The Grain Growth Kinetics of 0.5 mol% B2O3-1 mol% TiO2-doped ZnO Ceramics

Abstract

The influence of the 0.5 mol% B2O3 addition on the grain growth of ZnO-1 mol% TiO2 ceramics was studied. The samples were sintered at 1100-1300 degrees C for 1, 2 and 3 hours. The bulk density of samples was calculated from their mass/volume ratio. The additions of TiO2 and B2O3 enhanced significantly the densification of ZnO. The Zn2TiO4 phase was identified by the XRD analysis in the 1 mol% TiO2 doped ZnO samples sintered at 1100 degrees C for 1 hour. Grain size measurements were carried out on the optical micrographs of polished and etched samples using the following equation; G = 1.56 L where G is the average grain size, L is the average grain boundary intercept length of a series of random lines on the micrographs. The apparent activation energy for the grain growth process of un-doped ZnO was 210 kJ/mol and this value decreased to 162 kJ/mol with the addition of 1 mol% TiO2. Furthermore, the addition of 0.5 mol% B2O3 to the 1 mol% TiO2-doped ZnO samples promoted the grain growth and the apparent activation energy decreased to 124 kJ/mol.