Effect of co-doping on proton conductivity in perovskite oxides BaZr0.9In0.05M0.05O3−δ (M = Yb3+ or Ga3+)

Journal article, 2010

BaZr0.9In0.05M0.05O3-d (M ¼ Ga3+ or Yb3+) has been prepared by solid-statesynthesis route. Rietveld analysis of neutron powder diffraction data on as-prepared samples showed that both samples crystallise in the cubic space group Pm-3m. Scanning electron microscopy analysis showed that the grains intheBaZr0.9In0.05Ga0.05O3-d sample were larger than the BaZr0.9In0.05Yb0.05O3-d sample. Dynamic thermogravimetric analysis indicates that the proton concentration was higher inpre-hydrated BaZr0.9In0.05Ga0.05O3-d sample (40%of theoretical)than that of BaZr0.9In0.05Yb0.05O3-d sample (28%oftheoretical).Proton conductivity was studied on pre-hydrated samples(under both dry and wetAr atmospheres).The bulk proton conductivities of the heating cycle of pre-hydrated BaZr0.9In0.05M0.05O3-d (M ¼ Ga3+ or Yb3+) samples were 2.1 * 10-5 S cm-1 and 1.9 * 10-4 S cm-1 at 350C, respectively.The effect of co-doping onproton conductivity was investigated and the results are compared with single doped systems e.g. BaZr0.9M0.1O3-d (M=Ga3+, In3+ or Yb3+) samples.