Electronic spectrum of the manganate(V) ion in different host lattices

Abstract

A comparative account is given of the 4.2 K linearly polarised absorption spectra of Sr₅(PO₄)₃ Cl and Ca₂PO₄Cl crystals containing MnO^3–₄, with emphasis on the differing site-group perturbations. With the inclusion of a previously undetected shoulder at 11 500 cm^–1 in the Ca₂PO₄Cl case, it is possible to account for the energies and polarisations of all the bands using similar values of Δ and B(respectively 11 000–11 500 and 500–550 cm^–1) but different parameters describing the tetragonal and trigonal site perturbations. It is confirmed that all bands in the visible are of ligand-field type and that the lowest charge-transfer band is at 32 000–33 000 cm^–1.