Room temperature ferromagnetism in Mn ion implanted epitaxial ZnO films

✍ Scribed by Hill, D. H. ;Arena, D. A. ;Bartynski, R. A. ;Wu, P. ;Saraf, G. ;Lu, Y. ;Wielunski, L. ;Gateau, R. ;Dvorak, J. ;Moodenbaugh, A. ;Yeo, Yung Kee

• Book ID: 105363821
• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 201 KB
• Volume: 203
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/pssa.200622134

✦ Synopsis

Abstract

Epitaxial ZnO films of ∼450 nm thicknesses were grown by MOCVD on r‐sapphire and doped by implantation of 200 keV Mn ions to a dose of 5 × 10^16^ ions/cm^2^. The structural, chemical, and magnetic properties of the films were investigated with X‐ray diffraction (XRD), Rutherford backscattering spectrometry (RBS), X‐ray absorption spectroscopy (XAS) and SQUID magnetometry. XRD and RBS show both Mn‐doped ZnO and pure ZnO epitaxial layers in the as‐implanted film, which is ferromagnetic at 5 K but nonmagnetic at room temperature. For the as‐implanted materials, only Mn^2+^ ions are observed with XAS. Post‐implantation annealing partially recovers the lattice damage and redistributes Mn into the entire ZnO film; in addition, Mn^2+^ ions are converted to a mixture of Mn^3+^ and Mn^4+^, and ferromagnetism is now observed above 300 K. Our results show that ion implantation is a viable route for achieving room temperature ferromagnetism in epitaxial ZnO films. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)