ultrastable material

ultrastable material

[¦əl·trə¦stā·bəl mə′tir·ē·əl]
(materials)
A material having extremely low thermal expansivity, extremely high temporal stability, and high stiffness-to-density ratio.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.