L₂,₃edges of tetrahedrally coordinated d⁰transition-metal oxyanions XO₄n-

The L 2,3 edges of compounds containing tetrahedrally coordinated, isoelectronic d 0 transition-metal oxyanions, TiO 4 4- , VO 4 3- , CrO 4 2- and MnO 4 - have been measured using electron energy-loss spectroscopy (EELS). The general shape of the electron energy-loss near-edge fine structure (ELNES) is found to be remarkably similar for these oxyanions and arises from the atomic multiplet spectrum of the d 0 transition-metal ion modified by the tetrahedral field due to the oxygen ligands. The observed structure is also discussed within the framework of molecular-orbital (MO) theory. The possibilities of using these spectra as fingerprints for d 0 transition-metal ions in tetrahedral coordination is discussed. The structure observed at the O K edges is also commented upon in the light of these findings.