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Summary: Pinch-Off Maps for the Design of Morphologically Stable
Multilayer Thin Films with Immiscible Phases
Revised June 21, 2005
Jue Wang and Peter M. Anderson
Department of Materials Science and Engineering
Ohio State University
2041 College Road
Columbus, OH 43210-1179
anderson.1@osu.edu
Abstract
Design maps are developed for the time to pinch off via grain boundary grooving in
multilayer thin films consisting of two immiscible phases. Variables include the
(isotropic) interfacial/grain boundary energies, interfacial diffusivities, initial grain aspect
ratio, and imposed in-plane strain rate. The maps are based on a new 2D analysis of
grooving in multilayer thin films that extends earlier work by Thouless [20] for single
phase films. A modified Mullins [11] parameter ~Bmulti and time scale multi are found to
control grooving kinetics, with initial groove depth scaling as t1/4, t3/4, or t, depending on
the magnitude of in-plane strain rate and geometry. The maps predict that nano-scale
films may or may not be more unstable to pinch off at elevated temperature compared to
micro-scale counterparts, depending on morphology, interfacial/grain boundary energies,
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