Published online by Cambridge University Press: 21 February 2011
The grain boundary phase of silicon nitride containing additives Y2O3 and Nd2O3 has been studied by means of a newly developed 300kV field emission ATEM. The composition of the two-grain boundary phase of about 1 nm thick is successfully determined. It is then found that the compositions among the grain boundaries are not the same and the additives of Y2O3-Nd2O3 are poor in the two-grain boundary, while they are rich in the triple points.