Electronic Structure of the Americium Monopnictides: Ab Initio Calculations and Photoemission Experiments

Abstract

The americium monopnictides are interesting materials. One of the reasons is that americium is the first actinide element located on the right-hand side of the 5f delocalization-localization transition, i.e., the intriguing retraction of the 5f states from bonding which occurs between plutonium and americium. The americium side of the story has recently begun to be explored: Pressure experiments were applied to investigate the possibility of driving the Am 5f electrons towards delocalization [1]. Another route towards delocalization could in principle be through hybridization of the 5f¿s with ligand orbitals. This line of research has not yet been pursued, mainly because so far only a few Am compounds have been synthesized. Among these are the Am monopnictides, which crystallize in the cubic rocksalt structure and were found to be temperature independent paramagnets [2]. A theoretical study was recently devoted to the electronic structure of the Am monopnictides. Employing the self-interaction corrected, local spin-density approximation (SIC-LSDA) approach, Petit et al. [3] predicted the Am monopnictides to be metallic compounds, having a huge 5f partial density of states (DOS) in the immediate vicinity of the Fermi level.