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一、前言 在材料化学中,一个很重要的问题是确定材料中加入多少量的别种离子或离子团以取代原来的离子,而不使原来的结构产生变化。这是寻找新材料的一个重要途径。 目前,迅速发展的核能源中,一个迫切需要解决的重大研究课题是核废料处理。而将核废料用固体反应引入一种稳定的矿物,如硅灰石,可能是解决这一课题的一个十分有希望的途径。 以前的研究指出,Sr~(2+)取代Ca~(2+)可以使链状硅灰石(CaSiO_3)(照片1a)成为环状的假硅灰石结构(照片1b);锗取代硅氧四面体中的硅可以形成环-链结构的共生长。 从几何因素上考虑,铝氧四面体[AlO_4]和硅氧四面体[SiO_4]大小相近。因此用[AlO_4]
I. INTRODUCTION In material chemistry, a very important issue is to determine how much other ions or groups of ions are added to the material to replace the original ions without changing the original structure. This is an important way to find new materials. At present, one of the major research topics urgently needed to solve in the rapidly developing nuclear energy industry is nuclear waste disposal. The introduction of a solid reaction of nuclear waste into a stable mineral, such as wollastonite, may be a promising solution to this problem. Previous studies have shown that substitution of Sr 2+ for Ca 2+ results in a ring-shaped pseudolio-wopite structure (Photo 1b). Chain-like wollastonite (photo 1a) Silicon in the tetrahedra can form a ring-chain structure of co-growth. Considering geometrically, the sizes of AlO 4 and Si 4 SiO 4 are similar. Therefore, with [AlO_4]