Spin pumping and inverse spin Hall effect in CoFeB/IrMn heterostructures

Abstract

High spin to charge conversion efficiency is a requirement for spintronic devices, which are governed by spin pumping and the inverse spin Hall effect (ISHE). In the last decade, ISHE and spin pumping have been heavily investigated in ferromagnet/heavy metal (HM) heterostructures. Recently, antiferromagnetic (AFM) materials have been found to be a good replacement for HMs because AFMs exhibit terahertz spin dynamics, high spin-orbit coupling, and absence of the stray field. In this context, we have performed the ISHE in CoFeB/IrMn heterostructures. Spin pumping studies are carried out for Co 40 Fe 40 B 20 (12 nm)/Cu(3 nm)/ Ir 50 Mn 50 (t nm)/AlO x (3 nm) samples where t value varies from 0 to 10 nm. Damping in all the samples is higher than in the single layer CoFeB which indicates that spin pumping due to IrMn is the underneath mechanism. Further, the spin pumping in the samples is confirmed by angle dependent ISHE measurements. We have also disentangled other spin rectifications effects and found that the spin pumping is dominant in all the samples. From the ISHE analysis the real part of spin mixing conductance (g ↑↓ r ) is found to be 0.704 ± 0.003 × 10 18 m −2 .

Spin dynamics and inverse spin Hall effect study in the metallic Pt/NiMn/CoFeB system

“…The details of the set-up can also be found elsewhere. 10,[13][14][15][16][17][18][19][20] 3 Results and discussion Resonance field (H res ) and linewidth (DH) are evaluated from the ferromagnetic resonance spectra. The FMR data (see Fig.…”

Antiferromagnetic Inverse Spin Hall Effect

“…ISHE occurs in the heavy metal layer with strong spin-orbit coupling (SOC) for the spin-to-charge conversion. Antiferromagnets (AFMs), such as Mn 3 Ga [8] and IrMn, [9] are later found to be effective for the ISHE, where only strong SOC was taken into account. Recently, ISHE was found to be relevant to the magnetization direction in a magnet, [10][11][12][13][14][15] which is named as the magnetization-dependent inverse spin Hall effect.…”

Heavy metal deposition temperature tuned spin pumping efficiency control in permalloy/tantalum bilayers

“…This can be understood by the fact that as the spin pumping increases there is loss of spin angular momentum of the interfacial ferromagnetic layer through spin transfer to the HM layer which leads to increased magnetic damping [36]. Furthermore, the spin pumping efficiency for Py/Ta samples were evaluated by calculating the spin mixing conductance (g ↑↓ )in the limit of negligible spin black flow, using the formula [36,43]:…”