Crystal structures and comparisons of potassium rare-earth molybdates KRE(MoO4)2 (RE = Tb, Dy, Ho, Er, Yb, and Lu)

Six potassium rare-earth molybdates KRE(MoO4)2 (RE = Tb, Dy, Ho, Er, Yb, and Lu) were synthesized by flux-assisted growth in K2Mo3O10. The crystal structures were determined using single-crystal X-ray diffraction data. The synthesized molybdates crystallize with the orthorhombic Pbcn space group (No. 60). Trendlines for unit-cell parameters were calculated using data from the current study. The unit-cell parameters a and c increase linearly whereas b decreases with larger RE cations, based on crystal radii. The unit-cell volumes increase linearly and the densities decrease linearly with larger RE cations. The average distances between the RE cations and the nearest O atoms increase with larger cations whereas the average distances of Mo—O and K—O do not show specific trends.

Syntheses, crystal structures and photoluminescence properties of two rare-earth molybdates CsLn(MoO4)2 (Ln=Eu, Tb)

Single crystals of two cesium rare-earth molybdates CsLn(MoO4)2(Ln=Eu, Tb) have been prepared using the high temperature molten salt (flux) method. Single-crystal X-ray diffraction analyses reveal that they crystallize in the orthorhombic space groupPccm(No. 49) and features a 2D layer structure that is composed of [Ln(MoO4)2]∞and [Cs]∞layers. Under near-UV light excitation, emission spectrum of CsEu(MoO4)2consists of several sharp lines due to the characteristic electronic transitions of Eu3+ions, whereas CsTb(MoO4)2exhibits characteristic green emission of Tb3+ions.