Characterization of room-temperature plastic deformation Of beta-Si3N4 by atomic force microscopy and transmission electron microscopy

Dislocation microstructures induced by room-temperature microhardness tests have been investigated in silicon nitride. Surface analysis of the residua l indent by atomic force microscopy reveals intragranular slip bands and de monstrates that room-temperature plastic deformation involves dislocation m otion as well as cross-slip events. Cross-slip events have been found to oc cur between (10(1) over bar 0) prismatic planes. Transmission electron micr oscopy shows that dislocations have a Burgers vector b = [0001] and are loc ated along the screw direction. Based on these observations, specific dislo cation core configurations are discussed.