Atomically precise interfaces from non-stoichiometric deposition

Y F Nie; Y Zhu; C-H Lee; L F Kourkoutis; J A Mundy; J Junquera; Ph Ghosez; D J Baek; S Sung; X X Xi; K M Shen; D A Muller; D G Schlom

doi:10.1038/ncomms5530

Atomically precise interfaces from non-stoichiometric deposition

Nat Commun. 2014 Aug 4:5:4530. doi: 10.1038/ncomms5530.

Authors

Y F Nie¹, Y Zhu², C-H Lee³, L F Kourkoutis⁴, J A Mundy⁵, J Junquera⁶, Ph Ghosez⁷, D J Baek⁸, S Sung⁵, X X Xi⁹, K M Shen¹⁰, D A Muller⁴, D G Schlom¹¹

Affiliations

¹ 1] Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853, USA [2] Laboratory of Atomic and Solid State Physics, Department of Physics, Cornell University, Ithaca, New York 14853, USA [3].
² 1] School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, USA [2].
³ Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853, USA.
⁴ 1] School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, USA [2] Kavli Institute at Cornell for Nanoscale Science, Ithaca, New York 14853, USA.
⁵ School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, USA.
⁶ Departamento de Ciencias de la Tierra y Física de la Materia Condensada, Universidad de Cantabria, Cantabria Campus Internacional, Avenida de los Castros s/n, 39005 Santander, Spain.
⁷ Theoretical Materials Physics, Université de Liège, B-4000 Sart-Tilman, Belgium.
⁸ School of Electrical and Computer Engineering, Cornell University, Ithaca, New York 14853, USA.
⁹ Department of Physics, Temple University, Philadelphia, Pennsylvania 19122, USA.
¹⁰ 1] Laboratory of Atomic and Solid State Physics, Department of Physics, Cornell University, Ithaca, New York 14853, USA [2] Kavli Institute at Cornell for Nanoscale Science, Ithaca, New York 14853, USA.
¹¹ 1] Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853, USA [2] Kavli Institute at Cornell for Nanoscale Science, Ithaca, New York 14853, USA.

PMID: 25088659
DOI: 10.1038/ncomms5530

Abstract

Complex oxide heterostructures display some of the most chemically abrupt, atomically precise interfaces, which is advantageous when constructing new interface phases with emergent properties by juxtaposing incompatible ground states. One might assume that atomically precise interfaces result from stoichiometric growth. Here we show that the most precise control is, however, obtained by using deliberate and specific non-stoichiometric growth conditions. For the precise growth of Sr(n+1)Ti(n)O(n+1) Ruddlesden-Popper (RP) phases, stoichiometric deposition leads to the loss of the first RP rock-salt double layer, but growing with a strontium-rich surface layer restores the bulk stoichiometry and ordering of the subsurface RP structure. Our results dramatically expand the materials that can be prepared in epitaxial heterostructures with precise interface control--from just the n = ∞ end members (perovskites) to the entire RP homologous series--enabling the exploration of novel quantum phenomena at a richer variety of oxide interfaces.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.