Magnetic Properties of NpPt and PuPt

Abstract
NpPt was found t o be antiferromagnetic below 27 K; PuPt ferromagnetic (or perhaps ferrimagnetic) below 19 K and antiferromagnetic between 19 and 44 K. The apparent ferromagnetic saturation moment of PuPt is ≈ 0. 22 μB per Pu atom. The transition from anti‐ferromagnetism t o ferromagnetism in PuPt is moderately sensitive t o applied field, the overall cooperative magnetic behavior of the compound being qualitatively similar to that of the heavy rare earth metals.