Compressively-stressed elastic films on finite-thickness viscous substrates
can undergo a buckling instability that relieves stresses but destroys the
planarity of the film. A linear-stability analysis is performed to determi
ne the onset and maximally unstable mode of this buckling instability as a
function of misfit strain, viscous layer thickness, and viscosity. We find
that the onset of the buckling instability of the film on a glass layer is
the same as that for a compressively stressed free-standing film. However,
the maximally unstable wavelength increases as the glass layer thickness in
creases. Comparisons with experimental data are provided. (C) 2001 American
Institute of Physics.