Oxygen vacancy clustering and electron localization in oxygen-deficient SrTiO(3): LDA + U study.

نویسندگان

  • Do Duc Cuong
  • Bora Lee
  • Kyeong Mi Choi
  • Hyo-Shin Ahn
  • Seungwu Han
  • Jaichan Lee
چکیده

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.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Tuning LDA+U for electron localization and structure at oxygen vacancies in ceria.

We examine the real space structure and the electronic structure (particularly Ce4f electron localization) of oxygen vacancies in CeO(2) (ceria) as a function of U in density functional theory studies with the rotationally invariant forms of the LDA+U and GGA+U functionals. The four nearest neighbor Ce ions always relax outwards, with those not carrying localized Ce4f charge moving furthest. Se...

متن کامل

Oxygen Vacancy Linear Clustering in a Perovskite Oxide.

Oxygen vacancies have been implicitly assumed isolated ones, and understanding oxide materials possibly containing oxygen vacancies remains elusive within the scheme of the isolated vacancies, although the oxygen vacancies have been playing a decisive role in oxide materials. Here, we report the presence of oxygen vacancy linear clusters and their orientation along a specific crystallographic d...

متن کامل

Ab Initio DFT+U Analysis of Oxygen Vacancy Formation and Migration

Incorporating mixed oxygen-ion-electron conducting (MIEC) cathode materials is a promising strategy to make intermediate-temperature solid oxide fuel cells (IT-SOFCs) viable; however, a lack of fundamental understanding of oxygen transport in these materials limits their development. Density functional theory plus U (DFT+U) calculations are used to investigate how the Sr concentration affects t...

متن کامل

DFT Study on Oxygen-Vacancy Stability in Rutile/Anatase TiO2: Effect of Cationic Substitutions

In this study, a full-potential density functional theory was used to investigate the effects of Ti substitution by different cations. In both rutile and anatase, Ti atom was replaced by Ce, Au, Sn, Ag, Mo, Nb, Zr, and Y. Phase stability, electronic structure and formation energy of oxygen vacancy were compared for rutile and anatase. The results indicated that substitution of Ce and Zr increas...

متن کامل

Bandgap Control of the Oxygen-Vacancy-Induced Two-Dimensional Electron Gas in SrTiO

greater than the bulk value, depending on the deposition temperature. There is no signifi cant change in density and cationic ratio of the oxide so the effect is attributed to Sr/Ti antisite defects, an attribution supported by density functional theory calculations. It was found that the bandgap enhancement signifi cantly changes the electronic and magnetic phases in the oxygen-vacancy-induced...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Physical review letters

دوره 98 11  شماره 

صفحات  -

تاریخ انتشار 2007