Shape dependent magnetization reversal processes of microstructured epitaxial Fe[110] elements

Summary form only given. The magnetization reversal processes and magnetic domain states of microstructured epitaxial Fe[110] elements have been investigated by magnetic force microscopy and longitudinal Kerr hysteresis loop measurements. For this purpose 25 nm thick epitaxial Fe[110] films were grown on (11-20) oriented Al/sub 2/O/sub 3/ substrates using molecular beam epitaxy techniques in ultra high vacuum. These films have been patterned into arrays of well defined magnetic elements with lateral dimensions of 1.5 /spl mu/m/spl times/0.5 /spl mu/m by electron beam lithography followed by argon ion milling. Two different particle shapes have been realized: rectangular and diamond- shaped elements. By aligning the long axis of the particles parallel to the easy magnetic axis of the Fe[110] films, i.e. the in-plane Fe[001] direction, the interplay of shape, magnetocrystalline, as well as the strain-induced uniaxial anisotropy favors a single domain state. It has been shown that the characteristic micromagnetic behavior such as coercive and nucleation fields can be tailored by taking advantage of the pronounced uniaxial anisotropy and by varying the shape of the elements. Independent of the shape of the elements the remanent state after magnetic saturation along the long axis of the elements is a single domain state. In contrast, after magnetic saturation perpendicular to the long axis various multi-domain states have been observed. The determined flux closure domain states are in good agreement with micromagnetic simulations.