Dissolution Behavior of Al and Formation Process of ZnAl2O4Phases in Al2O3-Doped ZnO Sintered Bodies

Al-doped ZnO sintered bodies, which were doped with 0–2 mol % Al 2 O 3 , were prepared from a powder mixture. Al could dissolve in ZnO grains uniformly and a fraction of Al tended to segregate along ZnO grain boundaries when the Al concentration was low. The decrease in the [ c / a ] lattice ratio suggested that the solubility of Al in ZnO increased with increasing concentration of Al 2 O 3 . The solubility of Al reached the limit when Al 2 O 3 was doped at more than 1 mol %. ZnAl 2 O 4 particles appeared before the solubility of Al reached the limit, indicating that the dissolution of Al and the formation of ZnAl 2 O 4 phases occurred simultaneously in the Al 2 O 3 –ZnO sintering process.