AVS 50th International Symposium
    Surface Science Thursday Sessions
       Session SS3-ThM

Paper SS3-ThM11
Initial Stages of Cu@sub 2@O Nano-Clusters Formation on SrTiO@sub 3@(100)@footnote 1@

Thursday, November 6, 2003, 11:40 am, Room 328

Session: Oxide Structure, Growth, and Defects
Presenter: I. Lyubinetsky, Pacific Northwest National Laboratory
Authors: I. Lyubinetsky, Pacific Northwest National Laboratory
S. Thevuthasan, Pacific Northwest National Laboratory
A.S. Lea, Pacific Northwest National Laboratory
D.E. McCready, Pacific Northwest National Laboratory
D.R. Baer, Pacific Northwest National Laboratory
Correspondent: Click to Email
Self-assembled crystalline cuprous oxide (Cu@sub 2@O) nano-clusters have been grown on the SrTiO@sub 3@(100) substrate using oxygen plasma assisted molecular beam epitaxy. The growth mechanism, composition and structure were examined by x-ray photoelectron spectroscopy, x-ray induced Auger electron spectroscopy, scanning probe microscopy, scanning Auger microscopy, and x-ray diffraction. Growth parameters for the formation of pure Cu@sub 2@O nano-clusters have been optimized accordingly to the surface phase diagram of the Cu-O system, which has been determined for temperature versus oxygen pressure. Unlike typical semiconductor systems, e.g. Si-Ge, initial stages of the growth for studied here metal oxide system proceed without formation of the wetting layer, with formation of the 3D truncated square Cu@sub 2@O dots starting already at sub-monolayer coverages. At following stages of the growth, nano-dots underwent shape/structure transformation similar to the semiconductor systems. Under different surface conditions of the SrTiO@sub 3@(100) substrate (high temperature annealed, perfect TiO@sub 2@-terminated surface vs. original mixed-terminated surface) significant differences in the uniformity of the nano-clusters distribution have been observed. Complications due to the re-growth of the Sr-rich nanostructures in addition to the Cu@sub 2@O nano-dots formation at the certain substrate conditions will be also discussed. @FootnoteText@ @footnote 1@ This work has been conducted as part of the PNNL Nanoscience and Nanotechnology Initiative supported by the U. S. Department of Energy.