X-ray absorption spectra of the spinel LiCu 0.5Mn 1.5O 4

Abstract

X-ray absorption spectra of the spinel LiCu 0.5Mn 1.5O 4 were recorded at the Cu K and L 3, Mn K and L 3, and O K edge. The spectra are aligned on a common energy scale with the aim to establish an experimental picture of the conduction band structure. The fine structures observed a few electron volts around the absorption thresholds are discussed in terms of hybridisation of cation and anion orbitals. Emphasis is put on the identification of spectral features correlated with the presence of lithium on the tetrahedral sites of the spinel structure. The consequences of lithium insertion/extraction on the intensities of these spectral structures are discussed. Previous studies by X-ray absorption spectroscopy of lithium insertion/extraction in various spinels are found to agree with our expectations.