Analysis of the etching behavior of ZnO ceramics

ZnO ceramics doped with a small amount of Bi2O3 and Sb2O3 were prepared and their orientation-dependent etching patterns were analyzed. Three distinctive patterns produced by the oxidizing etchant HCl were observed: hexagonal etch pits on +C plane, triangular etch pits on prismatic plane, and hillocks of hexagonal pyramid on −C plane. From these results, the three-dimensional shape of etch pit could be suggested. The character of inversion boundary was also determined from the etching patterns.