Combining B3PW hybrid exchange-correlation functional within the density

functional theory and a super-cell model, first-principles calculations were made of

the electronic structures of both the ideal PbZrO3 (001) surface (with ZrO2- and

PbO-terminations) and of a neutral oxygen vacancy; also termed the F center. The

atomic relaxation and electronic density redistributions were considered. A

thermodynamic analysis of pure surfaces indicated that ZrO2 termination was energetically more favorable than was PbO termination. The O vacancy on the

ZrO2-surface attracted about 0.3e (0.7e in the bulk PbZrO3), while the remaining

electron density from the missing O2- ion was localized mostly on atoms nearest to

a vacancy. The calculated defect formation energy was smaller than in the bulk,

and was expected to lead to vacancy segregation to the surface. Unlike Ti-based

perovskites, the vacancy-induced (deep) energy level in PbZrO3 lay in the middle

of the band-gap.

The Electronic Properties of an Oxygen Vacancy at ZrO2-Terminated (001)

Surfaces of a Cubic PbZrO3: Computer Simulations from the First Principles.

E.A.Kotomin, S.Piskunov, Y.F.Zhukovskii, R.L.Eglitis, A.Gopejenko, D.E.Ellis:

Physical Chemistry Chemical Physics, 2008, 10[29], 4258-63