• Editors' Suggestion

Pushing the detection of cation nonstoichiometry to the limit

Michele Riva, Giada Franceschi, Qiyang Lu, Michael Schmid, Bilge Yildiz, and Ulrike Diebold
Phys. Rev. Materials 3, 043802 – Published 25 April 2019
PDFHTMLExport Citation

Abstract

Nanoscale complex-oxide thin films prepared by well-established growth techniques, such as pulsed-laser deposition or molecular-beam epitaxy, often exhibit compositions that deviate from the ideal stoichiometry. Even small variations in composition can lead to substantial changes in the technologically relevant electronic, magnetic, and optical properties of these materials. To assess the reasons behind this variability, and ultimately to allow tuning the properties of oxide films with precise control of the deposition parameters, high-resolution detection of the nonstoichiometry introduced during growth is needed. The resolution of current techniques, such as x-ray diffraction, fluorescence, or spectroscopy, is limited to estimating composition differences in the percent level, which is often insufficient for electronic-device quality. We develop an unconventional approach based on scanning tunneling microscopy for enabling the determination of cation imbalance introduced in thin films with exceptionally small detection limit. We take advantage of the well-controlled surface reconstructions on SrTiO3(110), and use the established relation between those reconstructions and the surface composition to assess the cation excess deposited in pulsed-laser grown SrTiO3(110) films. We demonstrate that a <0.1% change in cation nonstoichiometry is detectable by our approach. Furthermore, we show that, for thin films that accommodate all the nonstoichiometry at the surface, this method has no fundamental detection limit.

  • Figure
  • Figure
  • Figure
  • Received 25 November 2018

DOI:https://doi.org/10.1103/PhysRevMaterials.3.043802

©2019 American Physical Society

Physics Subject Headings (PhySH)

Condensed Matter, Materials & Applied PhysicsAtomic, Molecular & OpticalInterdisciplinary Physics

Authors & Affiliations

Michele Riva1,*, Giada Franceschi1, Qiyang Lu2, Michael Schmid1, Bilge Yildiz1,2, and Ulrike Diebold1

  • 1Institute of Applied Physics, TU Wien, Wiedner Hauptstraße 8-10/E134, 1040 Wien, Austria
  • 2Laboratory for Electrochemical Interfaces, Departments of Nuclear Science and Engineering, and Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA

  • *Corresponding author: riva@iap.tuwien.ac.at

Article Text (Subscription Required)

Click to Expand

Supplemental Material (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 3, Iss. 4 — April 2019

Reuse & Permissions
Access Options
CHORUS

Article Available via CHORUS

Download Accepted Manuscript
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review Materials

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×