Electronic Spectrum and Antiferromagnetic A-B Interactions between Tetrahedral 3d5 and 3d5 or 3d3 Octahedral Cations in Oxidic Lithium Spinels

Abstract The compounds chosen to illustrate the interpretation of ligand field spectra of inorganic solids with A-B antiferromagnetic coupling between Fe 3+ tetrahedral and Fe 3+ or Cr 3+ octahedral cations belong to the Li 0.5 Fe x Ga 2.5- x O 4 and Li 0.5 (FeCr) x Ga 2.5-2 x O 4 systems. New features, such as the interpretation of the iron(III) electronic spectrum in ferrimagnetic spinels, the influence of the nature of the superexchange interactions of the pair excitation processes, and the growth of an electronic transition assigned to Cr 3+ + Fe 3+ → Cr 4+ + Fe 2+ intervalence charge transfer at 1.8 eV are reported in this study.