Magnetic reversal of ultrathin films with planar magnetization

Physical Review B - Condensed Matter and Materials Physics

Volumn 60, Issue 21, 1999, Pages 14830-14836

  Stiles, M D ^b   Zangwill, A ^a  

^a GEORGIA INSTITUTE OF TECHNOLOGY   (United States)

^b NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0000553384     PISSN: 10980121     EISSN: 1550235X     Source Type: Journal    
DOI: 10.1103/PhysRevB.60.14830     Document Type: Article

References (29)

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23. The fields here called (Formula presented) and (Formula presented) were called (Formula presented) and (Formula presented) in Refs. 14 and 15.The notation in this paper is the same as Ref. 16.
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25. The phases labeled III and IV in Ref. 16 should now be called IIIc and IVc.
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27. We have generalized a fast Fourier transform (FFT) technique used for flat films [see, e.g., by M. Mansuripur, The Physical Principles of Magneto-optical Recording (Cambridge University Press, Cambridge, 1995), Sec. 13.2] to the case of rough films. By construction, the magnetization is uniform within each spin block. The magnetostatic energy contains an intrablock term and an interblock term. The intrablock energy accounts for the shape anisotropy of the block. This part of the magnetostatic energy is functionally identical to a bulk crystalline anisotropy that favors in-plane spins. Surface roughness is easily incorporated in this term because it is local and explicitly linear in the thickness. A 2D FFT magnetostatic routine is used to calculate the interblock magnetostatic energy. The routine has been derived for uniformly flat films. However, surface roughness can still be incorporated. To lowest order in the thickness, the interblock energy is dependent only on the magnetic moments of the blocks. Therefore, surface roughness is included by performing the FFT on an effective flat film in which the magnetization magnitude is adjusted so that the block magnetic moments of the two films are identical. The magnetization in the effective film is (Formula presented) per site, chosen so that the block magnetic moments of the flat and rough films are identical.
28. B. Heinrich and J. F. Cochran, Adv. Phys. 42, 523 (1993).These are the values used in Refs. 1415. The size of the fourfold anisotropy was misstated there as (Formula presented)
29. The magnetization pattern at nucleation discussed here is unstable if a jump in magnetization accompanies nucleation. But this pattern is still used to determine the energy barrier to nucleation.See Ref. 16 for more details.