Atomic Scale Observations of Metal-Induced Gap States at <span class="aps-inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>{</mi><mn>222</mn><mi>}</mi></math></span> MgO/Cu Interfaces

D. A. Muller; D. A. Shashkov; R. Benedek; L. H. Yang; J. Silcox; D. N. Seidman

doi:10.1103/PhysRevLett.80.4741

Atomic Scale Observations of Metal-Induced Gap States at ${222}$ MgO/Cu Interfaces

D. A. Muller, D. A. Shashkov, R. Benedek, L. H. Yang, J. Silcox, and D. N. Seidman

Phys. Rev. Lett. 80, 4741 – Published 25 May 1998

Abstract

${} (222)$ MgO/Cu interfaces produced by internal oxidation are studied by electron energy loss spectroscopy (EELS) using an atomic sized electron beam. We determine interfacial chemistry of this interface with subnanometer spatial resolution and use EELS to measure directly the electronic states pertaining to the buried interface. O, K, and Cu $L_{2, 3}$ edges show the formation of metal-induced states within the band gap of MgO, at the interface (which we find to be O terminated). Both experiment and ab initio calculations find the metal-induced gap states to be strongly localized at the interface, resulting in a very small interface core-level shift.

Received 9 October 1997

DOI:https://doi.org/10.1103/PhysRevLett.80.4741

Authors & Affiliations

D. A. Muller^1,2, D. A. Shashkov³, R. Benedek³, L. H. Yang⁴, J. Silcox¹, and D. N. Seidman³

¹School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853
²Bell Laboratories, Lucent Technologies, Murray Hill, New Jersey 07974
³Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208
⁴Condensed Matter Physics Division, Lawrence Livermore National Laboratory, Livermore, California 94551