Pseudogap, nanocrystals and electrical conductivity of doped silicate glass

The ideas of pseudogap and nanocrystals have applied to mechanism of electrical conduction in silicate glass doped by oxides of transition metals (thick film resistors). Pseudogap is formed near the valence band of the glass due to diffusion of dopant atoms into the glass in calcination. Nanocrystals are generated in the glass in melting process and undergo structure transitions at high temperatures. This approach lets to explain the temperature dependence of conductivity of doped silicate glass from liquid helium up to 1100 K.