Raman scattering studies in the solid electrolytes of the RbAg4I5family

摘要: We have studied the dynamics of mobile ${\mathrm{Ag}}^{+}$ ions and their surrounding tetrahedral iodine cages in solid electrolytes $M{\mathrm{Ag}}_{4}{\mathrm{I}}_{5}$ ($M=\mathrm{Rb}, \mathrm{N}{\mathrm{H}}_{4}, \mathrm{K}$) by Raman scattering. Polarized spectra oriented single crystals been measured from melting point to second-order phase transition ${T}_{2}$ first-order ${T}_{1}$ for K${\mathrm{Ag}}_{4}$${\mathrm{I}}_{5}$. observed (i) a broad peak at 105 ${\mathrm{cm}}^{\ensuremath{-}1}$ mainly ${A}_{1}$ symmetry which is believed be due breathing modes crystalline ${\mathrm{I}}^{\ensuremath{-}}$ tetrahedra, (ii) shoulder near 20 nearly equal ${F}_{2}$ $E$ components little ${A}_{1}$, interpreted as being attempt vibrations silver ions, (iii) quasielastic has assigned diffusive (iv) 17 having symmetry, (v) three peaks frequencies 50, 27, $X$ ${\mathrm{cm}}^{\ensuremath{-}1}$, where $X=15, 17, \mathrm{and} 18.5$ $M=\mathrm{Rb}, K$, respectively. Except latter peak, are essentially identical different $M$, no new features appear below ${T}_{2}$.