Molecular dynamics study of cage decay, near constant loss, and crossover to cooperative ion hopping in lithium metasilicate (original) (raw)

Molecular dynamics ͑MD͒ simulations of lithium metasilicate (Li 2 SiO 3) in the glassy and supercooled liquid states have been performed to illustrate the decay with time of the cages that confine individual Li ϩ ions before they hop out to diffuse cooperatively with each other. The self-part of the van Hove function of Li ϩ ions, G s (r,t), is used as an indicator of the cage decay. At 700 K, in the early time regime tϽt x1 , when the cage decays very slowly, the mean square displacement ͗r 2 ͘ of Li ϩ ions also increases very slowly with time approximately as t 0.1 and has weak temperature dependence. Such ͗r 2 ͘ can be identified with the near constant loss ͑NCL͒ observed in the dielectric response of ionic conductors. At longer times, when the cage decays more rapidly as indicated by the increasing buildup of the intensity of G s (r,t) at the distance between Li ϩ ion sites,

Sign up for access to the world's latest research.

checkGet notified about relevant papers

checkSave papers to use in your research

checkJoin the discussion with peers

checkTrack your impact