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arXiv · 1101.0753

The Sensitivity of the Magnetic Properties of the ZnCr2O4 and MgCr2O4 Spinels to Non-stoichiometry

S. E. Dutton·Q. Huang·O. Tchernyshyov·C. L. Broholm·R. J. Cava
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Abstract

We report that small amounts of metal atom non-stoichiometry are possible in the ZnCr2O4 and MgCr2O4 spinels. The non-stoichiometry, though less than 2%, significantly impacts TN and the nature of the magnetic correlations above TN. The Zn1+xCr2-xO4 spinel is particularly sensitive. While stoichiometric ZnCr2O4 displays antiferromagnetic short range correlations in the susceptibility above TN, ferromagnetic correlations are observed in non-stoichiometric, hole doped Zn1+xCr2-xO4. The Mg1+xCr2-xO4 spinels are less profoundly affected by non-stoichiometry, though significant changes are also observed. We contrast the magnetic properties of Zn1+xCr2-xO4 and Mg1+xCr2-xO4 (x=0, 0.02, 0.04) with those of materials with the equivalent amounts of isovalent non-magnetic Ga3+ substituted on the Cr3+ site to separate the effects of static site disorder and hole doping.

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S. E. Dutton, Q. Huang, O. Tchernyshyov, C. L. Broholm, R. J. Cava. 2011-01-04. The Sensitivity of the Magnetic Properties of the ZnCr2O4 and MgCr2O4 Spinels to Non-stoichiometry. https://doi.org/10.1103/physrevb.83.064407

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