Large emergent magneto-inductance effect in NiFeCu thin films on flexible polyimide substrates at room temperature

We investigate the emergent magneto-inductance (EML) effect in NiFeCu thin films on ultra-smooth flexible polyimide substrates at room temperature, using an AC current and a stepwise external magnetic field. A large EML exceeding 3.4 μH is observed in Ni79Fe18Cu3, which has thin-film structures without specific spin textures in bulk materials. The observed EML is inversely proportional to the frequency and cross-sectional area, including film thickness and width. Our theoretical calculations reveal that this large EML originates from the spin motive force induced by the transient domain wall motion. Crucially, the enhancement is primarily attributed to a significant reduction in the domain wall pinning potential, in which the hard-axis magnetic anisotropy decreases.