AIP Advances (Jun 2017)

Ferromagnetic layer thickness dependence of the Dzyaloshinskii-Moriya interaction and spin-orbit torques in Pt\Co\AlOx

  • R. Lo Conte,
  • G. V. Karnad,
  • E. Martinez,
  • K. Lee,
  • N.-H. Kim,
  • D.-S. Han,
  • J.-S. Kim,
  • S. Prenzel,
  • T. Schulz,
  • C.-Y. You,
  • H. J. M. Swagten,
  • M. Kläui

DOI
https://doi.org/10.1063/1.4990694
Journal volume & issue
Vol. 7, no. 6
pp. 065317 – 065317-7

Abstract

Read online

We report the thickness dependence of the Dzyaloshinskii-Moriya interaction (DMI) and spin-orbit torques (SOTs) in Pt\Co(t)\AlOx, studied by current-induced domain wall (DW) motion and second-harmonic experiments. From the DW motion study, a monotonous decay of the effective DMI strength with increasing Co thickness is observed, in agreement with a DMI originating from the Pt\Co interface. The study of the ferromagnetic layer thickness dependence of spin-orbit torques reveals a more complex behavior. The observed thickness dependence suggests the spin-Hall effect in Pt as the main origin of the SOTs, with the measured SOT-fields amplitudes resulting from the interplay between the varying thickness and the transverse spin diffusion length in the Co layer.