Density functional simulation of the BaZrO3 (011) surface structure

The atomic structure and charge redistribution of different terminations of BaZrO3 (011) surfaces have been studied using density functional simulations. We found that the O-terminated (011) flat surface had the smallest cleavage energy among (011) surfaces, but this value was still twice as large as for the formation of a pair of complimentary (001) surfaces. The density functional calculations allowed us to estimate the excess surface Gibb's free energy and to compare stability of different (011) surfaces as a function of chemical environment. In addition, we compared stability of BaZrO3 (011) surfaces with respect to BaZrO3 (001) surfaces. Within boundaries, where BaZrO3 does not decompose, only the Ba- and O-terminated (011) surfaces appeared to be stable. However, if (001) surfaces are also taken into consideration, the BaO-terminated (001) surface is the only stable surface among all considered (001) and (011) surfaces.