Tuning the magnetodynamic properties of all-perpendicular spin valves using He+ irradiation

TL;DR

This study demonstrates how He+ ion irradiation can precisely tune the magnetodynamic properties of all-perpendicular spin valves, affecting magnetic anisotropy, damping, and GMR, enabling customizable magnetic configurations.

Contribution

It introduces a method to control magnetodynamic properties of spin valves via He+ irradiation, revealing tunable magnetic states and improved damping.

Findings

Magnetic anisotropy decreases with increased He+ fluence.

Magnetic damping and inhomogeneous broadening improve substantially.

GMR decreases linearly with increasing fluence.

Abstract

Using He+ ion irradiation, we demonstrate how the magnetodynamic properties of both ferromagnetic layers in all-perpendicular [Co/Pd]/Cu/[Co/Ni] spin valves can be tuned by varying the He+ ion fluence. As the perpendicular magnetic anisotropy of both layers is gradually reduced by the irradiation, different magnetic configurations can be achieved from all-perpendicular, through orthogonal, to all in-plane. In addition, both the magnetic damping and the inhomogeneous broadening of the Co/Ni layer improve substantially with increasing fluence. GMR of the spin valve is negatively affected and decreases linearly from an original value of 1.14% to 0.4% at the maximum fluence of 50*10^14 He+/cm^2.