矿物热膨胀的晶体化学研究综述  

An Overview of Crystal Chemistry Study on Thermal Expansion of Minerals

作　　者：李锁在[1] 廖立兵[1] 

机构地区：[1]中国地质大学材料科学与工程学院,北京100083

出　　处：《高校地质学报》2000年第2期333-339,共7页Geological Journal of China Universities

摘　　要：热膨胀是矿物材料的重要属性之一 ,对它的研究在矿物学及材料科学中具有重要意义。前人关于矿物的热膨胀系数和晶体化学参数之间关系的研究表明 ,矿物的结构、成分、化学键及原子价态、配位数、外层电子结构等对热膨胀系数都有不同程度的影响。晶体化学方法是研究矿物热膨胀系数的有效方法 ,但由于矿物的热膨胀系数和晶体化学参数之间的定量关系尚未完全弄清 ,目前仅仅能对简单结构矿物的热膨胀系数进行计算 ,结构、成分较复杂的矿物的热膨胀系数计算尚缺乏好的晶体化学模型。为达到精确计算矿物热膨胀系数的目的 ,必须对矿物按照晶体化学特性进行分类。在分类的基础上 ,把晶体化学方法和理论计算方法有效地结合起来。矿物的热膨胀性可按照受热时结构有无旋转划分为键膨胀型和结构旋转型 ,过渡金属阳离子所形成的化合物根据d电子层电子云的分布进行分类。通过以上的分类 ,在计算不同类型矿物热膨胀系数时 ,可按矿物类型处理。对键膨胀型的矿物只需估计键的膨胀情况 ,而对于结构旋转型除考虑键的膨胀性以外还要考虑配位多面体旋转的情况。Thermal expansion is one of the important properties of m inerals and o f theoretical and practical significance. This paper is a review of the crystal chemistry studies on mineral thermal expansion. With some examples, the correlat ions between the thermal expansion coefficients of minerals and the types of cr ystal structures, the nature of chemical bonds, the valencies of ions , the interionic distances, the percentage ionic characters, the electronic conf igurations of ions and the chemical compositions are discussed and summarised . The crystal chemistry approach has been used in the calculation of the th ermal expansion coefficients for minerals with simple structures and composition s. Models suitable for calculation of the thermal expansion coefficients for m inerals with complex structures and compositions are to be developed. To calculate the thermal expansion coefficients of minerals in a wide range, the minerals should be classified according to their crystal chemistry properties. In the light of framework structures upon heatig during which the polyhedra are tilted or fixed, the thermal expansion properties can be divided into two catego ries, the bond-length expansion caterory and the structures with tilts category . The transition metal cation compounds should be considered separately. Based on the above-mentioned types, for the bond-length expansion category only the expansion of bonds in the framework should be considered, but for the structur e with tilts category both the expansion of bonds and the tilts of the polyhedra in framework should be considered.

关 键 词：热膨胀系数 晶体化学 晶体化学参数 矿物 

分 类 号：P574.1[天文地球—矿物学] P573[天文地球—地质学]