准晶体的构筑原理及微粒分数维结构模型

准晶体的原子构造中两个原理在起作用,即二十面体原理和黄金中值原理。二十面体原理是指大小相近的原子形成孤立的十二次配位体时,二十面体配位形式在能量上最有利。黄金中值原理是指在准晶体中原子的排列符合黄金中值律。这两个原理适用于由少量原子构成的体系,也适用于某些生物的结构。运用这两个原理于准晶体微粒,我们获得了最简单的准晶体结构模型。此模型可以解释Al-Mn准晶体的高分辨图的所有细节。此模型与Hiraga模型以及Bursill和彭菊琳模型都不相同。在此模型中Al_(12)Mn二十面体不是共棱的。这一模型具有分数维结构的待征,因此称之为准晶体的微粒分数维结构模型。

BUILDING PRINCIPLES OF QUASICRYSTAL AND THE PARTICLE FRACTAL STRUCTURAL MODEL

Two principles play a role in the atomic structure of quasicrystal, i.e. the icosahedron principle and the golden mean principle. The icosahedron principle means that when the atoms similar in sizes and form isolated ligands with the coordination number is twelve, the formation of icosahedron ligand is favour in energy, and the golden mean principle means that the arrangement of atoms in quasicrystal conforms the golden mean rule, i.e. the arrangement of atoms according to the order of Fibonacci series. The two principles are suitable for the system composed by few atoms and also for some biological structures. Applying the two building structural principles to quasicrystal particles, we could obtain the most simple structural model of quasicrystals and explain all details of the high-resolution electron microscopic image of the Al-Mn quasicrystal. The model is unsimilar with Hiraga's model and Bursill and Peng Ju-lin's model. In our model, the Al12Mn icosahedron is isolated but not sharing edges. The model has the characteristic of fractal structure, therefore, we call it the particle fractal structural model.