Decoupling Magnetoelastic and Magnetostatic Effects in Nanometric Films on Flexible Substrates Under In Situ Biaxial Multicracking

ABSTRACT Flexible magnetoelectronics face a major challenge in maintaining functionality under mechanical strain. This research investigates how biaxial multicracking affects the magnetic properties of nanometric thin films, specifically by separating magnetoelastic from magnetostatic effects. Using a unique experimental platform, we show that in magnetostrictive Co films, the magnetic behavior is dominated by stress‐induced magnetoelastic effects. In contrast, in non‐magnetostrictive films, the magnetic changes only appear once multicracking begins, allowing us to demonstrate the magnetostatic contributions from fragmentation. Our findings reveal that the variation in the saturation field correlates directly with fragment shape. This work demonstrates that fragmentation is not just a failure mechanism but a controllable process whose magnetic effects can be understood and leveraged for designing next‐generation flexible devices.