title: Li/Ag ratio dependent structure and upconversion photoluminescence of Li(x)Ag(1-x)Yb(0.99)(MoO4)(2):0.01Er(3+) phosphors.
abstract: A series of double molybdate scheelite-type phosphors LixAg1-xYb0.99(MoO4)2:0.01Er(3+) (x = 0, 0.1, 0.3, 0.5, 0.7, 0.9, 1.0) were synthesized by the solid state reaction method, and their crystal structures and upconversion (UC) luminescence properties were investigated in detail. The phase structure evolution of this series samples was discussed and the selected Li0.5Ag0.5Yb0.99(MoO4)2:0.01Er(3+) was analyzed based on the Rietveld refinement. The UC emission properties and the related UC mechanism were also studied. With an increasing Li/Ag ratio in this host, the UC emission intensities of LixAg1-xYb0.99(MoO4)2:0.01Er(3+) increased obviously, and the enhancement could be attributed to the coupling effect and the nonradiative transition between two energy levels of LixAg1-xYb(MoO4)2 matrices and the activator Er(3+), which have also been analyzed based on the results of the ultraviolet-visible diffuse reflection spectroscopy (UV-vis DRS) and Raman spectroscopy.
authors.affiliation: School of Materials Sciences and Technology, China University of Geosciences, Beijing 100083, China.
authors.forename: Fangrui
authors.initials: F
authors.lastname: Cheng
authors.forename: Zhiguo
authors.initials: Z
authors.lastname: Xia
authors.forename: Xiping
authors.initials: X
authors.lastname: Jing
authors.forename: Ziyuan
authors.initials: Z
authors.lastname: Wang
mesh_terms: D004871:Erbium / Q000737:chemistry*; D008094:Lithium / Q000737:chemistry*; D008163:Luminescent Measurements; D008982:Molybdenum / Q000737:chemistry*; D011789:Quantum Theory; D012834:Silver / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013059:Spectrum Analysis, Raman; D013816:Thermodynamics; D015018:Ytterbium / Q000737:chemistry*
chemical_list: C044659:molybdate; D012834:Silver; D004871:Erbium; D008982:Molybdenum; D008094:Lithium; D015018:Ytterbium