Peculiarities of low-frequency excitation spectrum of CsDy1-xBix(MoO4)(2)

Low-frequency IR transmission spectra for a series of isostructural single crystals of CsDy1-xBix(MoO4)(2) (x=0, 0.05, 0.1, 0.2, 0.3, 0.5, and 0.7) ar e measured at low temperatures (T similar or equal to 6 K). It is found exp erimentally that absorption band broadening takes place in the Bi concentra tion range 0.2 less than or equal to x less than or equal to 0.6. The mecha nism which may result in absorption spectrum blurring are considered. (C) 1 999 American Institute of Physics. [S1063-777X(99)01112-3].