Near Zero Coefficient of Thermal Expansion
Beta-Eucryptite without Microcracking
Subramanian Ramalingam and Ivar Reimanis
Summary: A method to produce doped Beta-eucryptite that does not display the normal
problem of microcracking
Description: Researchers at the Colorado School of Mines have developed a method of
producing doped Beta-eucryptite that does not display the normal problem of microcracking.
Beta-eucryptite may be used for applications in which a very low coefficient of thermal
expansion (CTE) is desired such as thermal shock-resistant structures, nanolithography
platforms, and optical windows. The reason that microcracks form is due to the large difference
in CTE between different crystallographic directions. However, the CTE is altered by the dopant
(in concentrations as low as 0.5 molar percent) from a value that is small and negative to a
value that is very small and positive. The CTE alteration is thought to arise because the dopant
modifies the response of the crystal structure to a temperature change.
Main Advantages of this Invention
 No microcracking in the Beta-eucryptite
 Dopant is made from readily available materials
 Slight modification to existing manufacturing
Potential Areas of Application
 Thermal shock-resistant structures
 Nanolithography platforms
 Optical windows
ID number: 12023
Intel ectual Property Status: US 7,696,116 and US
Opportunity: We are seeking an exclusive or non-
exclusive licensee for marketing, manufacturing, and
sale of this technology.
For more information contact:
William Vaughan, Director of Technology Transfer
Colorado School of Mines, 1500 Illinois Street, Guggenheim Hall Suite 314, Golden, CO 80401
Phone: 303-384-2555; e-mail: