Near-infrared emission form MnO42- in various host lattices

We have doped MnO42- into the host lattices K(2)MO(4) (M = S, Cr, Se), Cs2SO4 and BaMO(4) (M = S, Cr, Se, Mo). Broadband spontaneous emission between 11000 and 7000 cm(-1) is observed in all crystals upon visible or near-infrared photoexcitation. The Mn6+ emission persists up to room temperature with an estimated quantum efficiency of 20% in BaSO4:Mn. A correlation is established between the temperature quenching behaviour and the size of the host ion M(6+) for which Mn6+ substitutes: the quenching increases with increasing radius of M(6+).