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arXiv · 1704.07148

Interface magnetism and electronic structure: ZnO(0001)/Co3O4(111)

Igor Kupchak·Natalia Serpak·Anatoli Shkrebtii·Roland Hayn
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Abstract

We have studied the structural, electronic and magnetic properties of spinel $\rm Co_3O_4$(111) surfaces and their interfaces with ZnO (0001) using density functional theory (DFT) within the Generalized Gradient Approximation with on-site Coulomb repulsion term (GGA+U). Two possible forms of spinel surface, containing $\rm Co^{2+} $ and $\rm Co^{3+} $ ions and terminated with either cobalt or oxygen ions were considered, as well as their interface with zinc oxide. Our calculations demonstrate that $\rm Co^{3+} $ ions attain non-zero magnetic moments at the surface and interface, in contrast to the bulk, where they are not magnetic, leading to the ferromagnetic ordering. Since heavily Co-doped ZnO samples can contain $\rm Co_3O_4 $ secondary phase, such a magnetic ordering at the interface might explain the origin of the magnetism in these diluted magnetic semiconductors (DMS).

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Igor Kupchak, Natalia Serpak, Anatoli Shkrebtii, Roland Hayn. 2018-02-20. Interface magnetism and electronic structure: ZnO(0001)/Co3O4(111). https://doi.org/10.1103/physrevb.97.125304

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