GRAIN-BOUNDARY SEM CONDUCTIVE MODE CONTRAST EFFECTS IN ADDITIVE FREE ZINC-OXIDE CERAMICS

Conductive mode imaging of sintered zinc oxide has been carried out in the SEM using the remote electron beam induced current mode. The use of this technique enables the electrical effects of built-in fields an d resistive barriers in the material to be imaged in the microstructur e. Two contrast types were observed at grain boundaries where such fie lds or barriers were active; parallel bright and dark lines, or single bright/dark lines. Possible structures giving rise to these contrast effects are discussed.