Sintering time dependence of microwave dielectric properties and crystal structure in Y2BaZnO5 ceramic

The effect of sintering time on the microwave dielectric properties and crystal structure of the Y2BaZnO5 ceramic was investigated in this study. The Y2BaZnO5 ceramic was sintered at 1300 °C for 2–100 h in air; the significant variations in the dielectric constant and the temperature coefficient of resonant frequency of the Y2BaZnO5 ceramic were not observed with the variations in the sintering time. Although the quality factor of the samples increased from 50,000 to 189,000 GHz with increasing the sintering times from 2 to 50 h, a decrease in the quality factor was recognized when the sample was sintered for 100 h at the temperature of 1300 °C. By refining the site occupancy of Zn in terms of the Rietveld analysis, it was found that the vaporization of Zn in amounts was at least 0.05 mol in the case of the Y2BaZnO5 compound sintered for 100 h. Thus, the marked degradation of the quality factor of the sample sintered for 100 h is related to the vaporization of Zn, which depends on the variations in the sintering time.