Ultrathin BaTiO3 templates for multiferroic nanostructures

Authors

Xumen Chen, University of Nebraska-Lincoln
Seolun Yang, Sook-Myung Women’s University, Seoul, Korea
Ji-Hyun Kim, Sook-Myung Women’s University, Seoul, Korea
Hyung-Do Kim, Pohang Acceleration Laboratory (PAL), Pohang, Korea
Jae-Sung Kim, Sook-Myung Women’s University, Seoul, Korea
Geoffrey Rojas, University of Nebraska-LincolnFollow
Ralph Skomski, University of Nebraska-LincolnFollow
Haidong Lu, University of Nebraska-LincolnFollow
Anand Bhattacharya, Argonne National LaboratoryFollow
Tiffany Santos, Argonne National Laboratory
Nathan Guisinger, Argonne National LaboratoryFollow
Matthias Bode, Argonne National LaboratoryFollow
Alexei Gruverman, University of Nebraska-LincolnFollow
Axel Enders, University of Nebraska–LincolnFollow

Date of this Version

8-2011

Citation

New Journal of Physics 13 (2011) 083037 (10pp); doi:10.1088/1367-2630/13/8/083037

Comments

Copyright IOP Publishing Ltd and Deutsche Physikalische Gesellschaft

Abstract

The structural, electronic and dielectric properties of high-quality ultrathin BaTiO₃ films were investigated. The films, which were grown by ozone-assisted molecular beam epitaxy on Nb-doped SrTiO₃(001) substrates and have thicknesses as low as 8 unit cells (u.c.) (3.2 nm), are unreconstructed and atomically smooth with large crystalline terraces. A strain-driven transition to three-dimensional (3D) island formation is observed for films of 13 u.c. thickness (5.2 nm). The high structural quality of the surfaces, together with dielectric properties similar to bulk BaTiO₃ and dominantly TiO₂ surface termination, makes these films suitable templates for the synthesis of high-quality metaloxide multiferroic heterostructures for the fundamental study and exploitation of magneto-electric effects, such as a recently proposed interface effect in Fe/BaTiO₃ heterostructures based on Fe–Ti interface bonds.