We have performed a detailed study on thermal annealing of the moment configuration in artificial spin ice. Permalloy (Ni80Fe20) artificial spin ice samples were examined in the prototypical square ice geometry, studying annealing as a function of island thickness, island shape, and annealing temperature and duration. We also measured the Curie temperature as a function of film thickness, finding that thickness has a strong effect on the Curie temperature in regimes of relevance to many studies of the dynamics of artificial spin ice systems. Increasing the interaction energy between island moments and reducing the energy barrier to flipping the island moments allow the system to more closely approach the collective low energy state of the moments upon annealing, suggesting new channels for understanding the thermalization processes in these important model systems.
Bibliographical noteFunding Information:
Work at the University of Illinois at Urbana-Champaign and Yale University was funded by the US Department of Energy, Office of Basic Energy Sciences, Materials Sciences and Engineering Division under Grant No. DE-SC0010778. This work was carried out in part in the Frederick Seitz Materials Research Laboratory Central Research Facilities, University of Illinois at Urbana-Champaign. Work at the University of Minnesota was supported by NSF through Grant No. DMR-1807124. The work of C.N. was carried out under the auspices of the US DoE through LANL, operated by Triad National Security, LLC (Contract No. 892333218NCA000001) and financed by DoE LDRD.
© 2019 Author(s).