281 research outputs found
The Growth and Crystalline Structure of Ultrathin Mn Films on Ni(111)
The growth and crystalline structure of ultrathin Mn films are studied in terms of thickness and temperature by scanning tunneling microscopy (STM) as well as mediumâ and lowâenergy electron diffraction. We show that the Mn films deposited at room temperature exhibit a thicknessâdependent growth behavior with a layerâbyâlayer growth mode up to 5.3 monolayers. Two transitions in the growth mode can be observed in this range. Atomically resolved STM images of a submonolayer of Mn on Ni(111) reveal a lateral lattice distortion which becomes less significant after the islands form a wetting layer at room temperature. The lowâtemperatureâdeposited wetting layer shows a metastable lattice distortion which vanishes after annealing to room or higher temperatures. This phenomenon may be attributed to a temperatureâdependent metastable arrangement of the Mn adlayer as well as the distinct interaction strength between MnâMn and MnâNi atoms. Lowâtemperatureâgrown thick Mn films exhibit a StranskiâKrastanov growth mode with a stable (sqrt(3) x sqrt (3))R 30° reconstruction, which remains stable up to room temperature
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