The electronic properties of an oxygen vacancy at ZrO2-terminated (001) surfaces of a cubic PbZrO3: computer simulations from the first principles

Abstract

Combining B3PW hybrid exchange-correlation functional within the density functional theory (DFT) and a supercell model, we calculated from the first principles the electronic structure of both ideal PbZrO(3) (001) surface (with ZrO(2)- and PbO-terminations) and a neutral oxygen vacancy also called the F center. The atomic relaxation and electronic density redistributions are discussed. Thermodynamic analysis of pure surfaces indicates that ZrO(2) termination is energetically more favorable than PbO-termination. The O vacancy on the ZrO(2)-surface attracts approximately 0.3 e (0.7 e in the bulk PbZrO(3)), while the remaining electron density from the missing O(2-) ion is localized mostly on atoms nearest to a vacancy. The calculated defect formation energy is smaller than in the bulk which should lead to the vacancy segregation to the surface. Unlike Ti-based perovskites, the vacancy-induced (deep) energy level lies in PbZrO(3) in the middle of the band gap.

Ab initio Calculations of YAlO3 and ABO3 Perovskite (001), (011) and (111) Surfaces, Interfaces and Defects

“…Our B3PW calculated nearest atom displacements surrounding the F-center in ABO 3 perovskites are collected in Table III and compared with related results obtained for other ABO 3 perovskites [38][39][40][41]43]. As we can see from Table III, the two nearest to the Fcenter Ti atoms are by 1.06% of a 0 repulsed in the BaTiO 3 from the oxygen vacancy.…”

“…Finally, the ABO 3 perovskite, or for example, the BaTiO 3 bulk F-center calculations were carried out using 3 x 3 x 3 times extended supercell model. Such a supercell in our calculations contains 134 atoms as well as one isolated F-center defect [38,40,43].…”

“…Oxygen vacancy (V 0 ) (so-called neutral F-center) in ABO 3 perovskites traps two electrons. Experimental and theoretical investigations of F-centres in complex ABO 3 matrixes are a very important topic, since the F-center is the best known classical point defect, which strongly affects all material properties [37][38][39][40][41][42][43][44].…”

Comparative ab initio calculations of SrTiO3/BaTiO3 and SrZrO3/PbZrO3 (0 0 1) heterostructures

“…The B3PW functional [21] used in the current study contains a ''hybrid'' of the DFT exchange and correlation functionals with exact non-local Hartree-Fock (HF) exchange. Standard BTO, STO, PZO and SZO low index (0 0 1) surfaces have been carefully studied by us already previously [2,1,22,23,7,8,12,6,13].…”

Comparative Ab initio Calculations for ABO3 Perovskite (001), (011) and (111) as well as YAlO3 (001) Surfaces and F Centers

“…Since the F-center is the best known classical point defect, which strongly affects all ABO3 perovskite properties, their theoretical and experimental investigation is a very hot topic. Nevertheless, most of the experimental and theoretical studies in the ABO3 perovskite materials are performed for the bulk F-center defects [20][21][22][23][24][25][26][27][28][29]. The BO2 and especially AO-terminated ABO3 perovskite (001) surface F-centers centers are considerably less studied both theoretically and experimentally.…”