TY - JOUR
T1 - Magnetic coupling between Cr atoms doped at bulk and surface sites of ZnO
AU - Wang, Q.
AU - Sun, Q.
AU - Jena, P.
AU - Kawazoe, Y.
N1 - Copyright:
Copyright 2011 Elsevier B.V., All rights reserved.
PY - 2005/10/17
Y1 - 2005/10/17
N2 - 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.
AB - 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.
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U2 - 10.1063/1.2106023
DO - 10.1063/1.2106023
M3 - Article
AN - SCOPUS:28344452834
VL - 87
SP - 1
EP - 3
JO - Applied Physics Letters
JF - Applied Physics Letters
SN - 0003-6951
IS - 16
M1 - 162509
ER -