Magnetic hyperfine interactions in the Zintl phase EuZnSn

Abstract

Magnetic susceptibility, ¹¹⁹ Sn and ¹⁵¹ Eu Mössbauer effect measurements are reported for the Zintl phase EuZnSn which crystallizes with the TiNiSi-type structure. The stannide shows Curie–Weiss behaviour above 40 K with an experimental magnetic moment of µ _exp =7.88(5) µ _B /Eu, close to that of the free Eu ²⁺ ion of µ _eff =7.94 µ _B . At 20.5(2) K a magnetic phase transition to the antiferromagnetic state is observed in the temperature dependence of the inverse susceptibility at a magnetic flux density of 0.01 T. Magnetization measurements at 5 K indicate metamagnetism with a saturation magnetic moment of 6.80(5) µ _B /Eu and a critical field of 0.7(1) T. ¹⁵¹ Eu Mössbauer measurements show an isomer shift δ=-10.9 mm s ^-1 against EuF ₃ , as is typically observed for divalent europium. While onset of magnetic ordering is evident at T ₀ =26.5(5) K, full magnetic order is detected near 15 K. ¹¹⁹ Sn Mössbauer spectra show a large transferred magnetic field of 12.8 T at 4.2 K. The temperature dependence of this field is closely correlated with the internal magnetic field measured at the ¹⁵¹ Eu site (23.4 T at 4.2 K).