Spontaneous Ordering of Oxide Nanostructures
S. Aggarwal,
1*
A. P. Monga,
1
S. R. Perusse,
1
R. Ramesh,
1
V. Ballarotto,
2
E. D. Williams,
2
B. R. Chalamala,
3
Y. Wei,
3
R. H. Reuss
3
We report the spontaneous formation of uniformly distributed arrays
of "tips" (tall conical hillocks) upon oxidation of palladium (Pd)
thin films. The formation of the palladium oxide tips depended on the
thickness and granularity of the Pd film and on annealing and oxidation
conditions. As the Pd film thickness increased from 40 to 200 nanometers, the average height of the tips increased from 0.5 to 1.2 micrometers, their height distribution became broader, and their
density decreased from 55 × 106 to 12 × 106 per square centimeter. Enhanced photoelectron emission
from locations corresponding to the tips suggests their possible use in
field emission applications.
1 Department of Materials and Nuclear
Engineering,
2 Department of Physics, University of
Maryland, College Park, MD 20742, USA.
3 Flat Panel
Display Division, Motorola Inc., 7700 South River Parkway, Tempe, AZ
85284, USA.
*
To whom correspondence should be addressed. E-mail:
aggarwal{at}eng.umd.edu
