Effects of Frit Addition on the Surface Morphology and Structural Properties of ZnO-Bi_2O_3-Mn_2O_3 Discs

摘要

ZnO-Bi_2O_3-Mn_2O_3 discs were prepared using conventional ceramic processing method and sintered at 1000°C. The different percentages of frit on the ZnO-Bi_2O_3-Mn_2O_3 discs were 0.0%, 0.5%, 1.0% and 3.0%. From FESEM observation, the grain structure and grain growth were more uniformly constructed and well distributed. Frit addition was found to cause a big drop in the average grain size from 4.59 μm to 2.76 μm even with an addition of 0.5 mol%. The Si and Al content in the frit recipe might have played a role as inhibiting agents in grain growth during sintering. RAMAN intensity and phase shifting were not affected by frit addition except at 3 mol%. Frit addition did not affect the formation of secondary phases. Frit addition below 3 mol% in ZnO-Bi_2O_3-Mn_2O_3 varistor discs can be used as a method in controlling grain size without affecting other properties.