Electron-phonon interaction in Tm3+, Ho3+, and Dy3+ doped BaY2F8 single crystals

High resolution Fourier transform spectroscopy is applied in a wide wave number range (500-24,000 cm−1) to investigate the electron-phonon interaction in Dy3+, Tm3+, and Ho3+ doped BaY2F8 single crystals. The shape, position, and width of the zero phonon (ZP) absorption lines induced by RE3+ ions are carefully analyzed in the 9-300 K range. The line shift and broadening are discussed in the framework of a two phonon Raman scattering model and the electron-phonon coupling constants are obtained as fitting parameters. The interaction between the RE3+ ion and the surrounding matrix is unveiled also by weak vibronic lines accompanying the ZP ones.