Experimental Stark Levels Research Articles

Analysis of the optical spectra of trivalent holmium in yttrium scandium gallium garnet

The absorption spectrum of Ho3+ ions in yttrium scandium gallium garnet (Ho3+:YSGG) is reported at 4 K between 1.93 and 0.28 μm. Laser excitation spectra and laser-excited fluorescence spectra from Ho3+(4f10)2S+1LJ multiplet manifolds 5F4, 5S2, and 5F3 to the ground-state manifold 5I8 were obtained at 4, 8, and 70 K. Unresolved emission is observed from Ho3+ ions in slightly disturbed cation (Y3+) sites along with emission coming from Ho3+ ions occupying the regular cation (Y3+) sites having D2 symmetry. Temperature-dependent transitions (hot bands) observed in absorption at 8 and 70 K establish experimental crystal-field split (Stark) levels in 24 excited manifolds and the seven lowest energy Stark levels in 5I8 (Z1=0, Z2=6, Z3=17, Z4=29, Z5=87, Z6=95, and Z7=102, all in cm−1). An algorithm is used to establish D2 symmetry labels Γ1, Γ2, Γ3, or Γ4 of individual experimental Stark levels. These levels are compared with results obtained from a calculation in which a parameterized Hamiltonian was diagonalized within the 50 lowest multiplet manifolds of Ho3+(4f10). Comparison between 157 experimental Stark levels and the corresponding predicted levels out of a total of 486 calculated levels yields a root-mean-square deviation of 5 cm−1.

Energy levels and crystal quantum states of trivalent holmium in yttrium aluminum garnet

Absorption spectra of Ho3+ ions in yttrium aluminum garnet (Ho3+:YAG) are reported between 2.16 and 0.23 μm at various temperatures between 4 K and room temperature. Laser-excited excitation spectra and emission spectra from the 5F4 and 5S2 multiplet manifolds to the ground state manifold 5I8 were obtained at 4, 20, and 55 K. The majority of Ho3+ ions substitute for Y3+ ions in sites of D2 point-group symmetry in the lattice. Over 1000 temperature-dependent transitions (hot bands) establish 280 experimental Stark levels of the 4 f 10(2S+1LJ) multiplet manifolds. Symmetry labels Γ1, Γ2, Γ3, or Γ4, appropriate to D2 symmetry, have been assigned to Stark levels up to 43 000 cm−1. Experimental levels are compared with results obtained from a theoretical calculation. The model Hamiltonian includes Coulombic, spin-orbit, and interconfiguration interaction terms for the 4 f 10 atomic configuration of Ho3+ and crystal-field terms in D2 symmetry. The Hamiltonian was diagonalized within the 50 lowest 2S+1LJ manifolds in a LSJMJ basis set that includes 486 calculated levels. Comparison between 151 experimental Stark levels and the corresponding levels of the lowest 199 calculated levels yields an rms deviation of 4.3 cm−1.

Spectroscopic analysis of Er 3+(4f 11) in Y 3Sc 2Al 3O 12

Absorption spectra of Er 3+ (4f 11) in single crystal Y 3Sc 2Al 3O 12 (YSAG) are reported between 1.54 and 0.20 μm at 15 and 90 K. Laser-excited emission and excitation spectra obtained at 77 K are presented involving transitions between the 4S 3 2 manifold and the 4I 15 2 ground state manifold and between the 2P 3 2 manifold and the 4I 15 2 , 4I 13 2 , 4I 11 2 , and 4I 9 2 manifolds. The individual Stark levels of twenty-nine 2 S+1 L j manifolds up to 43700 cm −1 were analyzed. Levels above 28000 cm −1 are analyzed for the first time in a garnet crystal. Temperature-dependent spectra were used to establish 120 Stark levels. The spectra indicate that most Er 3+ ions substitute for Y 3+ ions in dodecahedral sites in the lattice. Spectroscopic evidence for Er 3+ ions in octahedral sites is found in the spectrum of the 4I 13 2 manifold. The 74 experimental Stark levels lowest in energy are compared with the results of a crystal-field splitting calculation. The Hamiltonian used includes Coulombic, spin-orbit, and interconfigurational interaction terms for the 4f 11 atomic configuration of Er 3+ and crystal-field terms appropriate for D 2 symmetry. The entire Hamiltonian was diagonalized within a 4f 11 SLJM J basis set which included the lowest fifteen 2 S+1 Lj manifolds. The rms deviation between 74 calculated and experimental Stark levels was 8 cm −1.

Spectroscopic properties and paramagnetic susceptibility of Na 5Eu(MoO 4) 4 and Na 5Eu(WO 4) 4

Crystal field parameters were determined for the scheelite-type double molybdates (tungstates) of a rare earth and sodium, yielding a good simulation of the experimental Stark levels. The associated wavefunctions were applied to calculate the Van Vleck paramagnetism. The small discrepancy with the experimental temperature-dependent paramagnetic susceptibility is discussed.

Experimental and calculated energy levels of Sm2+:BaClF

New investigations on the optical properties of divalent samarium in barium chlorofluoride single crystals have been performed. As a result, an energy level diagram including 42 Stark components of the 7FJ and 5DJ multiplets of the 4f6 configuration has been deduced from the excitation and fluorescence spectra. Parameter optimizations involving combined spin–orbit and crystal-field interactions have been achieved from the experimental Stark levels of the 7F ground term. An interpretation of the fitted crystal-field parameters has been developed in the framework of an additive ligand-field model. The irreducible tensor method applied to the chain O3⊆C∞v⊆C4v⊆C2v is used throughout this paper.