Dynamic layer rearrangement during growth of layered oxide films by molecular beam epitaxy

J H Lee; G Luo; I C Tung; S H Chang; Z Luo; M Malshe; M Gadre; A Bhattacharya; S M Nakhmanson; J A Eastman; H Hong; J Jellinek; D Morgan; D D Fong; J W Freeland

doi:10.1038/nmat4039

Dynamic layer rearrangement during growth of layered oxide films by molecular beam epitaxy

Nat Mater. 2014 Sep;13(9):879-83. doi: 10.1038/nmat4039. Epub 2014 Aug 3.

Authors

J H Lee¹, G Luo², I C Tung³, S H Chang⁴, Z Luo⁵, M Malshe⁶, M Gadre⁷, A Bhattacharya⁸, S M Nakhmanson⁹, J A Eastman⁴, H Hong¹⁰, J Jellinek⁶, D Morgan⁷, D D Fong⁴, J W Freeland¹⁰

Affiliations

¹ 1] X-ray Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA [2] [3].
² 1] Department of Materials Science &Engineering, University of Wisconsin-Madison, 1509 University Avenue Madison, Wisconsin 53706, USA [2].
³ 1] X-ray Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA [2] Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, USA.
⁴ Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
⁵ 1] Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA [2] National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230026, China.
⁶ Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
⁷ Department of Materials Science &Engineering, University of Wisconsin-Madison, 1509 University Avenue Madison, Wisconsin 53706, USA.
⁸ 1] Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA [2] Center for Nanoscale Materials, Argonne National Laboratory, Argonne, Illinois 60439, USA.
⁹ Department of Materials Science &Engineering, and Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269, USA.
¹⁰ X-ray Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.

PMID: 25087067
DOI: 10.1038/nmat4039

Abstract

The A(n+1)B(n)O(3n+1) Ruddlesden-Popper homologous series offers a wide variety of functionalities including dielectric, ferroelectric, magnetic and catalytic properties. Unfortunately, the synthesis of such layered oxides has been a major challenge owing to the occurrence of growth defects that result in poor materials behaviour in the higher-order members. To understand the fundamental physics of layered oxide growth, we have developed an oxide molecular beam epitaxy system with in situ synchrotron X-ray scattering capability. We present results demonstrating that layered oxide films can dynamically rearrange during growth, leading to structures that are highly unexpected on the basis of the intended layer sequencing. Theoretical calculations indicate that rearrangement can occur in many layered oxide systems and suggest a general approach that may be essential for the construction of metastable Ruddlesden-Popper phases. We demonstrate the utility of the new-found growth strategy by performing the first atomically controlled synthesis of single-crystalline La3Ni2O7.