Superelastic Cu68.5Al17.5Mn14 single crystal with an ultra-wide working temperature range for elastocaloric cooling

Superelastic shape memory alloys with elastocaloric cooling ability suitable for working at a broad temperature range are crucially lacking in facing various scenarios of cooling applications. Low-cost Cu-Al-Mn shape memory alloys are very promising candidates because of their low temperature dependence of critical driving stress of martensitic transformation. Here, a <105>A oriented Cu68.5Al17.5Mn14 single crystal is developed based on cyclic heat treatments, showing large superelastic response and elastocaloric cooling ability covering an ultra-wide temperature range spanning from 77 K to 450 K. Such enhanced temperature span also contributes to an exceptional refrigeration capacity of 5012 J kg–1, well surpassing those in the elastocaloric materials reported so far.