Spin–Flop and Metamagnetic Transition in Monoclinic Eu₄Bi₆Se₁₃

This study explores an investigation of the crystallographic, electronic, and magnetic properties of the europium-based bismuth selenide compound Eu₄Bi₆Se₁₃, with particular focus on its magnetic anisotropy. This compound adopts a monoclinic crystal structure classified under the <i>P</i>2₁/<i>m</i> space group (#11). It exhibits distinctive structural features, including substantial Eu-Se coordination numbers (6 and 8), Bi-Se ladders, and linear chains of Eu atoms that propagate along the <i>b</i>-axis. Electronic resistivity assessments indicate that Eu₄Bi₆Se₁₃ exhibits metallic behavior. As the magnetic field is oriented along the <i>b</i>-axis, magnetic characterization reveals uniaxial magnetic anisotropy, with metamagnetic transitions appearing at approximately 12 kOe and a lower field. In the field below 10 kOe, the spin-flop transition is observed with possible domain-induced hysteresis. This behavior supports the identification of metamagnetic features in field-dependent measurements attributable to the europium spins.