| Abstract Scope |
The nanochessboard is a fascinating microstructure in which to investigate exchange-coupled ferromagnetism. In Co-Pt, cooling through the eutectoid, A1 → L10+L12 , produces a quasi-periodic tiling of L10 nanorods coherently embedded in an L12 matrix. Both ordered product phases are ferromagnetic, where L10 (L12) has large (small) magnetocrystalline anisotropy. First order reversal curve analysis shows that exchange-coupling evolves from partial to complete as the period is reduced to the critical lengthscale. The Fe-Pt system offers distinct advantages, since there will be higher magnetic moment in the soft phase and larger anisotropy in the hard phase, vis-à-vis Co-Pt. However, the chessboard has not been previously observed in this system, and we will show initial results on eutectoid decomposition in the two-phase region. Micromagnetic simulations are also being carried out to examine the effects of increased magnetization and magnetocrystalline anisotropy. Support of the National Science Foundation through grant DMR-1709914 is gratefully acknowledged. |