PRODUCTION AND INVESTIGATION OF CRYSTALS OF MIXED HALOGENIDES FOR LOW-PHONON LASER MATRICES
This work is devoted to the growth, investigation of the crystal structure and spectroscopic properties of crystals of mixed halides (K,Rb)Pb<sub>2</sub>Cl<sub>5</sub> and K<sub>0.5</sub>Rb<sub>0.5</sub>Pb<sub>2</sub>Br<sub>5</sub> doped with ions of rare earth elements, in comparison with ternary analogues. These materials are of interest as crystalline low-phonon laser matrices for efficient conversion of coherent radiation in the IR range. (K,Rb)Pb<sub>2</sub>Cl<sub>5</sub> and K<sub>0.5</sub>Rb<sub>0.5</sub>Pb<sub>2</sub>Br<sub>5</sub> crystals were grown by the Bridgman method (vertical version). Doped crystals of K<sub>0.5</sub>Rb<sub>0.5</sub>Pb<sub>2</sub>Br<sub>5</sub>:Er<sup>3+</sup> composition were obtained for the first time. The structure and spectroscopic characteristics of the grown crystals were investigated. It is shown that the bromide crystals are transparent up to 30 microns. In the doped matrix of K<sub>0.5</sub>Rb<sub>0.5</sub>Pb<sub>2</sub>Br<sub>5</sub>:Er<sup>3+</sup> rare earth ions exhibit an intense absorption peak, which indicates a sufficiently high incorporation coefficient of a rare-earth ion into the structure of a mixed crystal. Thus, K<sub>0.5</sub>Rb<sub>0.5</sub>Pb<sub>2</sub>Br<sub>5</sub>:Er<sup>3+</sup> crystals can be considered as a promising crystalline material for laser radiation generation, however, studies of their functional properties should be continued.