Optical spectroscopy and crystal-field analysis of YAl₃(BO₃)₄single crystals doped with dysprosium

YAl3 (BO3)4 crystals doped with Dy3+ were grown from a potassium trimolybdate flux. Their absorption and visible emission spectra and decay curves were measured at temperatures ranging from 10 to 298 K. The complete energy level scheme has been deduced from the low temperature measurements and reproduced by theoretical calculations based on a parametric Hamiltonian including coulombic, spin–orbit and crystal-field terms. The Judd–Ofelt parametrization scheme has been applied to the analysis of the room temperature absorption spectra. The calculated radiative lifetime of the 4F 9/2 state is 344 μs; this value is reasonably consistent with the experimental data.