Surface effects on the orbital order in the single-layered manganite La0.5Sr1.5MnO4

TitleSurface effects on the orbital order in the single-layered manganite La0.5Sr1.5MnO4
Publication TypeJournal Article
Year of Publication2007
AuthorsWakabayashi Y, Upton MH, Grenier S, Hill JP, Nelson CS, Kim JW, Ryan PJ, Goldman AI, Zheng H, Mitchell JF
Journal TitleNature Materials
Volume6
Pages972-976
Date PublishedDec
Type of ArticleArticle
ISBN Number1476-1122
Accession NumberISI:000251317000020
Keywordsinterface, physics, PLANE, ROD, scattering, transition
Abstract

The question of how bulk electronic order is terminated at a surface is an intriguing one, and one with possible practical implications-for example in nanoscaled systems that may be characterized by their surface behaviour. One example of such order is orbital order, and in principle it should be possible to probe the termination of this order with surface X-ray scattering. Here, we report the first observation of the scattering arising from the termination of bulk orbital order at the surface of a crystal-so-called 'orbital truncation rods'. The measurements, carried out on a cleaved perovskite, La0.5Sr1.5MnO4, reveal that whereas the crystallographic surface is atomically smooth, the orbital 'surface', which is observed through the atomic displacements caused by the orbital order, is much rougher, with a typical scale of the surface roughness of similar to 7 angstrom. Interestingly, the temperature dependence of this scattering shows evidence of a surface-induced second-order transition.

DOI10.1038/nmat2061
Alternate JournalNat. Mater.