Giant elastic response and ultra-stable elastocaloric effect in tweed textured Fe-Pd single crystals

Abstract The limit of elastic deformation in conventional metals and alloys is usually within 0.1%. When deformed further, these materials show plastic deformation effects, which are a consequence of dislocation movements. Here, we report that a much larger elastic-like strain of more than 4% can be achieved in a tweed textured Fe-Pd single crystal under a compressive stress of 300 MPa. We show that this giant elastic response gives rise to significant and homogenous elastocaloric effect (∼4.1 K) that can sustain 106 or even more mechanical cycles without degradation. The large and stable elastic-like strain in Fe-Pd originates from the continuous and reversible structural change associated with the tweed texture under stress as confirmed by the in-situ high energy X-ray diffraction tests. Phase field simulation also confirms this giant elastic response and ultra-stable elastocaloric effect under a compressive stress in the Fe-Pd alloy.