论文部分内容阅读
在现代精密器件中,因存在热梯度,材料的热膨胀成为一个重要的影响因素。通常材料受热后因化学键的伸长而产生膨胀,而仍有一些材料显示异常的(低的或负的)热膨胀特性,这些特性值得深入研究,并以期设计具有应用可能的热膨胀系数可控的材料。众所周知,材料的异常热膨胀特性与框架构造化合物中的晶体结构常存在密切关系。近年来,人们对AMo2O8,APO4,A2Mo3O12类系列框架构造化合物进行了研究,以了解晶体结构对其热膨胀特性和相转变过程的影响。本文综合评述了影响这类材料热膨胀特性和相转变过程相关的结晶学研究结果。
In modern precision devices, the thermal expansion of the material becomes an important factor due to the thermal gradient. Often, the material expands due to the elongation of the chemical bond when heated, while some materials exhibit abnormal (low or negative) thermal expansion characteristics that warrant further study and the design of materials with controllable CTEs . It is well-known that the abnormal thermal expansion characteristics of materials are closely related to the crystal structure in the framework of the compound. In recent years, the framework of AMo2O8, APO4, A2Mo3O12 series of structural compounds were studied to understand the crystal structure of its thermal expansion characteristics and phase transition process. This review summarizes the results of crystallographic studies that have been conducted in relation to the thermal expansion characteristics and the phase transition of these materials.