  We report on self-assembled iron oxide nanoparticle films on silicon
substrates. In addition to homogeneously assembled layers, we fabricated
patterned trenches of 40-1000 nm width using electron beam lithography for the
investigation of assisted self-assembly. The nanoparticles with a diameter of
20 nm +/- 7% were synthesized by thermal decomposition of iron oleate complexes
in trioctylamine in presence of oleic acid. Samples with different track widths
and nanoparticle concentration were characterized by scanning electron
microscopy and by superconducting quantum interference device magnetometry.
