A 151Eu Mossbauer spectroscopic and magnetic susceptibility investigation of the intermetallic compounds EuTIn (T = Zn, Pd, Pt, Au)

The title compounds were investigated by magnetic susceptibility measurements and Eu-151 Mossbauer spectroscopy. EuZnIn and EuPtIn show Curie-Weiss behavior above 60 K with experimental magnetic moments of 7.80(5) and 8.0(1) mu(B)/Eu, respectively, indicating divalent europium. The zinc compound orders antiferromagnetically at T-N = 8.0(5) K and no field induced transition is observed. EuPtIn orders antiferromagnetically in small external fields at 16.0(5) K and two metamagnetic transitions are detected at the critical field strengths B-C1 = 1.1(1) T and B-C2 = 2.6(2) T. At 5 K the saturation magnetic moment amounts to 7.0(1) mu(B)/Eu, suggesting a full parallel spin alignment. EuPdIn and EuAuIn order antiferromagnetically at 13.0(5) and 21.0(5) K in low external magnetic fields, respectively. The four compounds are metallic conductors. The Mossbauer measurements of the EuTIn compounds show (EU)-E-151 isomer shifts typical of divalent europium. The isomer shifts are found to be linearly correlated with the closest Eu-Eu distance in the structure. Based on the Mossbauer data the onset of magnetic order is observed at T-N(EuZnIn) = 9.5(5) K, T-N(EuPdIn) 15.5(5) K, T-N(EuAuIn) = 20.0(5) K, and T-N(EuPtIn) = 20.0(5) K, respectively. The magnetically split spectrum of EuZnIn reveals evidence of Eu site inequivalence. (C) 1998 Academic Press.