alpha-Fe2O3(0001) films of thickness equal to similar to7 nm and similar to70 mn were epitaxially grown on alpha-Al2O3(0001) by oxygen plasma-assisted molecular beam epitaxy. The interfaces were characterized using high resolution transmission electron microscopy, electron energy-loss spectroscopy, and X-ray diffraction. The interface exhibited coherent regions separated by equally-spaced misfit dislocations. When imaged from the [(2) over bar 110] direction, the dislocation spacing is 7.0 +/- 1.1 nm for the 70-nm-thick specimen, and 7.2+/-0.1 nm for the 7-nm-thick specimen. When imaged from the [01 (1) over bar0] direction, the dislocation spacing is 4.5+/-0.1 nm for the 7-nm-thick specimen. The experimentally observed dislocation spacings are approximately consistent with those calculated from the lattice mismatch between alpha-Al2O3 and alpha-Fe2O3, implying that the lattice mismatch is accommodated mainly by interface misfit dislocations above the critical thickness, which is less than 7 run. This conclusion is also corroborated by the measured residual strain of similar to0.5% determined from X-ray diffraction for the 70 mn film. Electron-energy-loss-spectroscopy analysis reveals that the Fe L-2,L-3-edge shows no measurable chemical shift relative to the L-2,L-3-edge of structural Fe+3, indicating complete oxidation of Fe in the as-grown film.