AVS 45th International Symposium
    Magnetic Interfaces and Nanostructures Technical Group Thursday Sessions
       Session MI-ThM

Paper MI-ThM10
Morphology of Mn Films on Fe(001)@footnote 1@

Thursday, November 5, 1998, 11:20 am, Room 324/325

Session: Magnetic Spectroscopies
Presenter: A.D. Davies, National Institute of Standards and Technology
Authors: A.D. Davies, National Institute of Standards and Technology
D.T. Pierce, National Institute of Standards and Technology
J.A. Stroscio, National Institute of Standards and Technology
R.J. Celotta, National Institute of Standards and Technology
Correspondent: Click to Email
Manganese and iron thin film structures have shown promise for studying indirect exchange coupling and for investigating novel magnetic thin film systems. As a function of temperature and stress, Mn has a large variety of structural and magnetic states, so it is particularly important to fully characterize the structure in these films to understand the magnetic behavior. Here we report on scanning tunneling microscopy (STM) measurements of epitaxial Mn films up to ~10 atomic layers grown on Fe(001) at 155 ± 10 °C. The film growth and structure varies dramatically with film thickness and exhibits a range of unusual spatial inhomogeneities. At this growth temperature, the growth is nearly layer-by-layer and shows a decrease with thickness in the island density of ~25 times. Concurrent with this length scale change, the island shape changes from facets along <100> directions to <110> oriented facets. While the atomic-layer height for submonolayer films is difficult to define due to electronic differences, the atomic step height of the second Mn layer is 1.44 ± 0.07 Å and surface step heights of all subsequently thicker films are 1.61 ± 0.03 Å. For films beyond ~2 atomic layers, curious small regions are observed that are a fraction of an atomic step high. The height, shape, frequency, and location of these regions vary with film thickness. The film structure is markedly different in the vicinity of steps on the Fe substrate at almost every coverage. This difference and other observed aspects of the growth suggest that the growth is very sensitive to local stress. @FootnoteText@ @footnote 1@ Supported in part by the Office of Naval Research.