Multilevel nonvolatile memory based on the hysteretic giant magnetoimpedance effect of heterogeneous magnetic laminate

This work investigates the asymmetric and hysteretic GMI effect of two-phase heterogeneous magnetic laminate consisting of Ni/Fe30Ni45Co18Si2B5/micro-planar coil/Fe30Ni45Co18Si2B5/Ni for nonvolatile memory application. Since the magnetostrictive Ni ribbon produces the remanent magnetoelastic and magnetostatic fields to the neighboring soft amorphous magnetic alloy (Fe30Ni45Co18Si2B5) when the external dc magnetic field is removed, the proposed laminate manifests multi-level remanent impedances depending on the previously applied magnetic field. And the maximum nonvolatile GMI ratio of 130% is obtained at 400 kHz frequency. Furthermore the laminate can function as multilevel nonvolatile memory, which consumes zero standby power without losing data. (C) 2019 The Japan Society of Applied Physics