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Title: Atomic-scale electrochemistry on the surface of a manganite by scanning tunneling microscopy

The doped manganese oxides (manganites) have been widely studied for their colossal magnetoresistive effects, for potential applications in oxide spintronics, electroforming in resistive switching devices, and are materials of choice as cathodes in modern solid oxide fuel cells. However, little experimental knowledge of the dynamics of the surfaces of perovskite manganites at the atomic scale exists. Here, through in-situ scanning tunneling microscopy (STM), we demonstrate atomic resolution on samples of La{sub 0.625}Ca{sub 0.375}MnO{sub 3} grown on (001) SrTiO{sub 3} by pulsed laser deposition. Furthermore, by applying triangular DC waveforms of increasing amplitude to the STM tip, and measuring the tunneling current, we demonstrate the ability to both perform and monitor surface electrochemical processes at the atomic level, including formation of oxygen vacancies and removal and deposition of individual atomic units or clusters. Our work paves the way for better understanding of surface oxygen reactions in these systems.
Authors:
; ;  [1] ;  [2] ;  [3] ;  [1] ;  [2] ;  [2]
  1. Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)
  2. (United States)
  3. UT/ORNL Bredesen Center, University of Tennessee, Knoxville, Tennessee 37996 (United States)
Publication Date:
OSTI Identifier:
22398867
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 106; Journal Issue: 14; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CALCIUM COMPOUNDS; CATHODES; DOPED MATERIALS; ELECTROCHEMISTRY; ELECTRODEPOSITION; ENERGY BEAM DEPOSITION; LANTHANUM COMPOUNDS; LASER RADIATION; MAGNETORESISTANCE; MANGANESE OXIDES; OXYGEN; PULSED IRRADIATION; SCANNING TUNNELING MICROSCOPY; SOLID OXIDE FUEL CELLS; STRONTIUM TITANATES; SURFACES; TUNNEL EFFECT; VACANCIES; WAVE FORMS