Potassium dihydrogen phosphate doped with organic complexes of rare-earth metals

We have examined conditions for the crystal growth of KDP doped with rare-earth (Ce, Sm, Gd, Yb) complexes with alizarin complexone. The complexes have different effects on KDP crystal growth and are selectively incorporated into the growth sectors of the crystals, which can be rationalized in terms of their structure and charge. In going from KDP solutions to crystals, the absorption bands of both the free ligand and its complexes with the rare-earth metals (482–510 nm) shift insignificantly. In contrast, the luminescence spectra of the complexes and ligand experience a bathochromic shift. The Stokes shift of the complexes in crystals is three to four times greater than that in solutions. The luminescence bands are centered at 598–625 nm.