Dear listers

I thought this article was worth sharing. It came out in the 4 March issue of
Applied Physics Letters from UC Berkeley and LBNL.

Title: "Mechanism of fatigue in micron-scale films of polycrystalline silicon
for microelectromechanical systems"
Authors: C.L. Muhlstein, E.A. Stach, R.O. Ritchie
Abstract:
Reported nearly a decade ago, cyclic fatigue failure in silicon thin films has
remained a mystery. Silicon does not display the room-temperature plasticity or
extrinsic toughening mechanisms necessary to cause fatigue in either ductile
(e.g., metals) or brittle (e.g., ceramics and ordered intermetallics) materials.
This letter presents experimental evidence for the cyclic fatigue of silicon via
a conceptually different mechanism termed reaction-layer fatigue. Based on
mechanical testing, electron microscopy, and self-assembled monolayers, we
present direct observation of fatigue-crack initiation in polycrystalline
silicon, the mechanism of crack initiation, and a method for altering fatigue
damage accumulation.
Reference: Applied Physics Letters (2000) 80, 15321534


--
Christopher F. Blanford
Inorganic Chemistry Laboratory, South Parks Road, Oxford, OX1 3QR, UK
Phone: (44)/(0)-1865-282603; Fax: (44)/(0)-1865-272690
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