase occurs; if ν = 3, the phase transition is weakly of first order excep for special cases; the C dependence of the transition temperature is weak unless ν = 2; δ_{A} chiefly determines the equilibrium direction. A comparison with experiment suggests that the low-temperature phase of SO_{2}-β-hydroquinone has ν = 2 or 3, and that interactions between enclosed SO_{2} molecules other than dipole-dipole interactions may be also effective.

本文言語 | 英語 |
---|---|

ページ（範囲） | 1364-1370 |

ページ数 | 7 |

ジャーナル | journal of the physical society of japan |

巻 | 66 |

号 | 5 |

DOI | |

出版ステータス | 出版済み - 5月 1997 |

## !!!All Science Journal Classification (ASJC) codes

- 物理学および天文学一般

## フィンガープリント

「Effects of a Crystal Field on the Orientational Phase Transition in a System of Dipoles: A Mean-Field Study of SO_{2}-β-Hydroquinone Clathrate」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。