Grain Growth of Zinc Oxide During the Sintering of Zinc Oxide—Antimony Oxide Ceramics

Grain growth in a high‐purity ZnO with systematic additions of Sb 2 O 3 from 0.29 to 2.38 wt% was studied for sintering in air from 1106° to 1400°C. The results are discussed and compared with previous studies of pure ZnO and ZnO with Bi 2 O 3 additions in terms of the kinetic grain growth expression: G n – G n 0 = K 0 t exp(— Q/RT ). Additions of Sb 2 O 3 inhibited the grain growth of ZnO and increased the grain growth exponent ( n ‐value) to 6 from 3 for pure ZnO and 5 for the ZnO—Bi 2 O 3 ceramic. The apparent activation energy for the grain growth of ZnO also increased to about 600 kJ/mol from 220 kJ/mol for pure ZnO and 150 kJ/mol for the ZnO—Bi 2 O 3 ceramics. Both the grain growth exponent and the activation energy were independent of the Sb 2 O 3 content. Particles of the Zn 7 Sb 2 O 12 spinel were observed on the grain boundaries and at the grain triple point junctions. It was also observed that the Sb 2 O 3 additions caused twin formation in each ZnO grain. It is concluded that both the Zn 7 Sb 2 O 12 particles and the twins are responsible for the ZnO grain growth inhibition by Sb 2 O 3 .