Title :
Magnetic domain evolution in permalloy mesoscopic dots
Author :
Hirohata, A. ; Leung, H.T. ; Xu, Y.B. ; Yao, C.C. ; Lee, W.Y. ; Bland, J.A.C. ; Holmes, S.N.
Author_Institution :
Cavendish Lab., Cambridge Univ., UK
fDate :
9/1/1999 12:00:00 AM
Abstract :
Permalloy (Ni80Fe20) squares (30 nm thick and w μm wide; 1⩽w⩽200 μm) and circular disks (30 nm thick and r μm diameter; 1⩽r⩽200 μm) prepared on a GaAs(100) substrate were observed in both their demagnetized and remanent states by magnetic force microscopy (MFM) associated with non-contact atomic force microscopy (NC-AFM). The squares (2⩽w μm) exhibited conventional closure domains and the corner plays a very important role in creating new walls. The circular disks, on the other hand, formed either vortex domain (5⩽r⩽20 μm) or multi-domain (50⩽r μm) states. The magnetization rotation is observed by MFM to change according to the size and shape of the elements. The MFM observations are supported by micromagnetic calculations which confirm the effect of the corner on the domain wall formation
Keywords :
Permalloy; atomic force microscopy; magnetic domain walls; magnetic force microscopy; magnetisation; mesoscopic systems; quantum dots; 30 nm; GaAs; GaAs(100) substrate; Ni80Fe20; closure domains; demagnetized state; magnetic force microscopy; magnetization rotation; mesoscopic dots; micromagnetic calculations; multi-domain states; noncontact AFM; permalloy; remanent state; vortex domain states; Atomic force microscopy; Demagnetization; Iron; Magnetic domain walls; Magnetic domains; Magnetic force microscopy; Magnetic forces; Magnetization; Micromagnetics; Shape;
Journal_Title :
Magnetics, IEEE Transactions on
