Metamagnetic behaviour of Nd3Pt23Si11

In the course of studying the R3Pt23Si11 series (R=rare earth), we have recently synthesized Nd3Pt23Si11. It crystallizes in a face-centered cubic structure (Fm-3m space group) with a lattice parameter of 16.8493(4) Å at room temperature. Heat capacity and magnetic measurements show the existence of a magnetic transition at 1.6 K. Measurements of the susceptibility and magnetization down to 95 mK reveal metamagnetic behavior confirming antiferromagnetic ordering. Powder neutron diffraction experiments show that the magnetic propagation vector is k=[000] and that the 6 neodymium moments in the unit cell are antiferromagnetically coupled in pairs.