Synthesis and Spectroscopic Properties of Monoclinic α-Eu2(MoO4)3

The microcrystals of monoclinic europium molybdate, alpha-Eu-2(MoO4)(3), have been fabricated by solid-state synthesis at T = 753-1273 K for 300 h. The crystal structure of alpha-Eu-2(MoO4)(3) has been refined by the Rietveld method and was found to belong to the space group C2/c with unit cell parameters a = 7.5576(1), b = 11.4709(2), c = 11.5158(2) angstrom, and beta = 109.278(1)degrees (R-B = 3.39%). About 40 narrow Raman lines have been observed in the Raman spectrum of the alpha-Eu-2(MoO4)(3) powder sample. The luminescence spectra of alpha-Eu-2(MoO4)(3) under excitation at 355 and 457.9 nm reveal domination of induced electric dipole transition D-5(0) -> F-7(2) and the presence of ultranarrow lines at D-5(0) -> F-7(0) and D-5(1) -> F-7(0) transitions.