High-temperature conduction of granular metals

In theoretical and experimental studies of conductivity associated with int ergranular tunneling of electrons in nanocomposites (granular metals), only the range of relatively low temperatures was traditionally investigated, i n which only electron transitions involving singly-charged metal granules a re significant. In this mode, the temperature dependence of conductivity is exponential. However, experiments show that the type of conduction of nano composites at high temperatures changes significantly. In the model propose d in this article, the features of conduction of granular metals at high te mperatures are attributed to multiply charged granules with a large spread of the size. The conclusions of the model are in good agreement with the ex perimental results. (C) 2001 MAIK "Nauka/Interperiodica".