title: Oxygen vacancy clustering and electron localization in oxygen-deficient SrTiO(3): LDA + U study.
abstract: We find, using a local density approximation +Hubbard U method, that oxygen vacancies tend to cluster in a linear way in SrTiO(3), a prototypical perovskite oxide, accompanied by strong electron localization at the 3d state of the nearby Ti transition metal ion. The vacancy clustering and the associated electron localization lead to a profound impact on materials properties, e.g., the reduction in free-carrier densities, the appearance of characteristic optical spectra, and the decrease in vacancy mobility. The high stability against the vacancy migration also suggests the physical reality of the vacancy cluster.
authors.affiliation: School of Materials Science and Engineering, SungKyunKwan University, Suwon 440-746, Korea.
authors.forename: Do Duc
authors.initials: do D
authors.lastname: Cuong
authors.forename: Bora
authors.initials: B
authors.lastname: Lee
authors.forename: Kyeong Mi
authors.initials: KM
authors.lastname: Choi
authors.forename: Hyo-Shin
authors.initials: HS
authors.lastname: Ahn
authors.forename: Seungwu
authors.initials: S
authors.lastname: Han
authors.forename: Jaichan
authors.initials: J
authors.lastname: Lee