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arXiv · 1811.07343

Spiral magnetic ordering of the Eu moments in EuNi$_{2}$As$_{2}$

W. T. Jin·N. Qureshi·Z. Bukowski·Y. Xiao·S. Nandi·M. Babij·Z. Fu·Y. Su·Th. Brückel
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Abstract

The ground-state magnetic structure of EuNi$_{2}$As$_{2}$ was investigated by single-crystal neutron diffraction. At base temperature, the Eu$^{2+}$ moments are found to form an incommensurate antiferromagnetic spiral-like structure with a magnetic propagation vector of $\mathit{k}$ = (0, 0, 0.92). They align ferromagnetically in the $\mathit{ab}$ plane with the moment size of 6.75(6) $μ_{B}$, but rotate spirally by 165.6(1)° around the $\mathit{c}$ axis from layer to layer. The magnetic order parameter in the critical region close to the ordering temperature, $\mathit{T_{N}}$ = 15 K, shows critical behavior with a critical exponent of $β_{Eu}$ = 0.34(1), consistent with the three-dimensional Heisenberg model. Moreover, within the experimental uncertainty, our neutron data is consistent with a model in which the Ni sublattice is not magnetically ordered.

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W. T. Jin, N. Qureshi, Z. Bukowski, Y. Xiao, S. Nandi, M. Babij, Z. Fu, Y. Su, Th. Brückel. 2018-11-18. Spiral magnetic ordering of the Eu moments in EuNi$_{2}$As$_{2}$. https://doi.org/10.1103/physrevb.99.014425

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