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

Abstract Single crystals of two cesium rare-earth molybdates CsLn(MoO 4 ) 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 group Pccm (No. 49) and features a 2D layer structure that is composed of [Ln(MoO 4 ) 2 ] ∞ and [Cs] ∞ layers. Under near-UV light excitation, emission spectrum of CsEu(MoO 4 ) 2 consists of several sharp lines due to the characteristic electronic transitions of Eu 3+ ions, whereas CsTb(MoO 4 ) 2 exhibits characteristic green emission of Tb 3+ ions.