TY - JOUR
T1 - Sensitivity of the magnetic properties of the ZnCr2O4 and MgCr2O4 spinels to nonstoichiometry
AU - Dutton, S. E.
AU - Huang, Q.
AU - Tchernyshyov, O.
AU - Broholm, C. L.
AU - Cava, R. J.
PY - 2011/2/11
Y1 - 2011/2/11
N2 - We report that small amounts of metal atom nonstoichiometry are possible in the ZnCr2O4 and MgCr2O4 spinels. The nonstoichiometry, though less than 2%, significantly impacts TN and the nature of the magnetic correlations above TN. The Zn 1+xCr2-xO4 spinel is particularly sensitive. While stoichiometric ZnCr2O4 displays antiferromagnetic short-range correlations in the susceptibility above TN, ferromagnetic correlations are observed in nonstoichiometric, hole-doped Zn 1+xCr2-xO4. The Mg1+xCr 2-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 nonmagnetic Ga3+ substituted on the Cr3+ site to separate the effects of static site disorder and hole doping.
AB - We report that small amounts of metal atom nonstoichiometry are possible in the ZnCr2O4 and MgCr2O4 spinels. The nonstoichiometry, though less than 2%, significantly impacts TN and the nature of the magnetic correlations above TN. The Zn 1+xCr2-xO4 spinel is particularly sensitive. While stoichiometric ZnCr2O4 displays antiferromagnetic short-range correlations in the susceptibility above TN, ferromagnetic correlations are observed in nonstoichiometric, hole-doped Zn 1+xCr2-xO4. The Mg1+xCr 2-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 nonmagnetic Ga3+ substituted on the Cr3+ site to separate the effects of static site disorder and hole doping.
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U2 - 10.1103/PhysRevB.83.064407
DO - 10.1103/PhysRevB.83.064407
M3 - Article
AN - SCOPUS:79961043162
SN - 1098-0121
VL - 83
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 6
M1 - 064407
ER -