High pressure magnetic diffraction studies on CePtSi2

CePtSi₂ shows pressure induced superconductivity with a maximum transition temperature of 0.14 K between 1.4 and 2.1 GPa. Here we present high pressure magnetic neutron diffraction studies on CePtSi₂ using polycrystalline and single-crystal samples. We determined magnetic structure at ambient pressure to be a spin-density-wave structure with magnetic propagation vector of (0.32,0,0.11) and averaged ordered moment of 0.45(5)µ_B. Using high pressure neutron diffraction, we investigated pressure dependence of the magnetic propagation vector and the moment. Our results provide insight on the primary role in the superconducting pairing mechanism of CePtSi_2.