  We present the ab initio supported discovery of two new Pu based
intermetallic compounds, PuNiSn and PuPtSn. Using density functional theory,
the formation energies within the relevant ternary phase diagrams were
calculated to predict the stability of both compounds. Simultaneously, Pu-Ni-Sn
and Pu-Pt-Sn materials were arc-melted and subsequently characterized with
magnetization, specific heat, and resistivity measurements from 2-300 K.
Magnetization measurements show that PuNiSn and PuPtSn order
antiferromagnetically at TN = 11 K and TN = 15 K, respectively. Specific heat
measurements show an enhanced residual electronic specific heat that is
indicative of strong electron correlations. Resistivity measurements are
indicative of Kondo behavior for PuNiSn while crystal field effects may play a
role in the observed temperature dependence for PuPtSn.
