The epitaxial growth of iron on (111) Au at substrate temperatures of 600–700°C

Abstract

The epitaxial growth of vacuum-deposited iron films on (111) Au crystals was investigated for substrate temperatures in the range 600–700°C. The morphology of the overgrowth indicated that iron grows as b.c.c. needles or paltelets alogned along the <110 > substrate directions. Electron microscopy of prepared specimens revealed that these needles become embedded in the substrate. A model is proposed to explain the process of needle embedment. Defects between the overgrowth and substrate were manifested by rotational moiré fringes and by dislocation images appearing perpendicular and parallel to the sides of the iron needles. Closer analysis shows that dislocations perpendicular to the edges of the needles are edge dislocations with Burgers' vector parallel to ± 1 2 <110 > lyingin the interfacial plane, while dislocations parallel to needle axes are Frank partial dislocations with Burgers' vectors parallel to built:1 3 <111 > . Models for the generation and introduction of the dislocations are presented.