Flux growth, structural studies and spectroscopy of K_2NdNb_5O_(15) and Nd:K_2LaNb_5O_(15) crystals

摘要

Single crystals of K_2NdNb_5O_(15) (KNdN) and Nd~(3+)-doped K_2LaNb_5O_(15) (Nd:KLN) were grown by means of the flux growth technique. X-ray diffraction studies indicate that they belong to the tetragonal tungsten-bronze niobates family. The 10 and 298 K absorption and emission spectra and the luminescence decay curves were measured and discussed in the light of the structural properties. The room temperature absorption spectra were analyzed in the framework of the Judd-Ofelt Theory in order to obtain information about the probabilities of the radiative processes. The calculated lifetimes have been compared with the experimental decay times in order to estimate the efficiencies of the non-radiative processes in both crystals.