Zero thermal expansion ZTE

The expansion of chemical bonds with increasing temperature leads the vast majority of known solids to expand with heating (positive thermal expansion, PTE), a property once thought to be an immutable law of nature. A relatively small number of materials are known that defy this expectation and contract upon heating i.e. display negative thermal expansion, NTE) or are temperature-invariant i.e. display zero thermal expansion, ZTE). These novel behaviours arise due to a range of physical mechanisms that include magnetostriction and, most... 

Materials that do not expand at all as the temperature rises, zero thermal expansion (ZTE) materials, would be of value for many purposes, especially in microelectronic devices that may become warm due to power consumption. For this reason, materials that show ZTE are being actively sought. In the past, a ZTE solid could be constructed by using a composite of two materials, one showing thermal contraction and one showing thermal expansion. However, composite materials often have accompanying drawbacks in use, and a number of solids have now been fabricated that show virtually no expansion at all as the temperature rises. 

---