SYNTHESIS, CHARACTERIZATION AND SPECTROSCOPY OF THE EUROPIUM-DOPED LANTHANUM TRIMETAPHOSPHATE

Orthorhombic modification of europium doped lanthanum trimetaphosphate has been prepared. The compound was obtained by precipitation of rare earth chloride solution with trimetaphosphoric acid. The characteriza tions were made using X-ray diffractometry, chemical analysis and infr ared spectroscopy. Excitation and emission spectra were recorded at li quid nitrogen and room temperatures. Assignments of the D-5(0) --> F-7 (J) (J = 0, 1, 2, 3, 4, 5) transitions were made and an unusual high D -5(0) --> F-7(4) transition intensity with six split lines has been ob served. Structural distortion of the crystal lattice may be caused by the Eu3+ ion inclusion. The simple overlap model was applied for the c alculation of the total splitting of the D-5(0) --> F-7(1) transition, the D-5(0) --> F-7(0) / D-5(0) -->F-7( )2 transition intensity ratio and the Omega(lambda) (lambda = 2.4) intensity parameters. Theoretical predictions showed to be in good accordance with the experimental dat a. (C) 1988 Elsevier Science S.A.