Berlin 2012 – scientific programme

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DS: Fachverband Dünne Schichten

DS 38: Poster III: Resistive switching (jointly with DF, KR, HL); Thermoelectric materials (Focused session); Micro- and nanopatterning (jointly with O); Ion irradiation effects

DS 38.31: Poster

Thursday, March 29, 2012, 17:30–19:00, Poster E

Transport anisotropy of LaAlO₃/SrTiO₃ interfaces on chemically patterned SrTiO₃ — •Michael Foerster¹, Romain Bachelet¹, Vladimir Laukhin^1,2, Josep Fontcuberta¹, Gervasi Herranz¹, and Florencio Sanchez¹ — ¹Institut de Ciència de Materials de Barcelona ICMAB-CSIC, Campus de la UAB, 08193 Bellaterra, Catalonia, Spain — ²Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona, Catalonia, Spain

A few years ago high mobility electronic transport was found at the interface between the wide bandgap insulators SrTiO₃ and LaAlO₃ [1]. This conductive layer is confined to a few unit cells around the interface and it appears when LaAlO₃ layers with thickness above 3-4 unit cells are grown on SrTiO₃. It is known that TiO₂/LaO interfaces are conductive, while SrO/AlO₂ interfaces are insulating.

Here we exploited this way to control the interface properties to produce large scale functional nanostructures. TiO₂/AlO - SrO /LaO₂ modulated interfaces have been prepared using thermally treated SrTiO₃ surfaces with self-organized patterned chemical termination. The interface transport properties are found to be controlled according to these interface patterns. While the influence of the interface topology, e.g. terrace steps, is negligible, a strong transport anisotropy is observed when large-scale well oriented chemical patterns are realized. Our results show that bottom-up engineering of the interface chemical composition is a suitable strategy to influence the transport properties on large scales.

References [1] A. Ohtomo and H.Y. Hwang, Nature 427, 423 (2004).