Analysis of the fluorescence spectra on Kimuraite

Abstract

The fluorescence spectra and luminescent properties of Kimuraite [CaY₂(CO₃)₄·6H₂O, rhombic, Bizen-cho, Higashimatsuura, Saga pref.] were investigated by a three-dimensional contour-plot method. From the results, the strongly reddish-purple fluorescence of the mineral under ultraviolet light was found to depend on the following fluorescent rare-earth(III)ions. Eu(III), Tb(III), Dy(III), and Gd(III). These rare-earth(III)ions in the mineral showed many sharp excitation and emission bands. The bands of the luminescence of Kimuraite could be attributed to the f-f allowed transition of Eu(III): Ex. 395 nm (⁷F₆→⁵L₆)/Em. 615 nm (⁵D₀→⁷F₂); Tb(III): Ex. 380 nm (⁷F₆→⁵D₃)/Em. 545 nm (⁵D₄→⁷F₅); Gd(III): Ex. 275 nm (⁸S_7/2→ ⁶D_3/2)/Em. 312 nm (⁶P_7/2→⁸S_7/2);Dy(III): Ex. 352 nm/Em. 575 nm (⁴F_9/2→⁶H_13/2), respectively.