Crystal field parameters and energy level structure of the MnO43− tetroxo anion in Li3PO4, Ca2PO4Cl and Sr5(PO4)3Cl crystals

A comparative study concerning the electronic structure of the Mn5+ ion in the Li3PO4, Ca2PO4Cl, Sr5(PO4)3Cl host lattices has been carried out in the framework of the exchange charge model. The crystal field parameters have been evaluated using the structural data as the only input information. The 10 K absorption spectra of the investigated compounds have been measured in order to verify the correspondence between experimental and calculated energy levels. A systematic trend of the crystal field splitting of the most intense transitions has been evidenced and discussed by considering the symmetry properties of the coordination polyhedra around Mn5+.