Agradecimentos: This work was supported by CNPq (Brazil), CAPES (Brazil) and FAPESP (SP-Brazil) under Contract 2009/10264-0. Work at Argonne is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract DE-AC-02-06CH11357. The authors would like to thank the LNLS and the SINQ facilities for the technical support and the beam time Ver menos

Abstract: In this work, we have investigated the low temperature structural distortion and magnetic properties of the Eu 3 Ir 4 Sn 13 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 Sn1Sn2 12 polyhedron. In addition, the neutron diffraction experiments performed on a single crystal of Eu 3 Ir 4 Sn 13 exhibit an antiferromagnetic coupling below T N =10.1 K where we observe a commensurate magnetic propagation vector t ? =(0,(1/2),(1/2)) identical to the one observed for the structural distortion Ver menos