Magnetic properties of ferromagnetic Pu2Pt3Si5

• A new plutonium based intermetallic obtained as single crystals with the U2Co3Si5-type orthorhombic Iabm structure (72).
• Ferromagnetic behavior at 58 K with saturated moment σsat ∼0.32 μB/Pu and effective moment μeff ∼0.74 μB.
• Localized features with very low linear Sommerfeld coefficient γe ∼2 mJ mol−1 K−2/Pu.

The structural, magnetic, and thermodynamic properties of a new plutonium based compound, Pu2Pt3Si5, are reported. Single crystals produced by a Sn-flux technique have been analyzed showing a ferromagnetic behavior at 58 K. Pu2Pt3Si5 crystallizes in the U2Co3Si5-type orthorhombic Iabm structure (s.g. 72) with atomic parameters a = 9.9226(2) Å, b = 11.4436(2) Å and c = 6.0148(1) Å. The effective (μeff ∼0.74 μB/Pu) and saturated (σsat ∼0.34 μB/Pu) moments as well as the Sommerfeld coefficient (γe ∼2 mJ mol−1 K−2/Pu) could point towards 5f localization in this material.