THE EFFECT OF ELECTRON-IRRADIATION ON RUTILE CRYSTALS

A combination of electron microscopy techniques including HREM, STEM, SEM and EELS has been used to study the consequences of intense electron irradiation on the surfaces and bulk of crystalline rutile. Under extreme TEM imaging conditions (10 approximately 100 A/cm2), clean surfaces are reduced to the monoxide phase as identified by lattice fringe measurements. With moderate irradiation in the STEM (approximately 250 A/cm2), secondary electron images from the entrance and exit surfaces indicate that, even at 100 keV, sputtering is occuring from the exit surface. Different effects are observed in the STEM when an intense focussed probe is used.