Periodicity staircase in a Fe/Gd magnetic thin film

Abstract

Presence of multiple competing periodicities may result in a system to go through states with modulated periodicities, an example of which is the self-similar staircase-like structure called the Devil's staircase. Herein we report on a novel staircase structure of domain periodicity in an amorphous and achiral Fe/Gd magnetic thin film wherein the reciprocal space wavevector \textbf{Q} due to the ordered stripe domains does not evolve continuously, rather exhibits a staircase structure. Resonant X-ray scattering experiments show jumps in the periodicity of the stripe domains as a function of an external magnetic field. When resolved in components, the step change along Q${}_x$ was found to be an integral multiple of a minimum step height of 7 nm, which resembles closely to the exchange length of the system. Modeling the magnetic texture in the Fe/Gd thin film as an achiral spin arrangement, we have been able to reproduce the steps in the magnetization using a Landau-Lifshitz spin dynamics calculation. Our results indicate that anisotropy and not the dipolar interaction is the dominant cause for the staircase pattern, thereby revealing the effect of achiral magnetism.

10 pages, 5 figures

References in corpus (5)

• Tailoring magnetic energies to form dipole skyrmions and skyrmion lattices
• Theory of helical spin crystals: phases, textures and properties
• Devil's staircase transition of the electronic structures in CeSb
• Generic character of charge and spin density waves in superconducting cuprates
• Observation of Devil's Staircase in the Novel Spin Valve System SrCo${}_6$O${}_{11}$