【摘 要】
：
Novel scheelite structures of Li2Ca(WO4)2,Li2Ca2(WO4)(SiO4),and LiCa2(WO4)(PO4)fluorescent materials were successfully prepared using a high-temperature solid-phase process.The compounds were characterized by X-ray diffraction and energy dispersive spectr
【机 构】
：
School of Science,China University of Geosciences (Beijing),Beijing 100083,China;Beijing Key Laborat
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Novel scheelite structures of Li2Ca(WO4)2,Li2Ca2(WO4)(SiO4),and LiCa2(WO4)(PO4)fluorescent materials were successfully prepared using a high-temperature solid-phase process.The compounds were characterized by X-ray diffraction and energy dispersive spectroscopy.The tests revealed that the substitution of[WO4]2 by[SiO4]4-or[PO4]3 tetrahedron in tungstate had no significant influence on the crystal structure of the Li2Ca(WO4)2.When Dy3+ ions were introduced as an activator at an optimum doping concentration of 0.08 mol％,all of the as-prepared phosphors generated yellow light emissions,and the emission peak was located close to 576 nm.Replacing[WO4]2-with[SiO4]4-or[PO4]3-tetrahedron significantly increased the luminescence of the Li2Ca(WO4)2 phosphors.Among them,the LiCa2(WO4)(PO4)∶0.08Dy3+ phosphor had the best luminescence properties,decay life (r =0.049 ms),and thermal stability (87.8％).In addition,the as-prepared yellow Li2Ca(WO4)2∶0.08Dy3+,Li2Ca2(WO4)(SiO4)∶0.08Dy3+,and LiCa2(WO4)(PO4)∶0.08Dy3+phosphor can be used to fabricate white light emitting diode (LED) devices.
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