Polarized laser selective excitation and electron paramagnetic resonance of Er3+ centers in SrLaAlO4 crystals

The crystal growth and optical and magnetic spectroscopies of perovskite phase, strontium lanthanium aluminate (SrLaAlO4) doped with trivalent erbium ape reported. Electron paramagnetic resonance of SrLaAlO4:1% Er3+ identifies two distinct Er3+ ion centers in this material: a tetragonal (C-4v) symmetry center with spin Hamiltonian parameters of g parallel to = 2.7 +/- 0.05 and g perpendicular to = 8.5 +/- 0.05 and a minor center of orthorhombic symmetry having g(x) = 9.4 +/- 0.05, g(y) = 6.8 +/- 0.05, and g(z) = 2.3 +/- 0.05. From a combination of optical absorption and polarized laser selective excitation, a total of 40 energy levels and their irreducible representation symmetry labels have been determined for the C-4u symmetry center, while 22 energy levels have been determined for a minor center. A C-4v symmetry, crystal-field parametrization for the dominant center yields optimized parameters consistent with proposed structural models. The g tensors of the ground-state Kramers doublets, calculated from the C-4v center wave functions, are in good agreement with the measured g values.