Absorption intensity analysis and emission properties KEu(PO3)4 and KEuxY1-x(PO3)4 crystals

Abstract Optical absorption, excitation and emission spectra of Eu 3+ ions in stoichiometric KEu(PO 3 ) 4 and KEu x Y 1-x (PO 3 ) 4 crystals were investigated. Strong, red emissions of Eu 3+ centered at 617 and 700 nm originates mainly from the 5 D 0 → 7 F 2 + 7 F 4 transitions respectively. Judd-Ofelt intensity parameters for f-f transitions were derived from the emission spectra and also from the integrated absorption spectra. These parameters were used to calculate the radiative transition rates (A R ), lifetimes (τ R ) and branching ratios β for 5 D 0 excited state of Eu 3+ . The calculated values of τ R and β were compared with the measured values for 5 D 0 level. The 5 D 0 fluorescence decay time in pure KEu(PO 3 ) 4 was exponential and quite long, of 3.93 ms. The stimulated emission cross-sections σ were also evaluated for the 5 D 0 → 7 F J transitions for the first time in this system.