Spin pumping and spin torque in interfacial tailored Co2FeAl/\b{eta}-Ta layers

TL;DR

This study demonstrates enhanced spin-mixing conductance and efficient spin torque control in Co2FeAl/eta-Ta heterostructures with tailored interfaces, promising for energy-efficient spintronic devices.

Contribution

It provides detailed measurements of spin transport parameters and shows how interface tailoring improves spin transfer efficiency in Co2FeAl/eta-Ta layers.

Findings

Enhanced spin-mixing conductance with interface tailoring

High current modulation of damping (~2.1%) at 1×10^9 A/m^2

Quantified spin Hall angle and spin diffusion length in heterostructures

Abstract

The Heusler ferromagnetic (FM) compound Co2FeAl interfaced with a high-spin orbit coupling non-magnetic (NM) layer is a promising candidate for energy efficient spin logic circuits. The circuit potential depends on the strength of angular momentum transfer across the FM/NM interface; hence, requiring low spin memory loss and high spin-mixing conductance. To highlight this issue, spin pumping and spin-transfer torque ferromagnetic resonance measurements have been performed on Co_2FeAl/\beta-Ta heterostructures tailored with Cu interfacial layers. The interface tailored structure yields an enhancement of the effective spin-mixing conductance. The interface transparency and spin memory loss corrected values of the spin-mixing conductance, spin Hall angle and spin diffusion length are found to be 3.40 \pm 0.01 \times 10^{19} m^{-2}, 0.029 \pm 0.003, and 2.3 \pm 0.5 nm, respectively. Furthermore, a high current modulation of the effective damping of around 2.1 % has been achieved at an applied current density of 1 \times 10^9 A/m^2 , which clearly indicates the potential of using this heterostructure for energy efficient control in spin devices