Progress on abnormal thermal expansion materials

Solid materials usually show expansion or contraction behavior in response to changes in temperature. However, thermal expansion behavior always reduces the stability and safe reliability of precision parts, and even destroys the functional features of the materials. In the fields of optical instruments, microelectronic devices, aerospace and others, we desperately need the materials for which the shape and size keep unchanged with temperature, in order to ensure high dimensional stability, precision and long service life. The low or near zero thermal expansion materials have the performance that their microstructure size can change hardly with temperature and they can keep the volume either thermal dilation or cool shrink in the area of specific temperature, the negative thermal expansion materials have the performance of thermal shrink and cool dilation. Therefore, the research on the abnormal thermal expansion materials has attracted more and more attention. This paper outlines the research and development of abnormal (negative or near zero) thermal expansion materials, especially, focusing on several popular classes in this system. We further discussed the existent problems and the direction of future development in this research field.