Optical and EPR spectroscopy of Er3+ in lithium yttrium borate, Li6Y(BO3)3:Er single crystals

摘要

The energy levels of Er3+ ions have been determined in lithium yttrium borate (Li6Y(BO3)3) single crystalsudin a wide spectral range between 6000 and 40000 cm-1 together with an analysis of the ground state,udusing optical and EPR spectroscopy. The crystal field splittings of the 4I15/2 ground state and those ofudnearly all excited states up to the 4D7/2 manifold have been obtained at low temperature from luminescence (T = 5 K) and absorption (T = 9 K) measurements, respectively. The numbers of experimentally observed Stark sublevels agree well with those expected theoretically for Er3+ ions occupying a single low symmetry (C1) site. A full set of g- and 167Er hyperfine tensor parameters are presented for theudground state characterized by EPR; the measured Orbach-type spin-relaxation rates viz. the involvedudactivation energies correspond to the optically derived lowest excited sublevels.