High-field conductivity in SnO2 glazes

The conductivity of glazes consisting of SnO₂ in Sb-doped BaAl-borate and BaAl-borosilicate glasses has been studied for fields in the range 10²–10⁵ V/cm at temperatures 4.2 K ? T ? 470 K. The glazes were free of mobile ions such as K, Na, Li and Pb. Conduction takes place between Sb-doped SnO₂ particles concentrated in the fused contact region between the much larger glass particles. At high temperatures (300–470 K), the conductivity is thermally activated of the Frenkel-Poole type. At 77 K, both tunneling and thermally activated conductivity appear to be present.