Location via proxy:   [ UP ]  
[Report a bug]   [Manage cookies]                

Magnetotransport and magnetic textures in Ho/FeCoGd/β-W multilayers

Ramesh C. Budhani, Vinay Sharma, Ezana Negusse, Jacob Casey, Arjun K. Pathak, Jerzy T. Sadowski, and Brian Kirby
Phys. Rev. B 105, 024412 – Published 12 January 2022

Abstract

The enhancement of interfacial Dzyaloshinskii-Moriya Interaction (DMI) in magnetic multilayers results in the stabilization of topological spin textures such as chiral domain walls and skyrmions. Here we report on the evaluation of interface-driven magnetic interactions in a uniquely designed multilayer where each magnetic layer of two antiferromagnetically coupled sublattices of 3d and 4f moments is sandwiched between the layers of β-tungsten and holmium whose spin Hall angles are large but opposite in sign. The atomic and magnetic periodicity of these multilayers is established by polarized neutron reflectivity measurements and the presence of a labyrinth domain spin texture of zero remanence with x-ray photoelectron microscopy. Measurements of the Hall resistivity [ρxy(T,H)] together with static magnetization [M(T, H)] over a broad range of temperature (T) and magnetic field (H) indicate impending compensation between 3d and 4f sublattices at T>350K. These multilayers are characterized by a small (0.04%) but positive magnetoresistance indicative of interface enhanced scattering, and a large (40 nΩ m) and negative anomalous ρxy(T,H) which results from a parallel alignment of 4f moments with the external magnetic field. No distinct scaling is seen between ρxy(T,H), ρxx(T,H), and M(T, H) at temperatures above 200 K where the magnetization develops out of plane anisotropy. The field scans of ρxy at T>200K show a distinct cusp in the vicinity of magnetic saturation. These Hall data have been analyzed in the framework of a model where a distinct topological contribution to ρxy rides over the anomalous Hall resistivities of the 3d and 4f magnetic sublattices. It is suggested that this apparent topological effect results from an interfacial DMI and dominates ρxy(T,H) in the temperature regime where the 3d and 4f lattices are nearly compensated.

  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Received 17 October 2021
  • Revised 22 December 2021
  • Accepted 24 December 2021

DOI:https://doi.org/10.1103/PhysRevB.105.024412

©2022 American Physical Society

Physics Subject Headings (PhySH)

Condensed Matter, Materials & Applied Physics

Authors & Affiliations

Ramesh C. Budhani1,*, Vinay Sharma1, Ezana Negusse1, Jacob Casey2, Arjun K. Pathak2, Jerzy T. Sadowski3, and Brian Kirby4

  • 1Department of Physics, Morgan State University, Baltimore, Maryland 21251, USA
  • 2Department of Physics, SUNY Buffalo State, Buffalo, New York, New York 14222, USA
  • 3Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, USA
  • 4NIST Center for Neutron Research, Gaithersburg, Maryland 20878, USA

  • *Ramesh.budhani@morgan.edu

Article Text (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 105, Iss. 2 — 1 January 2022

Reuse & Permissions
Access Options
CHORUS

Article Available via CHORUS

Download Accepted Manuscript
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×

Images

  • Figure 1
    Figure 1

    (a) Spin splitting between R++ and R demonstrating sensitivity to in-plane sample magnetization parallel to the external field. (b) Model fits to depth profile data for nuclear and magnetic scattering.

    Reuse & Permissions
  • Figure 2
    Figure 2

    X-ray magnetic circular dichroism (XMCD) image taken at the Gd-M5 absorption edge (∼1173 eV) and showing stripelike ferromagnetic domains.

    Reuse & Permissions
  • Figure 3
    Figure 3

    Out of plane magnetization loops of [Ho/FeCoGd/W]n multilayer measured at T=100, 200, 300, and 350 K. The 200, 300, and 350 K loops have been given a rigid shift 0.1, 0.2, and 0.3 T, respectively, for clarity. Inset shows variation of saturation magnetization with temperature (1emu/cm2=10A).

    Reuse & Permissions
  • Figure 4
    Figure 4

    (a) The Hall resistivity of the multilayer as a function of temperature from 2 to 300 K measured at 2, 4, and 8 T magnetic field applied perpendicular to film plane. (b) The longitudinal resistivity as a function of temperature.

    Reuse & Permissions
  • Figure 5
    Figure 5

    (a) Loops of the out of plane field magnetoresistance (MR %) and anomalous Hall resistivity (ρxy) at 10, 100, 200, and 300 K. (b) The variations of magnetization and Hall resistivity normalized to their value at 1 T are plotted as a function of magnetic field. These measurements were performed at 300 K. The absolute value of ρxx and ρxy has an error of ±10% due to the uncertainty in the measurement of film thickness.

    Reuse & Permissions
  • Figure 6
    Figure 6

    The out of plane magnetoresistance and anomalous Hall resistivity of the multilayer at 300 K plotted as a function of magnetic field. The black arrow at the bottom left corner of the figure highlights the cusp in ρxy. The inset shows variation of MR (%) and ρxy at 9 T as function of temperature. The absolute value of ρxx and ρxy has an error of ±10% due to the uncertainty in the measurement of film thickness.

    Reuse & Permissions
  • Figure 7
    Figure 7

    The evolution of the topological Hall resistivity with the magnetic field at several temperatures from 200 to 300 K. The inset shows the ρxy data at 300 K over a limited range of field to highlight the procedure used to extract the data shown in the main figure.

    Reuse & Permissions
×

Sign up to receive regular email alerts from Physical Review B

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×