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Ferromagnetism in substituted zinc oxide

M. Venkatesan·C. B. Fitzgerald·J. G. Lunney·J. M. D. Coey
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Abstract

Room-temperature ferromagnetism is observed in (110) oriented ZnO films containing 5 at % of Sc, Ti, V, Fe, Co or Ni, but not Cr, Mn or Cu ions. There are large moments, 1.9 and 0.5 muB/atom for Co- and Ti-substituted oxides, respectively. Sc-substituted ZnO shows also a moment of 0.3 muB/Sc. Magnetization is very anisotropic, with variations of up to a factor three depending on the orientation of the applied field relative to the R-cut sapphire substrates. Results are interpreted in terms of a spin-split donor impurity band model, which can account for ferromagnetism in insulating or conducting high-k oxides with concentrations of magnetic ions that lie far below the percolation threshold. The variation of the ferromagnetism with oxygen pressure used during film growth is evidence of a link between ferromagnetism and defect concentration.

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M. Venkatesan, C. B. Fitzgerald, J. G. Lunney, J. M. D. Coey. 2004-06-29. Ferromagnetism in substituted zinc oxide. https://doi.org/10.1103/physrevlett.93.177206

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