Journal of the Korean Physical Society

pISSN 0374-4884 eISSN 1976-8524


Condensed Matter

J. Korean Phy. Soc. 2010; 56(2): 562-566

Published online February 12, 2010

Copyright © The Korean Physical Society.

Observation of the Strong Negative Anomalous Hall Effect in Co Ion-implanted ZnO Single Crystals

Hee Jae Kang, Y. Y. Song, K. H. Park, K. S. Park, S. K. Oh, D. S. Yang, S. W. Shin, J. H. Song


The 80 keV Co ions with a dose of 3 ?1016 ions/cm2 were implanted into high quality 0.5-mm-thick ZnO (0001) single crystals with very low carrier concentration of n = 2.0?013/cm3. The implanted samples were post-annealed at 700, 800 and 900 ¡É by rapid thermal annealing (RTA) in a N2 atmosphere. The structural, magnetic and transport properties of Co-ion-implanted ZnO were investigated. The Co K-edge Extended X-ray Absorption Fine Structure revealed the coexistence of Co-Co and Co-Zn bonds. The Co ions substituted into Zn sites form Zn1-xCoxO. Magnetoresistance (MR) data showed sign change from positive to negative between 50 K and 77 K. Strong negative anomalous Hall effect (SNAHE) was observed in the temperature range with positive MR. The sign change in the observed SNAHE seems to support the theory of Burkov and Balent.