Eu and Sb Mössbauer spectroscopy of EuSbSe3 and EuBiSe3

¹⁵¹Eu and ¹²¹Sb Mössbauer spectroscopy of EuSbSe₃ and EuBiSe₃ were measured at different temperatures. The presence of divalent europium and trivalent antimony were confirmed. The largely negative values of the isomer shift in ¹⁵¹Eu spectrum show highly ionic bonding within these two compounds. Both of them show magnetic hyperfine field splitting at 4.2 K, which indicates a change in the orientation of the EFG principal axis with respect to the magnetic hyperfine field direction. EuSbSe₃ has slightly smaller electron density at the antimony nuclei, compared to Sb₂Se_3.