The Growth and Crystalline Structure of Ultrathin Mn Films on Ni(111)

Abstract

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 medium‐ and low‐energy electron diffraction. We show that the Mn films deposited at room temperature exhibit a thickness‐dependent growth behavior with a layer‐by‐layer 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 low‐temperature‐deposited wetting layer shows a metastable lattice distortion which vanishes after annealing to room or higher temperatures. This phenomenon may be attributed to a temperature‐dependent metastable arrangement of the Mn adlayer as well as the distinct interaction strength between Mn–Mn and Mn–Ni atoms. Low‐temperature‐grown thick Mn films exhibit a Stranski–Krastanov growth mode with a stable 30° reconstruction, which remains stable up to room temperature.