Atomic rearrangements at the TiO₂-terminated (001)SrTiO₃ surface and growth of thin LaMnO₃ films

¹ Ioffe Physical-Technical institute, RAS - 194021 St. Petersburg, Russia
² Chalmers University of Technology - S-41296 Gothenburg, Sweden, EU
³ Skobeltsyn Institute of Nuclear Physics, Department of Physics, Moscow State University - 119899 Moscow, Russia

^(a) alexei.kalaboukhov@chalmers.se

Received: 4 April 2013
Accepted: 31 May 2013

Abstract

SrTiO₃ is commonly used as a substrate for growth of various oxide films. Different reconstructions at the SrTiO₃ surface have been claimed. A question is whether these survive subsequent depositions of thin films and influence film properties. Medium energy ion scattering (MEIS) was used to probe structure and composition of the surface layer of a TiO₂-terminated (001)SrTiO₃ single-crystal substrate and 1–4 unit cell (u.c.) thick LaMnO₃ epilayers. Aligned spectra indicate enrichment of Ti at the surface and a TiO₂ double-layer (DL) configuration. The DL arrangement survives pulsed-laser deposition of LaMnO₃ in a background of high oxygen pressure (5 × 10⁻² mbar) while it is destroyed at lower oxygen pressure (10⁻⁴ mbar). Simulations of random MEIS spectra indicate substantial interdiffusion and La doping of the substrate surface but all interfaces are nevertheless insulating.