Plutonium and Quantum Criticlity

The unusual properties of elemental plutonium have long been a puzzle. It has been suggested that these properties may be related to quantum criticality [G. Chapline, J. L. Smith LA Sci 26 (2000) 1]. In this talk we will describe some experimental observations on rare earth and actinide materials which suggest that there are pairing correlations in all f-electron metals, and that the anomalous properties of the elemental actinides in the vicinity of Np/Pu/Am,even at elevated temperatures, is associated with a critical point in the variation of the density of paired electrons with atomic number.