Experimental realization of linearly polarized X-ray detected ferromagnetic resonance

ORAL

Abstract

We present the first theoretical and experimental evidence of time-resolved dynamic X-ray magnetic linear dichroism (XMLD) measurements of GHz magnetic precessions driven by ferromagnetic resonance in both metallic and insulating thin films [1]. Our findings show a dynamic XMLD in both ferromagnetic Ni80Fe20 and ferrimagnetic Ni0.65Zn0.35Al0.8Fe1.2O4 (NZAFO) for different measurement geometries and linear polarizations. A detailed analysis of the observed signals reveals the importance of separating different harmonic components in the dynamic signal in order to identify the XMLD response without the influence of competing contributions. In particular, RF magnetic resonance elicits a large dynamic XMLD response at the fundamental frequency under experimental geometries with oblique x-ray polarization. The geometric range and experimental sensitivity can be improved by isolating the 2ω Fourier component of the dynamic response. To account for the effect of crystal-field splitting on the angular dependence of the spin-quantization axis with respect to the crystalline axes, we include crystal-field contributions in the analysis of the dynamic XMLD spectral lineshapes, which yields excellent agreement with the experimental observations. These results illustrate the potential of dynamic XMLD and represent a milestone accomplishment towards the study of GHz spin dynamics in systems beyond ferromagnetic order.

*This research used resources of the Advanced Light Source, a DOE Office of Science User Facility under contract no. DE-AC02-05CH11231. SE and YS were supported by a Vannevar Bush Faculty Fellowship sponsored by the Basic Research Office of the Assistant Secretary of Defense for Research and Engineering and funded by Office of Naval Research Grant No. N00014-15-1-0045. SE was also supported in part by NSF Grant No. DMR-2003914. ZQ acknowledges financial support by US Department of Energy, Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division under Contract No. DE-AC02-05CH11231 (van der Waals heterostructures program, KCWF16).

–

Presenters

  • Christoph Klewe

    • Lawrence Berkeley National Laboratory
    • Advanced Light Source

Authors

  • Christoph Klewe

    • Lawrence Berkeley National Laboratory
    • Advanced Light Source

  • Satoru Emori

    • Virginia Tech

  • Qian Li

    • University of Science and Technology of China

  • Mengmeng Yang

    • Institute of Physical Science and Information Technology

  • Benjamin A Gray

    • Air Force Research Laboratory, Wright Patterson Air Force Base

  • Hyung Min Jeon

    • Air Force Research Laboratory, Wright-Patterson Air Force Base

  • Brandon Howe

    • Air Force Research Laboratory, Wright-Patterson Air Force Base

  • Yuri Suzuki

    • Stanford University
    • Stanford University, USA

  • Zi Q. Qiu

    • University of California, Berkeley

  • Padraic Shafer

    • Lawrence Berkeley National Laboratory
    • Advanced Light Source

  • Elke Arenholz

    • Pacific Northwest National Laboratory