Kittel型反铁电相变的序参量

Order Parameter of Kittel Antiferroelectric Phase Transition

对于Kittel型反铁电相变，选择一个亚晶格的自发极化矢量P1/2或反极化参量P作为序参量是不合适的．本文具体讨论了相变前后对称性的变化，并由居里原理，给出此类相变序参量的正确形式，即，具有Cni的对称性．轴矢量R能很好地反映相变前后对称性的变化，可选作Kittel型反铁电相变的序参量．

It is unsuitable to choose spontaneous polarization vector P1/2 of a subcell and antipolarization parameter P as the order parameter for Kittel antiferroelectric phase transition. The changes of symmetry are discussed in detail, according to Curie principle, the proper form is given. The definition of axial vector R is as follows: and can reflect the changes of symmetry perfectly having Cni symmetry,which can be chosen the order parameter of Kittel antiferroelectric phase transition.