Magnetic State Modification Induced by Superconducting Response in Ferromagnet/Superconductor Hybrids

TL;DR

This paper investigates how the superconducting response in Nb/Co superlattices influences and modifies the magnetic state of the ferromagnetic layers, revealing complex temperature and field-dependent behaviors.

Contribution

It demonstrates that the magnetic state of ferromagnetic Co layers is altered by the superconducting Nb response, emphasizing the need for a self-consistent analysis of superconductor/ferromagnet hybrids.

Findings

Magnetization behavior depends on temperature, field, and sample history.

Superconducting response modifies the ferromagnet's magnetic state.

A simple model explains the interplay between superconductor and ferromagnet.

Abstract

Magnetization measurements in superconductor/ferromagnet Nb/Co superlattices show a complex behavior as a function of temperature, applied field and sample history. In base to a simple model it is shown that this behavior is due to an interplay between the superconductor magnetization temperature dependence, the ferromagnet magnetization time dependence, and the stray fields of both materials. It is also shown that the magnetic state of the Co layers is modified by the Nb superconducting response, implying that the problem of a superconductor/ferromagnetic heterogeneous sample has to be solved in a self-consistent manner.