Changes in magnetic scattering anisotropy at a ferromagnetic/superconducting interface

TL;DR

This study investigates how different metal interlayers affect magnetic scattering anisotropy at ferromagnetic/superconducting interfaces, revealing that some metals activate anisotropies and alter magnetoresistance, while others do not.

Contribution

It demonstrates that certain metals induce magnetic scattering anisotropies at ferromagnetic/superconducting interfaces, leading to changes in magnetoresistance, a novel insight into interface spin-flip mechanisms.

Findings

Metals like Ru or Au change the CPP-MR and can reverse its sign.

Some metals such as Cu, Ag, FeMn do not affect the magnetoresistance.

Activation of magnetic scattering anisotropies is linked to spin-flipping at interfaces.

Abstract

We show that some metals and alloys (X = Cu, Ag, FeMn, or Cu and Ag combined with each other), sputtered between ferromagnetic Co and superconducting Nb, produce no change in current-perpendicular-to-plane magnetoresistance (CPP-MR) in a carefully designed CPP-spin-valve. In contrast, other metals (Ru or Au) or combinations (Cu or Ag combined with Au, Ru, or FeMn) change the CPP-MR, in some cases even reversing its sign. We ascribe these changes to activation of magnetic scattering anisotropies at a ferromagnetic/superconducting interface, apparently by strong spin-flipping between the Co and Nb layers.