LUMINESCENCE PROPERTIES OF MN5+ IN A VARIETY OF HOST LATTICES - EFFECTS OF CHEMICAL AND STRUCTURAL VARIATION

The optical spectroscopic properties of Mn5+ doped into ten host lattices have been studied. The influence of both chemical variation [phosphates(V), arsenates(V), and vanadates(V)] and structural variation (spodiosites, apatites, and Li3PO4-type salts) on the luminescence properties is studied in detail. By varying the host lattice, the position of the sharp luminescence band can be varied from 8300 to 8960 cm(-1). Excited state splittings, luminescence lifetimes, and sideband intensities are correlated with the geometrical distortion of the MnO43- tetrahedron. In all the host lattices, the luminescence originates from the (1)E elicited state at all temperatures. It is essentially unquenched at room temperature in apatite and Li3PO4-type lattices, whereas in spodiosites up to 90% of the luminescence may be quenched at room temperature.