Solid-state syntheses of rare-earth-doped Sr_(1-x)Ln _(2x/3)MgP_2O_7 (Ln=Gd, Eu, Dy, Sm, Pr, and Nd; X=0.05) by metathesis reactions and their spectroscopic characterization

摘要

Rare-earth-doped strontium magnesium diphosphates of composition Sr _(1-x)Ln_(2x/3)MgP_2O_7 (Ln=Gd, Eu, Dy, Sm, Pr, and Nd; x=0.05) were prepared by metathesis reaction. These diphosphates were characterized by powder X-ray diffraction (XRD), energy dispersive spectra (EDS), and infrared spectroscopy. All these compounds were found to crystallize in monoclinic lattice with P2_1 space group. The compositions of all the samples were confirmed from their EDS spectra. The infrared spectra of all the samples were characterized by bands due to P_2O_7~(4-) units. The ~(31)P MAS-NMR of these compounds suggests the presence of two types of phosphorous ions in the lattice. The electron-spin resonance spectrum of Sr_(1-x)Gd_(2x/3)MgP_2O_7 (x=0.05) gave "U"-type spectrum due to the low symmetry of the Gd ~(3+) ion in the host lattice. The local symmetry of Eu~(3+), Dy~(3+), and Sm~(3+) in Sr_(1-x)Ln _(2x/3)MgP_2O_7 (Ln=Eu, Dy, and Sm; x=0.05) was obtained from their room-temperature luminescence spectra.