Magnetic coupling between Cr atoms doped at bulk and surface sites of ZnO

Q. Wang, Q. Sun, P. Jena, Y. Kawazoe

Research output: Contribution to journalArticlepeer-review

59 Citations (Scopus)

Abstract

Contrary to theoretical prediction that Cr-doped bulk ZnO is ferromagnetic, recent experiments on Cr-doped ZnO thin film reveal the coupling to be antiferromagnetic. Using first-principles calculations based on gradient corrected density functional theory, we show that a possible origin of this disagreement may be associated with the site preference of Cr. In bulk, when Cr substitutes Zn, bond contraction occurs and Cr atoms prefer to cluster around O atoms. The ferromagnetic coupling among Cr atoms is driven by Cr 3d and O 2p exchange interactions as in Cr2 O cluster. However, when Cr atoms replace Zn on the surface, due to the different bonding environment, bonds expand preventing Cr atoms from clustering around O atoms. Consequently, the coupling between Cr atoms becomes antiferromagnetic.

Original languageEnglish
Article number162509
Pages (from-to)1-3
Number of pages3
JournalApplied Physics Letters
Volume87
Issue number16
DOIs
Publication statusPublished - 2005 Oct 17

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

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