Impurity Distribution in Polycrystalline Aluminum Nitride Ceramics

Abstract

Convergent‐beam electron diffraction and diffuse darkfield imaging of transmission electron microscopy were used to obtain qualitative information regarding the distribution of impurities in polycrystalline AIN. Impurities are distributed homogeneously within the grains of a given ceramic, but an amorphous grain‐boundary phase on the order of 1 to 2 nm in thickness is observed between the AIN matrix grains.