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

The microcrystals of monoclinic europium molybdate, α-Eu 2 (MoO 4 ) 3, have been fabricated by solid-state synthesis at T = 753–1273 K for 300 h. The crystal structure of α-Eu 2 (MoO 4 ) 3 has been refined by the Rietveld method and was found to belong to the space group C 2/ c with unit cell parameters a = 7.5576(1), b = 11.4709(2), c = 11.5158(2) Å, and β = 109.278(1)° ( R B = 3.39%). About 40 narrow Raman lines have been observed in the Raman spectrum of the α-Eu 2 (MoO 4 ) 3 powder sample. The luminescence spectra of α-Eu 2 (MoO 4 ) 3 under excitation at 355 and 457.9 nm reveal domination of induced electric dipole transition 5 D 0 → 7 F 2 and the presence of ultranarrow lines at 5 D 0 → 7 F 0 and 5 D 1 → 7 F 0 transitions.