Scientific Achievement

Nanoscale spin fluctuations are temporally heterogeneous and influence the order-disorder phase transition of chiral spin-textures in thin amorphous FexGe1-x films.

Significance and Impact

Characterizing the growth and magnitude of fluctuations deepens the fundamental understanding of order-disorder transitions in chiral and topological spin phases that are relevant for future spintronic applications.

Research Details

  • Measured diffraction spot size, shape, and intensity with soft X-ray photon correlation spectroscopy (XPCS) as a function of Fe concentration x and temperature T in amorphous Fe-Ge thin films.
  • Small “hot-spots” at lower T indicate small fluctuating regions even in the ordered state.
  • The scaling of fluctuations with magnetization for different x indicates that the phase transition can be described in terms of fluctuations irrespective of the microscopic details.

Publication Details

Singh, E. Hollingworth, S.A. Morley, X.M. Chen, A. Us Saleheen, R. Tumbleson, M.R. McCarter, P. Fischer, F. Hellman, S.D. Kevan, S. Roy, Advanced Functional Materials (2023). DOI: 10.1002/adfm.202300224