AVS 47th International Symposium
    Surface Science Wednesday Sessions
       Session SS3-WeA

Paper SS3-WeA3
Oriented Quantum Dots By Buffer Layer Growth Process

Wednesday, October 4, 2000, 2:40 pm, Room 210

Session: Surface and Interface Structure I
Presenter: A.P. Baddorf, Oak Ridge National Laboratory
Authors: A.P. Baddorf, Oak Ridge National Laboratory
J.F. Wendelken, Oak Ridge National Laboratory
C.T. Venkataraman, Argonne National Laboratory
T. Gog, Argonne National Laboratory
Correspondent: Click to Email
Quantum dots of Fe formed by a multi-step growth process are shown to be highly oriented on a Cu(100) substrate. Growth involved deposition of Fe on a buffer of 200 layers of condensed Xe. The Xe buffer layer, which promotes clustering, was subseque ntly removed by heating. In situ scanning tunneling microscopy results reveal formation of 3-D Fe clusters averaging 10 nm in diameter. An additional 20 nm thick cap of Cu was deposited over the Fe to allow ex situ x-ray studies at the Advanc ed Photon Source. Fe clusters were found to be highly oriented, with the close-packed [110] direction normal to the Cu(100) surface and with two in-plane orientations. The first in-plane structure has Fe \{-112\} planes aligned with Cu \{001\} and the se cond has Fe \{-110\} planes aligned with Cu \{001\}. These orientations are not observed in molecular beam epitaxy of Fe directly onto Cu(100) or in precipitate growth. Buffer layer growth bypasses the intermediate fcc Fe phase formed by direct deposition on fcc Cu and brings bcc Fe immediately into contact with fcc Cu. Sidestepping the fcc Fe phase may allow the newly observed orientations.@footnote 1@ @FootnoteText@ @footnote 1@ORNL is managed by UT-Battelle, LLC, under US DOE contract DE-AC05-00OR22725. The APS is supported by US DOE contract W-31-109-Eng-38.