Optical spectroscopy of Cr4+-doped Ca2GeO4 and Mg2SiO4.

摘要: Polarized single crystal absorption spectra and luminescence of ${\mathrm{Cr}}^{4+}$-doped ${\mathrm{Ca}}_{2}$${\mathrm{GeO}}_{4}$ ${\mathrm{Mg}}_{2}$${\mathrm{SiO}}_{4}$ are presented discussed. The analyzed using the angular overlap model (AOM). agreement between experimental AOM-calculated energies ligand field states is satisfactory. parameters 10Dq B 8950 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ 540 for 10 100 560 ${\mathrm{Mg}}_{2}$${\mathrm{SiO}}_{4}$, respectively. $^{3}$${\mathit{A}}_{2}$${\ensuremath{\rightarrow}}^{1}$${\mathit{A}}_{1}$ transition appears as a Fano antiresonance in spectrum ${\mathrm{Mg}}_{2}$${\mathrm{SiO}}_{4}$. assigned to from an excited triplet state, which definitely not mixed with $^{1}$E contributions ${\mathrm{Ca}}_{2}$${\mathrm{GeO}}_{4}$. surprisingly sharp. Possible explanations much less quenched at room temperature than host. Finally, spectroscopic properties materials compared those other 3${\mathit{d}}^{2}$ ions tetroxo coordination. \textcopyright{} 1996 American Physical Society.