Domain structures in epitaxial (110) Fe3O4 particles studied by magnetic force microscopy

Magnetic domain structures on single-crystalline magnetite (Fe3O4) particles, prepared by microfabrication techniques from molecular-beam epitaxial (110) magnetite films grown on MgO, were studied by magnetic force microscopy. The (110) magnetite film thickness was 250 nm and the patterned particles ranged in size from 2×2 to 10×10 μm. The patterned particles showed in-plane, stripe-like domain structures with ill-defined and fragmented walls mainly aligned along the in-plane [110] direction. In both the parent film and the patterned particles, an out-of-plane component of the stray field was observed within domain interiors as a fine-scale (100–300 nm) and spatially variable magnetic contrast present in both the remanent state and in applied fields. Individual wall sections were observed to be highly fragmented with variable widths (100–300 nm) and offsets and subdivided into opposite polarity segments of variable lengths. Remagnetization of a 10×10 μm particle in fields up to 500 Oe occurred by reverse ...