1202.4570 (B. Joakim Nyman et al.)

Oxygen vacancy segregation and space-charge effects in grain boundaries
of dry and hydrated BaZrO3    [PDF]

B. Joakim Nyman, Edit E. Helgee, Göran Wahnström

A space-charge model is applied to describe the equilibrium effects of
segregation of double-donor oxygen vacancies to grain boundaries in dry and wet
acceptor-doped samples of the perovskite oxide BaZrO3. The grain boundary core
vacancy concentrations and electrostatic potential barriers resulting from
different vacancy segregation energies are evaluated. Density-functional
calculations on vacancy segregation to the mirror-symmetric \Sigma 3 (112)
[-110] tilt grain boundary are also presented. Our results indicate that oxygen
vacancy segregation can be responsible for the low grain boundary proton
conductivity in BaZrO3 reported in the literature.

View original: http://arxiv.org/abs/1202.4570