Electron mobility and infra-red absorption in reduced tin oxide crystals

We have prepared tin oxide crystals with greater purity than our previous samples, and have introduced electron densities between 10 17 and 10 18 cm −3 , by reduction in vacuum. The electron Hall mobility has been measured and is between 200 and 250 cm 2 v −1 s −1 at room temperature. The highest value we have observed at 77°K is 700 cm 2 v −1 s −1 . The infra-red absorption indicates that the scattering at 300°K is due to optical modes, and that the electron effective mass is 0·17 m 0 .