15 nm is a significant gap for tunneling, but percolation conduction may be made easier through impurities already present in the glassy phase. If 15 nm is the mean distance, possibly in some zones the distance is lower and hence the tunneling (or the VRH or any other hopping mechanism) can take place. In this case, the overall conductivity should be strongly dependent of both temperature and electric field. There is nothing else to do but measuring, but I expect a rather low (but never zero) conductivity.

Alain

Thanks Alain,

yes, you are right that at some areas the distance might be lower than 15 nm, but strictly speaking it's not in the tunneling range. Since for tunneling the distance should be a few nm (

Conductivity may also occur by ion diffusion in glass. What is the order of magnitude of the conductivity you measured and at which tempretaure was it measurable ? I personally observed non-negligible conductivity is usual borosilicate glass above 100°C. Therefore, percolation may not be the only mechanism. For checking the relevance of ionic conductivity, you should do measurements as a function of temperature and see if Arrhenius' law applies.

Alain

One example of glass conductivity in Fig. 7 of the attached paper (in French, but at least you can understand the figures and the equation).

Alain

Hello Praveen and Alain

I would be happy to say you that I want to provide some information about percolation. First of all, to get the percolation effect of the system, we need the percolation network. Because , the structured of the network will decide the direction of charge transport (ie. 1D, 2D or 3D transport mechanism). I agree with Alain's explaination.  Praveen; according to your question , it seems that you want in plain charge transport phenomena. The percolation effect can be observed    through in plain charge transport mechanism. But the size of metal and insulating particle will also contribute in the one. So the network of your materials is big deal here.

Rakibul

Thanks Raki for your nice answer,

                   According to my results, i would expect a 3D percolation charge transport through the glass phase. Since, insulator in my case is the glass phase which contained a large no of metallic silver colloids and precipitates (for example Zn, Pb and also Ag). Ag colloids vary in size and are separated by