Structural Distortion and Magnetic Order in the Intermetallic ${\hbox {Eu}}_{3}{\hbox {Ir}}_{4}{\hbox {Sn}}_{13}$ Compound

In this work, we have investigated the low temperature structural distortion and magnetic properties of the Eu₃Ir₄Sn₁₃ Remeika cubic phase compound using X-ray powder diffraction (XRD), X-ray resonant magnetic scattering (XRMS) and neutron diffraction. X-ray scattering revealed that the peak observed in electrical resistivity and heat capacity measurements is related to a structural distortion at T*=57.1 K. This crystallographic distortion characterized by the arising of a propagation vector q^→=(0,(1/2),(1/2)) is due to a displacement of the Sn ions at the Sn1Sn2₁₂ polyhedron. In addition, the neutron diffraction experiments performed on a single crystal of Eu₃Ir₄Sn₁₃ exhibit an antiferromagnetic coupling below T_N=10.1 K where we observe a commensurate magnetic propagation vector τ^→=(0,(1/2),(1/2)) identical to the one observed for the structural distortion.