Quantum Electronic Stability of Atomically Uniform Films
D.-A. Luh,12
T. Miller,12
J. J. Paggel,3
M.
Y. Chou,4
T.-C. Chiang12*
We have studied the structural stability of thin silver
films with thicknesses of N = 1 to 15 monolayers,
deposited on an Fe(100) substrate. Photoemission spectroscopy results
show that films of N = 1, 2, and 5 monolayer
thicknesses are structurally stable for temperatures above 800 kelvin,
whereas films of other thicknesses are unstable and bifurcate into a
film with N ± 1 monolayer thicknesses at temperatures
around 400 kelvin. The results are in agreement with theoretical
predictions that consider the electronic energy of the quantum well
associated with a particular film thickness as a significant
contribution to the film stability.
1 Department of Physics, University of Illinois
at Urbana-Champaign, 1110 West Green Street, Urbana, IL 61801-3080,
USA.
2 Frederick Seitz Materials Research
Laboratory, University of Illinois at Urbana-Champaign, 104 South
Goodwin Avenue, Urbana, IL 61801-2902, USA.
3 Freie
Universität Berlin, Institut für Experimentalphysik, 14195 Berlin, Germany.
4 School of Physics, Georgia
Institute of Technology, Atlanta, GA 30332-0430, USA.
*
To whom correspondence should be addressed. E-mail:
chiang{at}mrl.uiuc.edu
