Neutron scattering, magnetic, and transport properties of non-centrosymmetric UIrSi$_{\mathrm{3}}$.

Heavy-fermion superconductivity in the non-centrosymmetric crystal structure has drawn much attention [1]. It is argued that the order parameter contains not only a spin-singlet part, but also an admixture of a spin-triplet state. The compound UIrSi$_{\mathrm{3\thinspace }}$crystallizes in the non-centrosymmetric BaNiSn$_{\mathrm{3}}$ structure which is closely related to the well-known ThCr$_{\mathrm{2}}$Si$_{\mathrm{2}}$-type [2]. Preliminary study on polycrystalline UIrSi$_{\mathrm{3}}$ shows antiferromagnetic order below Neel temperature $T_{\mathrm{N}}=$42 K [2]. Its lanthanide analog CeIrSi$_{\mathrm{3}}$ shows heavy-fermion superconductivity under pressure [1]. Therefore, further investigation on UIrSi$_{\mathrm{3}}$ would be meaningful. We would like to present the results of our investigation on UIrSi$_{\mathrm{3\thinspace }}$by neutron scattering, magnetic, and transport measurement on poly and single crystals grown by Czochralski method in a tetra-arc-furnace. [1] Onuki \textit{et al}., J. Phys. Soc. Jpn. \textbf{77}, suppl. A 37 (2008). [2] Buffat \textit{et al.}, J. Mag. Mag. Mat. 62, 53 (1986).