Ferromagnetic behavior above room temperature of Fe-ion-lmplanted ZnO

Y. Y. Song, K. S. Park, D. V. Son, S. C. Yu, H. J. Kang, S. W. Shin, C. N. Whang, Jong Heun Lee, J. H. Song, K. W. Lee

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)

Abstract

Zinc-oxide (0001) single crystals with a 0.5 mm thickness were prepared, and then 80 keV Fe ions with a dose of 3 × 1016 ions/cm 2 were implanted into the ZnO single crystals at 350°C The implanted samples were post-annealed at 700, 800 and 900°C by rapid thermal annealing in an N2 atmosphere for 5 min to remove the ion-implantation damage. The structure and the magnetic properties of Fe-ion-implanted ZnO were investigated by using X-ray diffraction and a superconducting quantum interference device magnetometer. The carrier transport properties were measured in the range from 5 K to 300 K. The X-ray diffraction results showed an island peak near 37°C, which was identified as ZnO 2. The magnetization curve showed hysteresis loops at 5 K in the samples annealed at 700 and 800°C, showing ferromagnetism. Hysteresis loops were observed at 300 K in the samples annealed at 700°C The temperature dependence of the magnetization was taken in field cooling (FC) and zero field cooling (ZFC) in the samples annealed at 700°C The difference magnetization (ΔM) between the FC and the ZFC magnetizations did not converge to a zero value even at 340 K, showing ferromagnetism above room temperature. The magnetoresistance (MR) curve showed negative curvature up to 150 K which could be explained with the delocalized d state of ZnO implanted with Fe ions.

Original languageEnglish
Pages (from-to)1706-1710
Number of pages5
JournalJournal of the Korean Physical Society
Volume50
Issue number6
DOIs
Publication statusPublished - 2007 Jun

Keywords

  • Fe-implanted ZnO
  • Ferromagnetism

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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