Electronic Structure and Surface Science of delta Plutonium

摘要

High resolution photoelectron spectroscopy (PES) studies were conducted on a δ-phase Plutonium sample cleaned by laser ablation and gas dosed with O_2 and H_2. The measurements were made with an instrument resolution of 60 meV and with the sample at 77 K. The PES data strongly support a model with Pu_2O_3 growth on the metal and then PuO_2 growth on the Pu_2O_3 layer at this temperature. In vacuum, the PuO_2 reduces to Pu_2O_3 at room temperature with a pressure of 6 x 10~(-11) Torr. In the case of H_2 dosing the hydrogen appears to penetrate the surface and disrupt the valence band as evidenced by a drop in intensity of the peak at E_F which is not accompanied by a drop in the main 5f manifold at ～2eV.