Spin pumping using an Ni80Fe20 thin film annealed in a magnetic field

TL;DR

This study demonstrates that annealing an Ni80Fe20 thin film in a magnetic field enhances spin pumping efficiency, leading to stronger inverse spin-Hall effect signals and higher spin current densities in Pd layers.

Contribution

The paper introduces a magnetic field annealing process for Ni80Fe20 films that improves spin pumping performance and spin current generation efficiency.

Findings

Annealing increases the electromotive force due to ISHE by 30%.

Maximum spin injection occurs when magnetic moments align with the external field.

Magnetic field annealing is a practical method to boost spin current density.

Abstract

Spin pumping controlled with the ferromagnetic resonance of an Ni80Fe20 thin film annealed in a magnetic field was performed in order to investigate the simple and efficient generation method of the pure spin current. At the spin-pumping using the Ni80Fe20 on an annealed Pd/Ni80Fe20 stacked structure, the electromotive force due to the inverse spin-Hall effect (ISHE) in the Pd was found to be 30% stronger than that without annealing. When the angle between the directions of localized magnetic moments in the Ni80Fe20 film and the external magnetic field in the spin-pumping is zero, the spin injection efficiency into the Pd layer, i.e., the spin current density generated in the Pd layer can be the maximum. The annealing in a magnetic field is a convenient technique for increasing the spin current density generated by the spin pumping.