Popis: |
Two different Cr3+ crystal-field sites in the elpasolite Cs2NaGaF6 were investigated by excitation and emission spectroscopy at 4.2, 77 and 300 K. The zero-phonon lines of the 2E→4A2 transition are clearly observed on time-resolved emission spectra and associated with each type of site by high-resolution emission measurements. The different fluorescence lifetimes at 4.2 K confirm the identification of the sites. The crystal-field parameter, Dq, and Racah parameters, B and C, are determined, and we establish an intermediate crystal-field situation for both Cr3+ centers. |