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

The crystal growth and optical and magnetic spectroscopies of perovskite ph ase, strontium lanthanium aluminate (SrLaAlO4) doped with trivalent erbium ape reported. Electron paramagnetic resonance of SrLaAlO4:1% Er3+ identifie s two distinct Er3+ ion centers in this material: a tetragonal (C-4v) symme try 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 s ymmetry 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 selecti ve excitation, a total of 40 energy levels and their irreducible representa tion symmetry labels have been determined for the C-4u symmetry center, whi le 22 energy levels have been determined for a minor center. A C-4v symmetr y, crystal-field parametrization for the dominant center yields optimized p arameters consistent with proposed structural models. The g tensors of the ground-state Kramers doublets, calculated from the C-4v center wave functio ns, are in good agreement with the measured g values.