Cationic Disorder and Phase Segregation in LaAlO3/SrTiO3 Heterointerfaces Evidenced by Medium-Energy Ion Spectroscopy
Journal article, 2009

Medium-energy ion spectroscopy (MEIS) has been used to study the depth profile and deduce the distribution of possible cationic substitutions in LaAlO3/SrTiO3 (LAO/STO) heterointerfaces. Analysis of La and Sr peaks in aligned and random MEIS spectra indicates that the surface layers of LAO on an STO substrate are not homogeneous and stoichiometric if the film thickness is less than 4 unit cell layers. This is possibly caused by a redistribution of La and Sr at the interface. Kelvin probe force microscopy reveals an inhomogeneous distribution of the surface potential in a 4 unit cell LAO film, indicating micrometer-sized regions of different compositions. Our findings provide a novel view on the microstructural origin of the electrically conductive interfaces.

polar interfaces

MEIS

2DEG

perovskite oxides

Kelvin probe AFM

Author

Alexei Kalaboukhov

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Iouri Boikov

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Vladimir Popok

University of Gothenburg

I.T. Serenkov

Russian Academy of Sciences

V.I. Sakharov

University of Gothenburg

Robert Gunnarsson

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Eva Olsson

Chalmers, Applied Physics, Microscopy and Microanalysis

Nikolina Tuzla

Chalmers, Applied Physics, Microscopy and Microanalysis

Johan Börjesson

Chalmers, Applied Physics, Microscopy and Microanalysis

Tord Claeson

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Dag Winkler

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Physical Review Letters

0031-9007 (ISSN) 1079-7114 (eISSN)

Vol. 103 14 146101-

Areas of Advance

Nanoscience and Nanotechnology (2010-2017)

Materials Science

Subject Categories

Condensed Matter Physics

DOI

10.1103/PhysRevLett.103.146101

More information

Latest update

7/4/2018 1