Elastic flexibility, fast-ion conduction, boson and floppy modes in AgPO3–AgI glasses

摘要: Raman scattering, IR reflectance and modulated-DSC measurements are performed on specifically prepared dry (AgI)x(AgPO3)1−x glasses over a wide range of compositions 0% 37.8% elastically flexible. optical elasticity power laws, trends in the nature glass transition endotherms, corroborate three elastic phase assignments. Ionic conductivities reveal step-like increase when become stress-free at x>xc(1) = 9.5% logarithmic conductivity (σ~(x−xc(2))μ) once they flexible x>xc(2) with law μ 1.78. The is consistent percolation 3D filamentary conduction pathways. Traces water doping lower Tg narrow reversibility window, can also completely collapse it. Ideas network flexibility promoting ion harmony unified approach Ingram et al (2008 J. Phys. Chem. B 112 859), who have emphasized similarity process compliance or relating to transport structural relaxation decoupled systems. Boson mode frequency scattering strength display thresholds that coincide two boundaries. In particular, boson increases almost linearly composition x, slope tracks floppy fraction as function mean coordination number r predicted by mean-field rigidity theory. These data suggest excess low vibrations contributing come largely from modes.