FERRATE(VI), A NOVEL NEAR-INFRARED LUMINOPHORE

Upon excitation with visible or near-infrared light, FeO42--doped K2CrO4 crystals show sharp-line luminescence at approximately 1.6-mu-m, which is only partially quenched at room temperature. The ferrate(VI) ion, which has been known for more than one century, is potentially important in the search for new near-infrared laser materials, in analogy to tetraoxo-coordinated Mn5+ and Cr4+ ions.