Relaxation mechanism driven by spin angular momentum absorption throughout antiferromagnetic phase transition in NiFe surface oxides

TL;DR

This paper uncovers a new relaxation mechanism in NiFe thin films driven by spin angular momentum absorption during antiferromagnetic phase transitions, revealing temperature-dependent damping behavior.

Contribution

It introduces an alternative explanation for ferromagnetic relaxation involving spin absorption at antiferromagnetic surface layers during phase transition.

Findings

Peak in NiFe damping linked to spin angular momentum absorption

Enhanced damping observed at antiferromagnetic phase transition

Surface oxidation influences magnetic relaxation behavior

Abstract

We report an alternative mechanism for the physical origin of the temperature-dependent ferromagnetic relaxation of Permalloy (NiFe) thin films. Through spin-pumping experiments, we demonstrate that the peak in the temperature-dependence of NiFe damping can be understood in terms of enhanced spin angular momentum absorption at the magnetic phase transition in antiferromagnetic surface-oxidized layers. These results suggest new avenues for the investigation of an incompletely-understood phenomenon in physics.