Effect of CuO on the Sintering Behavior, Microstructure and Proton Conductivity of Yttrium Doped Barium Zirconate

In the present work, the effect of addition of 2 wt% CuO on the sintering behavior, microstructure and proton conductivity of the yttrium doped barium zirconate has been studied. Yttrium doped barium zirconate (BZY20) including 2 wt% CuO, as sintering aid, was produced via solid state synthesis method using carbonate and oxides as raw materials. To characterize the crystal structure of the synthesized compounds, XRD analysis was used. The green samples, produced by dry pressing, were sintered in the range of 1300 to 1500 oC for 5 to 24 h. Microstructure of the sintered samples was studied by the means of SEM to determine the amount of remained porosities and the grain sizes. Proton conductivity of the samples was determined using impedance analyzer in a wet and dry reducing atmosphere. The results showed that using 2 wt% CuO is so effective in reducing the sintering temperature and also in increasing the size of the grains. So that the sintering temperature decreased to 1400 oC and grain size increased to more than 5 times. These results also showed that in the presence of 2 wt% CuO the conductivity of the BZY20 compounds can be improved.