Study on microstructure and dielectric properties of aluminum nitride ceramics

Aluminum nitride (AlN) ceramics were prepared by spark plasma sintering (SPS) technique. Purifying effect of sintering additive, dielectric properties, and polarization mechanism of AlN ceramics were investigated. Secondary phases, oxygen impurities, defects and the amorphous layer et al. increase the dielectric loss. The space charge polarization might be the main polarization mechanism of AlN ceramics.111