Synthesis, photoluminescence properties and thermal investigation by TG-MS of RE(DAS)3•xH2O (RE = Eu3+, Tb3+)

Rare earth (III) diphenyl-4-amine sulfonates (RE(DAS)(3)center dot xH(2)O, RE = Eu3+, Tb3+) phosphors were synthesized by precursor method from barium diphenyl-4-amine sulfonate and rare earth sulfates. FTIR, TG/DSC coupled to mass spectrometry (TG/DSC/MS), X-ray powder diffraction (XPD), scanning electron microscopy (SEM) and photoluminescence (PL) spectroscopy were utilized to structurally and morphologically characterize the samples. Thermal decomposition of Eu(DAS)(3)center dot 7H(2)O and Tb(DAS)(3)center dot 2H(2)O at 973 K under dynamic air atmosphere results in crystalline Eu2O2SO4 and Tb2O2SO4 materials, respectively. Accordingly, MS spectra reveal the liberation of thermal decomposition products of precursors, largely as CO2, NO2 and SO2 gases. The diphenyl-4-amine sulfonate (DAS) ligand demonstrats a good stabilizing property for Eu3+ and Tb3+ ions. The Eu(DAS)(3)center dot 7H(2)O and Tb(DAS)(3)center dot 2H(2)O compounds display efficient red and green emissions, under UV excitation, arising from the D-5(0) -> F-7(J) (J = 0-4) and D-5(4) -> F-7(J) (J = 0-6) transitions of the Eu3+ and Tb3+ ions, respectively. Published by Elsevier B.V. on behalf of Chinese Society of Rare Earths.