Magnetic structure determination of noncentrosymmetric Kondo lattice antiferromagnet CeIrSi3

CeIrSi3 belongs to the family of noncentrosymmetric heavy-fermion superconductors, which have attracted significant attention for their distinct unconventional superconducting ground state characterized by mixed spin-singlet and spin-triplet pairing symmetry. At ambient pressure, CeIrSi3 exhibits an antiferromagnetic (AFM) ordering at TN=5 K, and becomes superconducting upon suppressing AFM order by pressure with a superconducting Tc ≈ 1.6 K at a Pc=2.5 GPa. In order to understand the nature of 4f-electrons, hard or easy-axis ordering and their role in the superconductivity in CeIrSi3 a knowledge of its detailed magnetic structure is highly desired. Further, we want to test the position of CeIrSi3 on the Doniach phase whether it orders with hard or an easy axis. We therefore propose to carry out neutron diffraction measurements on CeIrSi3 using the WISH diffractometer.