First-Principles Study of Protonic Conduction in Acceptor-Doped SrZrO₃

抄録

To account for the doping effects on the protonic conductivity of perovskite-type oxides, the optimized geometries, formation energies of hydrogen defect and activation energies for hydrogen diffusion in SrZrO₃ doped with Al, Sc, Ga, Y, Rh, In, Yb were calculated using the density functional theory (DFT) under the generalized gradient approximation (GGA). It was shown that large local distortion was induced around hydrogen and dopant ion, and affected the activation energy greatly. There is good agreement between the measured and calculated activation energies. The hydrogen diffusion seems to become more difficult as the distance between hydrogen and dopant ion decreases. Also, the calculated formation energy of hydrogen defect in doped SrZrO₃ increased in the order, Al, Ga, Sc, Yb, Y, Rh, In. This indicates that there is a difference in the hydrogen concentration among these SrZrO₃ under the same equilibrium conditions.