Browsing by Author "Fujiwara, H."

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Strong uniaxial magnetic anisotropy in CoFe films on obliquely sputtered Ru underlayer
    (American Institute of Physics, 2009-10-02) Fukuma, Y.; Lu, Z.; Fujiwara, H.; Mankey, G. J.; Butler, W. H.; Matsunuma, S.; University of Alabama Tuscaloosa; Hitachi Limited
    Co(90)Fe(10) films with an in-plane uniaxial magnetic anisotropy have been grown on an obliquely sputtered thin Ru underlayer. The anisotropy field can be increased up to 200 Oe. The hysteresis curves show a very high squareness in the easy axis direction and almost no hysteresis in the hard axis direction, suggesting that the induced uniaxial anisotropy is uniform throughout the films. The switching characteristics of the nanoelements fabricated from the films by e-beam lithography are also investigated. There is no degradation of the magnetic anisotropy after the annealing and lithographical process. (C) 2009 American Institute of Physics. [doi:10.1063/1.3223538]
  • Thumbnail Image
    Item
    Trimmed-diamond shaped toggle magnetoresistive random access memory cells
    (American Institute of Physics, 2009-04-08) Fukuma, Y.; Fujiwara, H.; Visscher, P. B.; Mankey, G. J.; University of Alabama Tuscaloosa
    We have performed micromagnetic simulations for the design of toggle magnetoresistive random access memory (MRAM) cells to make the operating field as low as possible while keeping a reasonable margin and thermal stability. The memory cells are composed of weakly coupled synthetic antiferromagnets. The cells are diamond-shaped to suppress the formation of edge domains, which increase the operating field. The adverse effect of the diamond shape making the remanent state too stable is prevented by trimming the sharp points. The optimization of the trimming allows us to reduce the operating field and offer a pathway for realizing high-density toggle MRAM. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3104788]