Published online by Cambridge University Press: 21 February 2011
We have investigated the growth mode of iron on clean Cu(100), Cu (110) and Cu(111) surfaces using high resolution LEED. We studied the effect of substrate temperature on the growth of epitaxial fee iron. Iron metal was evaporated from an electron beam source under UHV conditions and deposited on the copper single crystal surfaces at three different temperatures (173 K, 300 K and 473 K). A high resolution LEED system was used to measure the diffraction spot profiles. The samples were studied as a function of temperature after deposition on the copper substrates. The clean Cu surfaces were also measured and used as references for the Fe:Cu system. The diffraction spot profiles show Gaussian line shape before and after the Fe deposition. The effect of iron grown on the Cu surface is to reduce the coherent length. This effect is observed for all the copper surfaces. The intensity of the diffraction spots exhibit a sudden increase above 470 K, simultaneously a larger coherent length is observed. This effect occurs for all copper surfaces. The epitaxial growth of Fe is better on Cu (100) than on the other surfaces. The best epitaxial growth is obtained for the highest substrate temperature. A careful Auger study reveals that the anomalous increase observed on the intensity of the diffraction spots is related to the evaporation of iron from the copper surface. The spot profiles at low temperature are very broad and are suggestive of very poor epitaxy, random islands growth with a high probability of bec iron inclusions.