PNNL

Abstract

We investigate the local electronic structure of a-Li3N by the combination of nonresonant inelastic x-ray scattering measurements and three independent ab initio theoretical treatments. Experimental determination of the local final density of states projected onto an orbital angular momentum basis (l-DOS) for Li 1s initial states finds strong similarities in the s- and p-DOS throughout the near-edge region, which we attribute to the 3-fold rotational symmetry about Li sites in the Li2N sheets of a-Li3N. We also find a significant correspondence between the near-edge spectra for the Li 1s and N 1s contributions to the NRIXS signal. This is unexpected, as such behavior is typically associated with covalent materials whereas a-Li3N is strongly ionic. We explain that such similarity in the DOS at different sites in either ionic or covalent systems may occur when the core-hole lifetimes are very long, so that the lifetime of the photoelectron is the dominant factor in cutting off high-order multiple scattering in the near-edge regime. This work was supported by the U.S. Department of Energy's Office of Basic Energy Sciences. The Pacific Northwest National Laboratory is operated by Battelle for DOE.