skip to main content

DOE PAGESDOE PAGES

This content will become publicly available on February 2, 2019

Title: Polarity compensation mechanisms on the perovskite surface KTaO 3(001)

The stacking of alternating charged planes in ionic crystals creates a diverging electrostatic energy—a “polar catastrophe”—that must be compensated at the surface. We used scanning probe microscopies and density functional theory to study compensation mechanisms at the perovskite potassium tantalate (KTaO 3) (001) surface as increasing degrees of freedom were enabled. The as-cleaved surface in vacuum is frozen in place but immediately responds with an insulator-to-metal transition and possibly ferroelectric lattice distortions. Annealing in vacuum allows the formation of isolated oxygen vacancies, followed by a complete rearrangement of the top layers into an ordered pattern of KO and TaO 2 stripes. The optimal solution is found after exposure to water vapor through the formation of a hydroxylated overlayer with ideal geometry and charge.
Authors:
 [1] ;  [2] ;  [1] ;  [1] ;  [1] ; ORCiD logo [3] ;  [2] ;  [1]
  1. Technische Univ. Wien, Vienna (Austria)
  2. Univ. of Vienna (Austria)
  3. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Publication Date:
Grant/Contract Number:
AC05-00OR22725
Type:
Accepted Manuscript
Journal Name:
Science
Additional Journal Information:
Journal Volume: 359; Journal Issue: 6375; Journal ID: ISSN 0036-8075
Publisher:
AAAS
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE
OSTI Identifier:
1429191