Atomic scale control of spin current transmission at interfaces

TL;DR

This study investigates how inserting an insulating layer affects spin current transmission at ferromagnet/heavy metal interfaces, revealing that spin memory loss is significant mainly in 5d metals with less than half-filled d-shells.

Contribution

The paper provides experimental insights into interface spin transmission mechanisms, highlighting the role of d-shell filling in spin memory loss at ferromagnet/heavy metal interfaces.

Findings

Significant spin memory loss occurs mainly in 5d metals with less than half-filled d-shells.

Insertion of insulating interlayers influences spin current transmission.

Inverse spin Hall voltage measurements confirm the effects of interface modifications.

Abstract

Spin transmission at ferromagnet/heavy metal interfaces is of vital importance for many spintronic devices. Usually the spin current transmission is limited by the spin mixing conductance and loss mechanisms such as spin memory loss. In order to understand these effects, we study the interface transmission when an insulating interlayer is inserted between the ferromagnet and the heavy metal. For this we measure the inverse spin Hall voltage generated from optically injected spin current pulses as well as the magnitude of the spin pumping using ferromagnetic resonance. From our results we conclude that significant spin memory loss only occurs for 5d metals with less than half filled d-shell.