Nucleation and Growth of Semiconductor-Metallic Superlattices.
Abstract
An investigation of the nucleation and growth as well as magnetic properties of epitaxial FeAl on AlAs/GaAs(100) is reported. These are the first real space studies of the nucleation, growth and properties of so-called thermodynamically stable films. In-situ RHEED and the first UHV STM measurements were used to characterize the surface. Ex-situ MOKE measurements were used to characterize the magnetic properties. FeAl was found to have an unusual incubation effect over the first 3 bilayers of growth on AlAs. STM images taken at 1 and 3 bilayers examined this effect. After depositing 9 nm and annealing, the films exhibited a 2x2 and/or a 5x5 surface reconstruction. This reconstruction depended upon the anneal temperature and film composition. STM images showed atomic step terraces with step heights roughly corresponding to the height of an FeAl bilayer. Differences were also seen in the surface morphology of the 2-fold and 5-fold surfaces. It was determined that the growth mode was primarily dependent upon growth composition, but had some dependence on the annealed FeAl starting surface. The growth mode changed from monolayer to bilayer closely corresponding to the composition at which FeAl changes from ferromagnetic to non magnetic.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 30, 1995
- Accession Number
- ADA311133
Entities
People
- P. I. Cohen
Organizations
- University of Minnesota