Electronic and Magnetic Properties of EuNi<sub>2-x</sub>Sb<sub>2</sub> Structural Variants
ORAL
Abstract
XRD, magnetic susceptibility, magnetization, heat capacity, and resistivity results are reported for single crystals of two structural variants of EuNi2-xSb2. While the CaBe2Ge2-type structure forms with a stoichiometric ratio, the ThCr2Si2-type structure exhibits a Ni site vacancy of 18%. Both systems show Curie-Weiss temperature dependence at elevated temperatures, indicating an antiferromagnetic exchange interaction between the Eu2+ ions. At low temperatures, the different structural environments give rise to distinct ordering behavior. The CaBe2Ge2-variant first orders antiferromagnetically near TN2=6.9K and then undergoes a first order transition at T3=4.6K. The ThCr2Si2-variant orders antiferromagnetically at TN1=5.6K. The 4f entropy recovered by the antiferromagnetic ordering is consistent with the predicted J=7/2 Hund's rule multiplet values for the ThCr2Si2-variant, while it is reduced for the CaBe2Ge2-variant. Thus, EuNi2-xSb2 emerges as a useful system in which to study the impact of structural variation on electronic correlations.
*This work was performed at the NHMFL which is supported by NSF Cooperative Agreement DMR-1644779 and the State of Florida. Synthesis and material characterization was supported by CAST, an EFRC funded by the US DOE under Award DE-SC0016568.
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Presenters
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William Nelson
- National High Magnetic Field Laboratory/Florida State University
- Florida State Univ
- Physics, NHMFL, Florida State University