High-pressure phase transformation of silicon nitride
Contributors: John Patten, Ronnie Fesperman, Satya Kumar, Sam McSpadden, Jun Qu, Michael Lance, Robert J. Nemanich, and Jennifer Huening
ABSTRACT
We provide evidence for a high-pressure phase transformation (HPPT) in the ceramic material silicon nitride. This HPPT is inferred by a high-pressure diamond anvil cell, Raman spectroscopy, scanning/transmission electron microscopy, and optical and acoustic microscope inspection. In the case of silicon nitride, the HPPT involves a ductile or metallike behavior that is observed in severe deformation processes, such as nanoindentation and micromachining. This pressure-induced plasticity is believed to be similar to that found in silicon and germanium with its origin in the high-pressure metallic β-Sn phase formation.