Ferromagnetic interaction between Cu ions in the bulk region of Cu-doped ZnO nanowires

T. Kataoka, Y. Yamazaki, V. R. Singh, A. Fujimori*, F. H. Chang, H. J. Lin, D. J. Huang, C. T. Chen, G. Z. Xing, J. W. Seo, C. Panagopoulos, Tao Wu

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

43 Scopus citations

Abstract

We have studied the electronic structure and the magnetism of Cu-doped ZnO nanowires, which have been reported to show ferromagnetism at room temperature, by x-ray photoemission spectroscopy (XPS), x-ray absorption spectroscopy (XAS), and x-ray magnetic circular dichroism (XMCD). From the XPS and XAS results, we find that the Cu atoms are in the "Cu3+" state with mixture of Cu2+ in the bulk region (∼100 nm), and that Cu3+ ions are dominant in the surface region (∼5 nm), i.e., the surface electronic structure of the surface region differs from the bulk one. From the magnetic field and temperature dependencies of the XMCD intensity, we conclude that the ferromagnetic interaction in ZnO:Cu NWs comes from the Cu2+ and Cu3+ states in the bulk region, and that most of the doped Cu ions are magnetically inactive, probably because they are antiferromagnetically coupled with each other.

Original languageEnglish (US)
Article number153203
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume84
Issue number15
DOIs
StatePublished - Oct 14 2011

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

Fingerprint

Dive into the research topics of 'Ferromagnetic interaction between Cu ions in the bulk region of Cu-doped ZnO nanowires'. Together they form a unique fingerprint.

Cite this