Growth morphology of epitaxial Fe films on annealed MgO [001] surfaces

摘要

The effects of substrate annealing on the growth morphology of bcc-Fe[001] films epitaxially grown on MgO [001] surfaces have been investigated. Substrate annealing at 1000/spl deg/C for 30 minutes produced step-terrace surfaces which are the basis of flat and square Fe islands. By increasing the annealing time, the step profiles are improved to form long straight steps. Longer annealing time caused an increase of segregated impurities regions and a reconstruction of the MgO surface. The presence of the segregated impurities and the reconstructed MgO surface negate the annealing effects, i.e. it reduces the step edge growth that enhances the formation of round islands, degrades the uniformity of Fe island size and increases the rms roughness of Fe films.