Tracing Memory in Polycrystalline Ferromagnetic Shape‐Memory Alloys

In situ high-energy X-ray diffraction experiments reveal the influence of various microstresses and grain orientations on the memory effect in polycrystalline Ni2MnGa ferromagnetic shape-memory alloys during phase transformation (see figure). The “memory” of grain orientation and intergranular stress is evident; however, the microscale “memory” is degraded due to the existence of the intragranular stress.