Non-conventional Strain Glasses

Strain glass, a short-range strain-ordered state of martensitic/ferroelastic material, has drawn much interest in recent years due to its novel properties unattainable in martensitic materials. So far, typical or conventional strain glasses have been reported to be characterized by nano-sized martensitic domains formed from a homogeneous parent phase matrix. This article reviews the recent progress in “non-conventional strain glass,” which is different from the conventional strain glasses reported so far. We first introduce a “reentrant strain glass,” where strain glass nanodomains are formed from a martensitic phase instead of from a parent phase. The reentrant strain glass can show low modulus and high damping properties over a wide temperature range. The second non-conventional strain glass is a “spinodal strain glass” produced by a spinodal decomposition in its early stage. This unique strain glass is formed from a nanoscale compositionally inhomogeneous parent phase (by spinodal decomposition). The spinodal strain glass demonstrates high-damping Elinvar effect over an ultrawide temperature range. These non-conventional strain glass alloys may have potential for novel applications as new structural–functional materials.