The solid solution Eu${}_{1-x}$Sr${}_x$AuIn

EuAuIn and SrAuIn (TiNiSi type structure, space group Pnma) form a complete solid solution Eu${}_{1-x}$Sr${}_x$AuIn. Samples with x = 0.2, 0.4, 0.5, 0.6 and 0.8 were prepared by melting of the elements in sealed tantalum ampoules followed by slow cooling. The samples were characterized through Guinier powder patterns. The X-ray data confirm Vegard type behavior. The crystal structures of Eu${}_{0.8}$Sr${}_{0.2}$AuIn and Eu${}_{0.5}$Sr${}_{0.5}$Au${}_{1.02}$In${}_{0.98}$ were refined from single-crystal X-ray diffraction data in order to confirm the Eu/Sr site occupancies. Temperature-dependent magnetic susceptibility data confirm divalent europium. The Néel temperature linearly drops from 21.0 K for EuAuIn and long-range magnetic ordering is still present in the x = 0.8 sample with T${}_N$ = 4.1 K. Low-field measurements indicate two successive magnetic ordering temperatures for all samples, resulting from a complex interplay of antiferromagnetic and ferromagnetic interactions, similar to the tetrelides EuMgX (X = Si, Ge, Sn). ${}^{151}$Eu Mössbauer spectra confirm the divalent ground state and show complex magnetic hyperfine field splitting at 6 K. (© 2020 The Authors. Published by Wiley‐VCH GmbH)