Percolation-like approach to resistivity behaviour of glassforming ionic melts

The Vogel-Fulcher equation (and percolation approach) predicts an infinite resistivity below the "ideal" glassification point T-0 (correspondingly- pe rcolation threshold). However, the ions still preserve a noticeable mobilit y within the real glasses even below To. T-0 model the finite resistivity i n glass a resistance R-max of a broken bond is introduced. The ratio of R-m ax/R-min in real glasses is about 10(14) and 1/R-max might be identified wi th a probability of tunnelling process. The comparison of calculations' res ult (with R-max/R-min = 10(7) or 10(9)) with our data on CKN is encouraging . (C) 1999 Elsevier Science B.V. All rights reserved.