Synthesis\nand Spectroscopic Properties\nof Monoclinic α‑Eu₂(MoO₄)₃

Abstract

The\nmicrocrystals of monoclinic europium molybdate, α-Eu₂(MoO₄)₃, have been fabricated by solid-state\nsynthesis at <i>T</i> = 753–1273 K for 300 h. The\ncrystal structure of α-Eu₂(MoO₄)₃ has been refined by the Rietveld method and was found to belong\nto the space group <i>C</i>2/<i>c</i> with unit\ncell parameters <i>a</i> = 7.5576(1), <i>b</i> = 11.4709(2), <i>c</i> = 11.5158(2) Å, and β\n= 109.278(1)° (<i>R</i>_B = 3.39%). About\n40 narrow Raman lines have been observed in the Raman spectrum of\nthe α-Eu₂(MoO₄)₃ powder sample.\nThe luminescence spectra of α-Eu₂(MoO₄)₃ under excitation at 355 and 457.9 nm reveal domination\nof induced electric dipole transition ⁵D₀ → ⁷F₂ and the presence of ultranarrow lines at ⁵D₀ → ⁷F₀ and ⁵D₁ → ⁷F₀ transitions.