LOW-ENERGY-ELECTRON ENERGY-LOSS SPECTRA OF TRANSITION-METAL HALIDES

Low-energy electron energy loss spectra of transition metal halides MnBr2, MnF2 and FeF3 are measured for primary energies 20 to 400 V. For Mn halides, there are loss peaks which are thought to be due to the forbidden d-d transitions in Mn++ ions. The intensities of these loss peaks are primary energy dependent and decrease with the increase of the incident energy. As to FeF3, intensities of loss peaks are also incident energy dependent, but the dependence is different among each loss peak. As to the origin of the primary energy dependent losses, it is thought that the mixing of ligand halide p-orbitals with the d-orbitals of central metal ions is essential.