Issue
EPL
Volume 86, Number 1, April 2009
Article Number 16001
Number of page(s) 6
Section Condensed Matter: Structural, Mechanical and Thermal Properties
DOI http://dx.doi.org/10.1209/0295-5075/86/16001
Published online 14 April 2009
EPL, 86 (2009) 16001
DOI: 10.1209/0295-5075/86/16001

Strain effect on the instability of island formation in submonolayer heteroepitaxy

Maozhi Li1, Yugui Yao2, Biao Wu2, Zhenyu Zhang3, 4 and Enge Wang2

1   Department of Physics, Renmin University of China - Beijing 100872, China
2   Institute of Physics, Chinese Academy of Sciences - P.O. Box 603, Beijing 100190, China
3   Materials Science and Technology Division, Oak Ridge National Laboratory - Oak Ridge, TN 37831, USA
4   Department of Physics and Astronomy, The University of Tennessee - Knoxville, TN 37996, USA

maozhili@ruc.edu.cn
ygyao@aphy.iphy.ac.cn

received 10 November 2008; accepted in final form 9 March 2009; published April 2009
published online 14 April 2009

Abstract
A theoretical model is developed to study the strain effect on the instability of island formation in submonolayer heteroepitaxy in both thermodynamic and growth kinetic regimes. By using the linear-stability analysis, the elastic energy change of a circular island is derived. Combined with a rate equation theory, the interplay between growth kinetics and strain effect on the shape instability is analyzed and illustrated with the constructed morphological phase diagrams. Critical island sizes beyond which islands grow unstable are also derived and can be used to estimate the energy parameters. Well-defined scaling properties are also obtained for the shape instability.

PACS
68.35.Gy - Mechanical properties; surface strains.
81.15.Aa - Theory and models of film growth.
68.35.Md - Surface thermodynamics, surface energies.

© EPLA 2009