Fig. 1. (a, b) X-ray diffraction profiles of 6Cr martensite alloy and 9Cr strain glass alloy, respectively. (c, d) TEM images and the corresponding diffraction pattern of 6Cr martensite alloy and 9Cr strain glass alloy, respectively. The red circle indicates the incommensurate near 1/3 reflection.

Fig. 2. DMA and DSC results of 6Cr martensite alloy (a1, a2) and 9Cr strain glass alloy (b1, b2). The inset in (b1) shows the Vogel-Fulcher fitting of Tg (tanδ peak temperature).

Fig. 3. The ΔL versus temperature curves under different external stress for martensite alloy 6Cr (a, b), and strain glass alloy 9Cr (c, d).

Fig. 4. The $\text{ }\!\!\Delta\!\!\text{ }{{S}_{\text{iso}}}$ versus temperature under different external stress for 6Cr martensite alloy (a, b) and 9Cr strain glass alloy (c, d).

Fig. 5. The ΔL and $\text{ }\!\!\Delta\!\!\text{ }{{S}_{\text{iso}}}$ versus temperature curves on heating under different external stress of martensite alloy 6Cr (a, c), and strain glass alloy 9Cr (b, d)), respectively. Each curve is obtained under the temperature-field history of zero field cooling.

Fig. 6. The schematic evolution of domain configurations upon heating for a strain glass alloy with history of field cooling (a-c), and that with history of zero field cooling (d-f). (g) The length change (ΔL) versus temperature during heating for the two cases. For (a) to (c) the entropy increases with temperature, as the configuration continually becomes disordered. From (d) to (e), the randomly oriented domains align along the external stress, leading to a decrease of entropy upon heating, giving rise to an “inverse" elastocaloric effect. From (e) to (f) the thermal energy (${{k}_{\text{B}}}T$) dominates and leads to the similar situation with field cooling history from (b) to (c).