Transition intensity analysis and emission properties of Eu3+: Bi2ZnOB2O6 acentric biaxial single crystal

Marcin Piotr Kaczkan , Marcin Kowalczyk , Sławomir Szostak , Andrzej Majchrowski , Michał Malinowski

Abstract

Optical absorption, excitation and emission spectra of trivalent europium (Eu3+) ions in Bi2ZnOB2O6 nonlinear single crystal obtained by the Kyropoulos method were investigated. Strong, orange-red emissions of Eu3+ centered at 592 and 615 nm originate mainly from the 5D0 →7F1 and 7F2 transitions, respectively. Judd-Ofelt intensity parameters for f-f transitions were derived from the room temperature (300 K) emission spectra and were used to calculate the radiative transition rates (AR), lifetimes (τR) and branching ratios β for 5D0 excited state of Eu3+. The calculated values of τR and β were compared with the measured values for 5D0 level. The 5D0 fluorescence decay in 0.5 %Eu3+:Bi2ZnOB2O6 was exponential with time constant of 1.1 ms at room temperature. The stimulated emission cross-sections σ were also evaluated for the 5D0 → 7FJ transitions for the first time in this system. We also report on laser site selective spectroscopy of a Eu3+: Bi2ZnOB2O6 confirming the Eu3+ distribution into two sites. The site assignments of Eu3+ ions were discussed on the base of both optical spectroscopy results and structural analysis.