Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Site Tools

  • AAAS
  • Subscribe
  • Feedback

Site Search

Search Advanced

Published Online October 11, 2007
Science DOI: 10.1126/science.1149338

Research Articles

Submitted on August 16, 2007
Accepted on October 2, 2007

Orbital Reconstruction and Covalent Bonding at an Oxide Interface

J. Chakhalian 1*, J. W. Freeland 2, H.-U. Habermeier 3, G. Cristiani 3, G. Khaliullin 3, M. van Veenendaal 4, B. Keimer 3

1 University of Arkansas, Fayetteville, AR 72701, USA.; Max Planck Institute for Solid State Research, D-70569 Stuttgart, Germany.
2 Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA.
3 Max Planck Institute for Solid State Research, D-70569 Stuttgart, Germany.
4 Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA.; Department of Physics, Northern Illinois University, Dekalb, IL 60115, USA.

* To whom correspondence should be addressed.
J. Chakhalian , E-mail: jchakhal{at}uark.edu

Orbital reconstructions and covalent bonding must be considered as important factors in the rational design of oxide heterostructures with engineered physical properties. We have investigated the interface between high-temperature superconducting (Y,Ca)Ba2Cu3O7 and metallic La2/3Ca1/3MnO3 by resonant x-ray spectroscopy. A charge of about -0.2e is transferred from Mn to Cu ions across the interface and induces a major reconstruction of the orbital occupation and orbital symmetry in the interfacial CuO2 layers. In particular, the Cu d3z2-r2 orbital, which is fully occupied and electronically inactive in the bulk, is partially occupied at the interface. Supported by exact-diagonalization calculations, these data indicate the formation of a strong chemical bond between Cu and Mn atoms across the interface. Orbital reconstructions and associated covalent bonding are thus important factors determining the physical properties of oxide heterostructures.




ADVERTISEMENT
Click Me!

ADVERTISEMENT
Click Me!

To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)