Interfacial magnetic anisotropy controlled spin pumping in Co60Fe20B20/Pt stack

TL;DR

This paper demonstrates how interfacial magnetic anisotropy in CoFeB/Pt stacks can be used to control spin pumping efficiency, enabling tunable pure spin current generation for advanced spintronic devices.

Contribution

It introduces a method to tune spin pumping via interfacial magnetic anisotropy by adjusting ferromagnetic layer thickness in CoFeB/Pt stacks.

Findings

Spin current density increases with in-plane anisotropy field.

Tunable spin pumping effect observed with varying CoFeB thickness.

Interfacial anisotropy enables control over pure spin current generation.

Abstract

Controlled spin transport in magnetic stacks is required to realize pure spin current-driven logic and memory devices. The control over the generation and detection of the pure spin current is achieved by tuning the spin to charge conversion efficiency of the heavy metal interfacing with ferromagnets. Here, we demonstrate the direct tunability of spin angular momentum transfer and thereby spin pumping, in CoFeB/Pt stack, with interfacial magnetic anisotropy. The ultra-low thickness of CoFeB thin film tilts the magnetic easy axis from in-plane to out-of-plane due to surface anisotropy. The Ferromagnetic resonance measurements are performed to investigate the magnetic anisotropy and spin pumping in CoFeB/Pt stacks. We clearly observe tunable spin pumping effect in the CoFeB/Pt stacks with varying CoFeB thicknesses. The spin current density, with varying ferromagnetic layer thickness, is found to increase from 0.11 to 0.24 MA/m2, with increasing in-plane anisotropy field. Such interfacial anisotropy-controlled generation of pure spin current can potentially lead to next-generation anisotropic spin current-controlled spintronic devices.