ROLLED-UP PERMALLOY NANOMEMBRANES WITH MULTIPLE WINDINGS

Abstract

We fabricated Permalloy ( Fe 19 Ni 81) nanomembranes rolled-up into compact three-dimensional architectures and experimentally investigated their magnetic and magneto-electric responses. When a magnetic nanomembrane is rolled-up, an additional magnetostatic interaction between the multiple windings emerges. Such kind of magnetostatic interaction, unique to the rolled-up magnetic nanomembranes and not accessible in any other magnetic architecture, is addressed for the first time in this study. An important feature of rolled-up tubes with multiple windings is that the inner and outer windings are formed by a single magnetic sheet; the spin configuration therefore must be continuous. The magnetostatic interaction induces anti-parallel alignment of the spins within adjacent layers of a rolled-up nanomembrane. The interplay between the magnetostatic interaction due to geometrical transformation and the exchange coupling in the film results in a stabilization of stripe domain patterns.