151Eu and 121Sb 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 Sb2Se3.