Densification and grain growth of SrO-doped ZnO

Abstract

The grain growth kinetics in the 1, 2, 3 and 4 wt.% SrO doped ZnO was studied using the simplified phenomenological grain growth kinetics equation G(n) - G(0)(n) = K-0 t exp(-Q/RT) together with microstructure properties and densification of the sintered samples. The grain growth exponent values (n) were found to be 5 for 1, 2, 3 and 4 wt.% SrO doped ZnO. The apparent activation energies for 1, 2, 3 and 4 wt.% SrO doped ZnO were found 780 kJ/mol, 709 kJ/mol, 764 kJ/mol and 744 kJ/mol, respectively. The apparent activation energy was increased with doping of SrO because of ZnSrO2 phase at the grain boundaries. This ZnSrO2 phase inhibited the grain growth of ZnO. But the increasing SrO level had no effect on the grain growth. Also, the increasing of SrO resulted in a slight reduction in densification at all temperatures.